treewide: remove redundant IS_ERR() before error code check

[linux/fpc-iii.git] / Documentation / RCU / RTFP.txt

Read the Fscking Papers!


This document describes RCU-related publications, and is followed by
the corresponding bibtex entries.  A number of the publications may
be found at http://www.rdrop.com/users/paulmck/RCU/.  For others, browsers
and search engines will usually find what you are looking for.

The first thing resembling RCU was published in 1980, when Kung and Lehman
[Kung80] recommended use of a garbage collector to defer destruction
of nodes in a parallel binary search tree in order to simplify its
implementation.  This works well in environments that have garbage
collectors, but most production garbage collectors incur significant
overhead.

In 1982, Manber and Ladner [Manber82,Manber84] recommended deferring
destruction until all threads running at that time have terminated, again
for a parallel binary search tree.  This approach works well in systems
with short-lived threads, such as the K42 research operating system.
However, Linux has long-lived tasks, so more is needed.

In 1986, Hennessy, Osisek, and Seigh [Hennessy89] introduced passive
serialization, which is an RCU-like mechanism that relies on the presence
of "quiescent states" in the VM/XA hypervisor that are guaranteed not
to be referencing the data structure.  However, this mechanism was not
optimized for modern computer systems, which is not surprising given
that these overheads were not so expensive in the mid-80s.  Nonetheless,
passive serialization appears to be the first deferred-destruction
mechanism to be used in production.  Furthermore, the relevant patent
has lapsed, so this approach may be used in non-GPL software, if desired.
(In contrast, implementation of RCU is permitted only in software licensed
under either GPL or LGPL.  Sorry!!!)

In 1987, Rashid et al. described lazy TLB-flush [RichardRashid87a].
At first glance, this has nothing to do with RCU, but nevertheless
this paper helped inspire the update-side batching used in the later
RCU implementation in DYNIX/ptx.  In 1988, Barbara Liskov published
a description of Argus that noted that use of out-of-date values can
be tolerated in some situations.  Thus, this paper provides some early
theoretical justification for use of stale data.

In 1990, Pugh [Pugh90] noted that explicitly tracking which threads
were reading a given data structure permitted deferred free to operate
in the presence of non-terminating threads.  However, this explicit
tracking imposes significant read-side overhead, which is undesirable
in read-mostly situations.  This algorithm does take pains to avoid
write-side contention and parallelize the other write-side overheads by
providing a fine-grained locking design, however, it would be interesting
to see how much of the performance advantage reported in 1990 remains
today.

At about this same time, Andrews [Andrews91textbook] described ``chaotic
relaxation'', where the normal barriers between successive iterations
of convergent numerical algorithms are relaxed, so that iteration $n$
might use data from iteration $n-1$ or even $n-2$.  This introduces
error, which typically slows convergence and thus increases the number of
iterations required.  However, this increase is sometimes more than made
up for by a reduction in the number of expensive barrier operations,
which are otherwise required to synchronize the threads at the end
of each iteration.  Unfortunately, chaotic relaxation requires highly
structured data, such as the matrices used in scientific programs, and
is thus inapplicable to most data structures in operating-system kernels.

In 1992, Henry (now Alexia) Massalin completed a dissertation advising
parallel programmers to defer processing when feasible to simplify
synchronization [HMassalinPhD].  RCU makes extremely heavy use of
this advice.

In 1993, Jacobson [Jacobson93] verbally described what is perhaps the
simplest deferred-free technique: simply waiting a fixed amount of time
before freeing blocks awaiting deferred free.  Jacobson did not describe
any write-side changes he might have made in this work using SGI's Irix
kernel.  Aju John published a similar technique in 1995 [AjuJohn95].
This works well if there is a well-defined upper bound on the length of
time that reading threads can hold references, as there might well be in
hard real-time systems.  However, if this time is exceeded, perhaps due
to preemption, excessive interrupts, or larger-than-anticipated load,
memory corruption can ensue, with no reasonable means of diagnosis.
Jacobson's technique is therefore inappropriate for use in production
operating-system kernels, except when such kernels can provide hard
real-time response guarantees for all operations.

Also in 1995, Pu et al. [Pu95a] applied a technique similar to that of Pugh's
read-side-tracking to permit replugging of algorithms within a commercial
Unix operating system.  However, this replugging permitted only a single
reader at a time.  The following year, this same group of researchers
extended their technique to allow for multiple readers [Cowan96a].
Their approach requires memory barriers (and thus pipeline stalls),
but reduces memory latency, contention, and locking overheads.

1995 also saw the first publication of DYNIX/ptx's RCU mechanism
[Slingwine95], which was optimized for modern CPU architectures,
and was successfully applied to a number of situations within the
DYNIX/ptx kernel.  The corresponding conference paper appeared in 1998
[McKenney98].

In 1999, the Tornado and K42 groups described their "generations"
mechanism, which is quite similar to RCU [Gamsa99].  These operating
systems made pervasive use of RCU in place of "existence locks", which
greatly simplifies locking hierarchies and helps avoid deadlocks.

The year 2000 saw an email exchange that would likely have
led to yet another independent invention of something like RCU
[RustyRussell2000a,RustyRussell2000b].  Instead, 2001 saw the first
RCU presentation involving Linux [McKenney01a] at OLS.  The resulting
abundance of RCU patches was presented the following year [McKenney02a],
and use of RCU in dcache was first described that same year [Linder02a].

Also in 2002, Michael [Michael02b,Michael02a] presented "hazard-pointer"
techniques that defer the destruction of data structures to simplify
non-blocking synchronization (wait-free synchronization, lock-free
synchronization, and obstruction-free synchronization are all examples of
non-blocking synchronization).  The corresponding journal article appeared
in 2004 [MagedMichael04a].  This technique eliminates locking, reduces
contention, reduces memory latency for readers, and parallelizes pipeline
stalls and memory latency for writers.  However, these techniques still
impose significant read-side overhead in the form of memory barriers.
Researchers at Sun worked along similar lines in the same timeframe
[HerlihyLM02].  These techniques can be thought of as inside-out reference
counts, where the count is represented by the number of hazard pointers
referencing a given data structure rather than the more conventional
counter field within the data structure itself.  The key advantage
of inside-out reference counts is that they can be stored in immortal
variables, thus allowing races between access and deletion to be avoided.

By the same token, RCU can be thought of as a "bulk reference count",
where some form of reference counter covers all reference by a given CPU
or thread during a set timeframe.  This timeframe is related to, but
not necessarily exactly the same as, an RCU grace period.  In classic
RCU, the reference counter is the per-CPU bit in the "bitmask" field,
and each such bit covers all references that might have been made by
the corresponding CPU during the prior grace period.  Of course, RCU
can be thought of in other terms as well.

In 2003, the K42 group described how RCU could be used to create
hot-pluggable implementations of operating-system functions [Appavoo03a].
Later that year saw a paper describing an RCU implementation
of System V IPC [Arcangeli03] (following up on a suggestion by
Hugh Dickins [Dickins02a] and an implementation by Mingming Cao
[MingmingCao2002IPCRCU]), and an introduction to RCU in Linux Journal
[McKenney03a].

2004 has seen a Linux-Journal article on use of RCU in dcache
[McKenney04a], a performance comparison of locking to RCU on several
different CPUs [McKenney04b], a dissertation describing use of RCU in a
number of operating-system kernels [PaulEdwardMcKenneyPhD], a paper
describing how to make RCU safe for soft-realtime applications [Sarma04c],
and a paper describing SELinux performance with RCU [JamesMorris04b].

2005 brought further adaptation of RCU to realtime use, permitting
preemption of RCU realtime critical sections [PaulMcKenney05a,
PaulMcKenney05b].

2006 saw the first best-paper award for an RCU paper [ThomasEHart2006a],
as well as further work on efficient implementations of preemptible
RCU [PaulEMcKenney2006b], but priority-boosting of RCU read-side critical
sections proved elusive.  An RCU implementation permitting general
blocking in read-side critical sections appeared [PaulEMcKenney2006c],
Robert Olsson described an RCU-protected trie-hash combination
[RobertOlsson2006a].

2007 saw the journal version of the award-winning RCU paper from 2006
[ThomasEHart2007a], as well as a paper demonstrating use of Promela
and Spin to mechanically verify an optimization to Oleg Nesterov's
QRCU [PaulEMcKenney2007QRCUspin], a design document describing
preemptible RCU [PaulEMcKenney2007PreemptibleRCU], and the three-part
LWN "What is RCU?" series [PaulEMcKenney2007WhatIsRCUFundamentally,
PaulEMcKenney2008WhatIsRCUUsage, and PaulEMcKenney2008WhatIsRCUAPI].

2008 saw a journal paper on real-time RCU [DinakarGuniguntala2008IBMSysJ],
a history of how Linux changed RCU more than RCU changed Linux
[PaulEMcKenney2008RCUOSR], and a design overview of hierarchical RCU
[PaulEMcKenney2008HierarchicalRCU].

2009 introduced user-level RCU algorithms [PaulEMcKenney2009MaliciousURCU],
which Mathieu Desnoyers is now maintaining [MathieuDesnoyers2009URCU]
[MathieuDesnoyersPhD].  TINY_RCU [PaulEMcKenney2009BloatWatchRCU] made
its appearance, as did expedited RCU [PaulEMcKenney2009expeditedRCU].
The problem of resizable RCU-protected hash tables may now be on a path
to a solution [JoshTriplett2009RPHash].  A few academic researchers are now
using RCU to solve their parallel problems [HariKannan2009DynamicAnalysisRCU].

2010 produced a simpler preemptible-RCU implementation
based on TREE_RCU [PaulEMcKenney2010SimpleOptRCU], lockdep-RCU
[PaulEMcKenney2010LockdepRCU], another resizable RCU-protected hash
table [HerbertXu2010RCUResizeHash] (this one consuming more memory,
but allowing arbitrary changes in hash function, as required for DoS
avoidance in the networking code), realization of the 2009 RCU-protected
hash table with atomic node move [JoshTriplett2010RPHash], an update on
the RCU API [PaulEMcKenney2010RCUAPI].

2011 marked the inclusion of Nick Piggin's fully lockless dentry search
[LinusTorvalds2011Linux2:6:38:rc1:NPigginVFS], an RCU-protected red-black
tree using software transactional memory to protect concurrent updates
(strange, but true!) [PhilHoward2011RCUTMRBTree], yet another variant of
RCU-protected resizable hash tables [Triplett:2011:RPHash], the 3.0 RCU
trainwreck [PaulEMcKenney2011RCU3.0trainwreck], and Neil Brown's "Meet the
Lockers" LWN article [NeilBrown2011MeetTheLockers].  Some academic
work looked at debugging uses of RCU [Seyster:2011:RFA:2075416.2075425].

In 2012, Josh Triplett received his Ph.D. with his dissertation
covering RCU-protected resizable hash tables and the relationship
between memory barriers and read-side traversal order:  If the updater
is making changes in the opposite direction from the read-side traveral
order, the updater need only execute a memory-barrier instruction,
but if in the same direction, the updater needs to wait for a grace
period between the individual updates [JoshTriplettPhD].  Also in 2012,
after seventeen years of attempts, an RCU paper made it into a top-flight
academic journal, IEEE Transactions on Parallel and Distributed Systems
[MathieuDesnoyers2012URCU].  A group of researchers in Spain applied
user-level RCU to crowd simulation [GuillermoVigueras2012RCUCrowd], and
another group of researchers in Europe produced a formal description of
RCU based on separation logic [AlexeyGotsman2012VerifyGraceExtended],
which was published in the 2013 European Symposium on Programming
[AlexeyGotsman2013ESOPRCU].



Bibtex Entries

@article{Kung80
,author="H. T. Kung and Q. Lehman"
,title="Concurrent Manipulation of Binary Search Trees"
,Year="1980"
,Month="September"
,journal="ACM Transactions on Database Systems"
,volume="5"
,number="3"
,pages="354-382"
,annotation={
        Use garbage collector to clean up data after everyone is done with it.
        .
        Oldest use of something vaguely resembling RCU that I have found.
        http://portal.acm.org/citation.cfm?id=320619&dl=GUIDE,
        [Viewed December 3, 2007]
}
}

@techreport{Manber82
,author="Udi Manber and Richard E. Ladner"
,title="Concurrency Control in a Dynamic Search Structure"
,institution="Department of Computer Science, University of Washington"
,address="Seattle, Washington"
,year="1982"
,number="82-01-01"
,month="January"
,pages="28"
,annotation={
        .
        Superseded by Manber84.
        .
        Describes concurrent AVL tree implementation.  Uses a
        garbage-collection mechanism to handle concurrent use and deletion
        of nodes in the tree, but lacks the summary-of-execution-history
        concept of read-copy locking.
        .
        Keeps full list of processes that were active when a given
        node was to be deleted, and waits until all such processes have
        -terminated- before allowing this node to be reused.  This is
        not described in great detail -- one could imagine using process
        IDs for this if the ID space was large enough that overlapping
        never occurred.
        .
        This restriction makes this algorithm unsuitable for use in
        systems comprised of long-lived processes.  It also produces
        completely unacceptable overhead in systems with large numbers
        of processes.  Finally, it is specific to AVL trees.
        .
        Cites Kung80, so not an independent invention, but the first
        RCU-like usage that does not rely on an automatic garbage
        collector.
}
}

@article{Manber84
,author="Udi Manber and Richard E. Ladner"
,title="Concurrency Control in a Dynamic Search Structure"
,Year="1984"
,Month="September"
,journal="ACM Transactions on Database Systems"
,volume="9"
,number="3"
,pages="439-455"
,annotation={
        Describes concurrent AVL tree implementation.  Uses a
        garbage-collection mechanism to handle concurrent use and deletion
        of nodes in the tree, but lacks the summary-of-execution-history
        concept of read-copy locking.
        .
        Keeps full list of processes that were active when a given
        node was to be deleted, and waits until all such processes have
        -terminated- before allowing this node to be reused.  This is
        not described in great detail -- one could imagine using process
        IDs for this if the ID space was large enough that overlapping
        never occurred.
        .
        This restriction makes this algorithm unsuitable for use in
        systems comprised of long-lived processes.  It also produces
        completely unacceptable overhead in systems with large numbers
        of processes.  Finally, it is specific to AVL trees.
}
}

@Conference{RichardRashid87a
,Author="Richard Rashid and Avadis Tevanian and Michael Young and
David Golub and Robert Baron and David Black and William Bolosky and
Jonathan Chew"
,Title="Machine-Independent Virtual Memory Management for Paged
Uniprocessor and Multiprocessor Architectures"
,Booktitle="{2\textsuperscript{nd} Symposium on Architectural Support
for Programming Languages and Operating Systems}"
,Publisher="Association for Computing Machinery"
,Month="October"
,Year="1987"
,pages="31-39"
,Address="Palo Alto, CA"
,note="Available:
\url{http://www.cse.ucsc.edu/~randal/221/rashid-machvm.pdf}
[Viewed February 17, 2005]"
,annotation={
        Describes lazy TLB flush, where one waits for each CPU to pass
        through a scheduling-clock interrupt before reusing a given range
        of virtual address.  Does not describe how one determines that
        all CPUs have in fact taken such an interrupt, though there are
        no shortage of straightforward methods for accomplishing this.
        .
        Note that it does not make sense to just wait a fixed amount of
        time, since a given CPU might have interrupts disabled for an
        extended amount of time.
}
}

@article{BarbaraLiskov1988ArgusCACM
,author = {Barbara Liskov}
,title = {Distributed programming in {Argus}}
,journal = {Commun. ACM}
,volume = {31}
,number = {3}
,year = {1988}
,issn = {0001-0782}
,pages = {300--312}
,doi = {http://doi.acm.org/10.1145/42392.42399}
,publisher = {ACM}
,address = {New York, NY, USA}
,annotation={
        At the top of page 307: "Conflicts with deposits and withdrawals
        are necessary if the reported total is to be up to date.  They
        could be avoided by having total return a sum that is slightly
        out of date."  Relies on semantics -- approximate numerical
        values sometimes OK.
}
}

@techreport{Hennessy89
,author="James P. Hennessy and Damian L. Osisek and Joseph W. {Seigh II}"
,title="Passive Serialization in a Multitasking Environment"
,institution="US Patent and Trademark Office"
,address="Washington, DC"
,year="1989"
,number="US Patent 4,809,168 (lapsed)"
,month="February"
,pages="11"
}

@techreport{Pugh90
,author="William Pugh"
,title="Concurrent Maintenance of Skip Lists"
,institution="Institute of Advanced Computer Science Studies, Department of Computer Science, University of Maryland"
,address="College Park, Maryland"
,year="1990"
,number="CS-TR-2222.1"
,month="June"
,annotation={
        Concurrent access to skip lists.  Has both weak and strong search.
        Uses concept of ``garbage queue'', but has no real way of cleaning
        the garbage efficiently.
        .
        Appears to be an independent invention of an RCU-like mechanism.
}
}

# Was Adams91, see also syncrefs.bib.
@Book{Andrews91textbook
,Author="Gregory R. Andrews"
,title="Concurrent Programming, Principles, and Practices"
,Publisher="Benjamin Cummins"
,Year="1991"
,annotation={
        Has a few paragraphs describing ``chaotic relaxation'', a
        numerical analysis technique that allows multiprocessors to
        avoid synchronization overhead by using possibly-stale data.
        .
        Seems like this is descended from yet another independent
        invention of RCU-like function -- but this is restricted
        in that reclamation is not necessary.
}
}

@phdthesis{HMassalinPhD
,author="H. Massalin"
,title="Synthesis: An Efficient Implementation of Fundamental Operating
System Services"
,school="Columbia University"
,address="New York, NY"
,year="1992"
,annotation={
        Mondo optimizing compiler.
        Wait-free stuff.
        Good advice: defer work to avoid synchronization.  See page 90
                (PDF page 106), Section 5.4, fourth bullet point.
}
}

@unpublished{Jacobson93
,author="Van Jacobson"
,title="Avoid Read-Side Locking Via Delayed Free"
,year="1993"
,month="September"
,note="private communication"
,annotation={
        Use fixed time delay to approximate grace period.  Very simple,
        but subject to random memory corruption under heavy load.
        .
        Independent invention of RCU-like mechanism.
}
}

@Conference{AjuJohn95
,Author="Aju John"
,Title="Dynamic vnodes -- Design and Implementation"
,Booktitle="{USENIX Winter 1995}"
,Publisher="USENIX Association"
,Month="January"
,Year="1995"
,pages="11-23"
,Address="New Orleans, LA"
,note="Available:
\url{https://www.usenix.org/publications/library/proceedings/neworl/full_papers/john.a}
[Viewed October 1, 2010]"
,annotation={
        Age vnodes out of the cache, and have a fixed time set by a kernel
        parameter.  Not clear that all races were in fact correctly handled.
        Used a 20-minute time by default, which would most definitely not
        be suitable during DoS attacks or virus scans.
        .
        Apparently independent invention of RCU-like mechanism.
}
}

@conference{Pu95a
,Author = "Calton Pu and Tito Autrey and Andrew Black and Charles Consel and
Crispin Cowan and Jon Inouye and Lakshmi Kethana and Jonathan Walpole and
Ke Zhang"
,Title = "Optimistic Incremental Specialization: Streamlining a Commercial
,Operating System"
,Booktitle = "15\textsuperscript{th} ACM Symposium on
,Operating Systems Principles (SOSP'95)"
,address = "Copper Mountain, CO"
,month="December"
,year="1995"
,pages="314-321"
,annotation={
        Uses a replugger, but with a flag to signal when people are
        using the resource at hand.  Only one reader at a time.
}
}

@conference{Cowan96a
,Author = "Crispin Cowan and Tito Autrey and Charles Krasic and
,Calton Pu and Jonathan Walpole"
,Title = "Fast Concurrent Dynamic Linking for an Adaptive Operating System"
,Booktitle = "International Conference on Configurable Distributed Systems
(ICCDS'96)"
,address = "Annapolis, MD"
,month="May"
,year="1996"
,pages="108"
,isbn="0-8186-7395-8"
,annotation={
        Uses a replugger, but with a counter to signal when people are
        using the resource at hand.  Allows multiple readers.
}
}

@techreport{Slingwine95
,author="John D. Slingwine and Paul E. McKenney"
,title="Apparatus and Method for Achieving Reduced Overhead Mutual
Exclusion and Maintaining Coherency in a Multiprocessor System
Utilizing Execution History and Thread Monitoring"
,institution="US Patent and Trademark Office"
,address="Washington, DC"
,year="1995"
,number="US Patent 5,442,758"
,month="August"
,annotation={
        Describes the parallel RCU infrastructure.  Includes NUMA aspect
        (structure of bitmap can reflect bus structure of computer system).
        .
        Another independent invention of an RCU-like mechanism, but the
        "real" RCU this time!
}
}

@techreport{Slingwine97
,author="John D. Slingwine and Paul E. McKenney"
,title="Method for Maintaining Data Coherency Using Thread Activity
Summaries in a Multicomputer System"
,institution="US Patent and Trademark Office"
,address="Washington, DC"
,year="1997"
,number="US Patent 5,608,893"
,month="March"
,pages="19"
,annotation={
        Describes use of RCU to synchronize data between a pair of
        SMP/NUMA computer systems.
}
}

@techreport{Slingwine98
,author="John D. Slingwine and Paul E. McKenney"
,title="Apparatus and Method for Achieving Reduced Overhead Mutual
Exclusion and Maintaining Coherency in a Multiprocessor System
Utilizing Execution History and Thread Monitoring"
,institution="US Patent and Trademark Office"
,address="Washington, DC"
,year="1998"
,number="US Patent 5,727,209"
,month="March"
,annotation={
        Describes doing an atomic update by copying the data item and
        then substituting it into the data structure.
}
}

@Conference{McKenney98
,Author="Paul E. McKenney and John D. Slingwine"
,Title="Read-Copy Update: Using Execution History to Solve Concurrency
Problems"
,Booktitle="{Parallel and Distributed Computing and Systems}"
,Month="October"
,Year="1998"
,pages="509-518"
,Address="Las Vegas, NV"
,annotation={
        Describes and analyzes RCU mechanism in DYNIX/ptx.  Describes
        application to linked list update and log-buffer flushing.
        Defines 'quiescent state'.  Includes both measured and analytic
        evaluation.
        http://www.rdrop.com/users/paulmck/RCU/rclockpdcsproof.pdf
        [Viewed December 3, 2007]
}
}

@Conference{Gamsa99
,Author="Ben Gamsa and Orran Krieger and Jonathan Appavoo and Michael Stumm"
,Title="Tornado: Maximizing Locality and Concurrency in a Shared Memory
Multiprocessor Operating System"
,Booktitle="{Proceedings of the 3\textsuperscript{rd} Symposium on
Operating System Design and Implementation}"
,Month="February"
,Year="1999"
,pages="87-100"
,Address="New Orleans, LA"
,annotation={
        Use of RCU-like facility in K42/Tornado.  Another independent
        invention of RCU.
        See especially pages 7-9 (Section 5).
        http://www.usenix.org/events/osdi99/full_papers/gamsa/gamsa.pdf
        [Viewed August 30, 2006]
}
}

@unpublished{RustyRussell2000a
,Author="Rusty Russell"
,Title="Re: modular net drivers"
,month="June"
,year="2000"
,day="23"
,note="Available:
\url{http://oss.sgi.com/projects/netdev/archive/2000-06/msg00250.html}
[Viewed April 10, 2006]"
,annotation={
        Proto-RCU proposal from Phil Rumpf and Rusty Russell.
        Yet another independent invention of RCU.
        Outline of algorithm to unload modules...
        .
        Appeared on net-dev mailing list.
}
}

@unpublished{RustyRussell2000b
,Author="Rusty Russell"
,Title="Re: modular net drivers"
,month="June"
,year="2000"
,day="24"
,note="Available:
\url{http://oss.sgi.com/projects/netdev/archive/2000-06/msg00254.html}
[Viewed April 10, 2006]"
,annotation={
        Proto-RCU proposal from Phil Rumpf and Rusty Russell.
        .
        Appeared on net-dev mailing list.
}
}

@unpublished{McKenney01b
,Author="Paul E. McKenney and Dipankar Sarma"
,Title="Read-Copy Update Mutual Exclusion in {Linux}"
,month="February"
,year="2001"
,note="Available:
\url{http://lse.sourceforge.net/locking/rcu/rcupdate_doc.html}
[Viewed October 18, 2004]"
,annotation={
        Prototypical Linux documentation for RCU.
}
}

@techreport{Slingwine01
,author="John D. Slingwine and Paul E. McKenney"
,title="Apparatus and Method for Achieving Reduced Overhead Mutual
Exclusion and Maintaining Coherency in a Multiprocessor System
Utilizing Execution History and Thread Monitoring"
,institution="US Patent and Trademark Office"
,address="Washington, DC"
,year="2001"
,number="US Patent 6,219,690"
,month="April"
,annotation={
        'Change in mode' aspect of RCU.  Can be thought of as a lazy barrier.
}
}

@Conference{McKenney01a
,Author="Paul E. McKenney and Jonathan Appavoo and Andi Kleen and
Orran Krieger and Rusty Russell and Dipankar Sarma and Maneesh Soni"
,Title="Read-Copy Update"
,Booktitle="{Ottawa Linux Symposium}"
,Month="July"
,Year="2001"
,note="Available:
\url{http://www.linuxsymposium.org/2001/abstracts/readcopy.php}
\url{http://www.rdrop.com/users/paulmck/RCU/rclock_OLS.2001.05.01c.pdf}
[Viewed June 23, 2004]"
,annotation={
        Described RCU, and presented some patches implementing and using
        it in the Linux kernel.
}
}

@unpublished{McKenney01f
,Author="Paul E. McKenney"
,Title="{RFC:} patch to allow lock-free traversal of lists with insertion"
,month="October"
,year="2001"
,note="Available:
\url{http://marc.theaimsgroup.com/?l=linux-kernel&m=100259266316456&w=2}
[Viewed June 23, 2004]"
,annotation={
        Memory-barrier and Alpha thread.  100 messages, not too bad...
}
}

@unpublished{Spraul01
,Author="Manfred Spraul"
,Title="Re: {RFC:} patch to allow lock-free traversal of lists with insertion"
,month="October"
,year="2001"
,note="Available:
\url{http://marc.theaimsgroup.com/?l=linux-kernel&m=100264675012867&w=2}
[Viewed June 23, 2004]"
,annotation={
        Suggested burying memory barriers in Linux's list-manipulation
        primitives.
}
}

@unpublished{LinusTorvalds2001a
,Author="Linus Torvalds"
,Title="{Re:} {[Lse-tech]} {Re:} {RFC:} patch to allow lock-free traversal of lists with insertion"
,month="October"
,year="2001"
,note="Available:
\url{http://lkml.org/lkml/2001/10/13/105}
[Viewed August 21, 2004]"
,annotation={
}
}

@unpublished{Blanchard02a
,Author="Anton Blanchard"
,Title="some RCU dcache and ratcache results"
,month="March"
,year="2002"
,note="Available:
\url{http://marc.theaimsgroup.com/?l=linux-kernel&m=101637107412972&w=2}
[Viewed October 18, 2004]"
}

@conference{Michael02b
,author="Maged M. Michael"
,title="High Performance Dynamic Lock-Free Hash Tables and List-Based Sets"
,Year="2002"
,Month="August"
,booktitle="{Proceedings of the 14\textsuperscript{th} Annual ACM
Symposium on Parallel
Algorithms and Architecture}"
,pages="73-82"
,annotation={
Like the title says...
}
}

@Conference{Linder02a
,Author="Hanna Linder and Dipankar Sarma and Maneesh Soni"
,Title="Scalability of the Directory Entry Cache"
,Booktitle="{Ottawa Linux Symposium}"
,Month="June"
,Year="2002"
,pages="289-300"
,annotation={
        Measured scalability of Linux 2.4 kernel's directory-entry cache
        (dcache), and measured some scalability enhancements.
}
}

@Conference{McKenney02a
,Author="Paul E. McKenney and Dipankar Sarma and
Andrea Arcangeli and Andi Kleen and Orran Krieger and Rusty Russell"
,Title="Read-Copy Update"
,Booktitle="{Ottawa Linux Symposium}"
,Month="June"
,Year="2002"
,pages="338-367"
,note="Available:
\url{http://www.linux.org.uk/~ajh/ols2002_proceedings.pdf.gz}
[Viewed June 23, 2004]"
,annotation={
        Presented and compared a number of RCU implementations for the
        Linux kernel.
}
}

@unpublished{Sarma02a
,Author="Dipankar Sarma"
,Title="specweb99: dcache scalability results"
,month="July"
,year="2002"
,note="Available:
\url{http://marc.theaimsgroup.com/?l=linux-kernel&m=102645767914212&w=2}
[Viewed June 23, 2004]"
,annotation={
        Compare fastwalk and RCU for dcache.  RCU won.
}
}

@unpublished{Barbieri02
,Author="Luca Barbieri"
,Title="Re: {[PATCH]} Initial support for struct {vfs\_cred}"
,month="August"
,year="2002"
,note="Available:
\url{http://marc.theaimsgroup.com/?l=linux-kernel&m=103082050621241&w=2}
[Viewed: June 23, 2004]"
,annotation={
        Suggested RCU for vfs\_shared\_cred.
}
}

@conference{Michael02a
,author="Maged M. Michael"
,title="Safe Memory Reclamation for Dynamic Lock-Free Objects Using Atomic
Reads and Writes"
,Year="2002"
,Month="August"
,booktitle="{Proceedings of the 21\textsuperscript{st} Annual ACM
Symposium on Principles of Distributed Computing}"
,pages="21-30"
,annotation={
        Each thread keeps an array of pointers to items that it is
        currently referencing.  Sort of an inside-out garbage collection
        mechanism, but one that requires the accessing code to explicitly
        state its needs.  Also requires read-side memory barriers on
        most architectures.
}
}

@unpublished{Dickins02a
,author="Hugh Dickins"
,title="Use RCU for System-V IPC"
,year="2002"
,month="October"
,note="private communication"
}

@InProceedings{HerlihyLM02
,author={Maurice Herlihy and Victor Luchangco and Mark Moir}
,title="The Repeat Offender Problem: A Mechanism for Supporting Dynamic-Sized,
Lock-Free Data Structures"
,booktitle={Proceedings of 16\textsuperscript{th} International
Symposium on Distributed Computing}
,year=2002
,month="October"
,pages="339-353"
}

@unpublished{Sarma02b
,Author="Dipankar Sarma"
,Title="Some dcache\_rcu benchmark numbers"
,month="October"
,year="2002"
,note="Available:
\url{http://marc.theaimsgroup.com/?l=linux-kernel&m=103462075416638&w=2}
[Viewed June 23, 2004]"
,annotation={
        Performance of dcache RCU on kernbench for 16x NUMA-Q and 1x,
        2x, and 4x systems.  RCU does no harm, and helps on 16x.
}
}

@unpublished{MingmingCao2002IPCRCU
,Author="Mingming Cao"
,Title="[PATCH]updated ipc lock patch"
,month="October"
,year="2002"
,note="Available:
\url{https://lkml.org/lkml/2002/10/24/262}
[Viewed February 15, 2014]"
,annotation={
        Mingming Cao's patch to introduce RCU to SysV IPC.
}
}

@unpublished{LinusTorvalds2003a
,Author="Linus Torvalds"
,Title="Re: {[PATCH]} small fixes in brlock.h"
,month="March"
,year="2003"
,note="Available:
\url{http://lkml.org/lkml/2003/3/9/205}
[Viewed March 13, 2006]"
,annotation={
        Linus suggests replacing brlock with RCU and/or seqlocks:
        .
        'It's entirely possible that the current user could be replaced
        by RCU and/or seqlocks, and we could get rid of brlocks entirely.'
        .
        Steve Hemminger responds by replacing them with RCU.
}
}

@article{Appavoo03a
,author="J. Appavoo and K. Hui and C. A. N. Soules and R. W. Wisniewski and
D. M. {Da Silva} and O. Krieger and M. A. Auslander and D. J. Edelsohn and
B. Gamsa and G. R. Ganger and P. McKenney and M. Ostrowski and
B. Rosenburg and M. Stumm and J. Xenidis"
,title="Enabling Autonomic Behavior in Systems Software With Hot Swapping"
,Year="2003"
,Month="January"
,journal="IBM Systems Journal"
,volume="42"
,number="1"
,pages="60-76"
,annotation={
        Use of RCU to enable hot-swapping for autonomic behavior in K42.
}
}

@unpublished{Seigh03
,author="Joseph W. {Seigh II}"
,title="Read Copy Update"
,Year="2003"
,Month="March"
,note="email correspondence"
,annotation={
        Described the relationship of the VM/XA passive serialization to RCU.
}
}

@Conference{Arcangeli03
,Author="Andrea Arcangeli and Mingming Cao and Paul E. McKenney and
Dipankar Sarma"
,Title="Using Read-Copy Update Techniques for {System V IPC} in the
{Linux} 2.5 Kernel"
,Booktitle="Proceedings of the 2003 USENIX Annual Technical Conference
(FREENIX Track)"
,Publisher="USENIX Association"
,year="2003"
,month="June"
,pages="297-310"
,annotation={
        Compared updated RCU implementations for the Linux kernel, and
        described System V IPC use of RCU, including order-of-magnitude
        performance improvements.
        http://www.rdrop.com/users/paulmck/RCU/rcu.FREENIX.2003.06.14.pdf
}
}

@Conference{Soules03a
,Author="Craig A. N. Soules and Jonathan Appavoo and Kevin Hui and
Dilma {Da Silva} and Gregory R. Ganger and Orran Krieger and
Michael Stumm and Robert W. Wisniewski and Marc Auslander and
Michal Ostrowski and Bryan Rosenburg and Jimi Xenidis"
,Title="System Support for Online Reconfiguration"
,Booktitle="Proceedings of the 2003 USENIX Annual Technical Conference"
,Publisher="USENIX Association"
,year="2003"
,month="June"
,pages="141-154"
}

@article{McKenney03a
,author="Paul E. McKenney"
,title="Using {RCU} in the {Linux} 2.5 Kernel"
,Year="2003"
,Month="October"
,journal="Linux Journal"
,volume="1"
,number="114"
,pages="18-26"
,note="Available:
\url{http://www.linuxjournal.com/article/6993}
[Viewed November 14, 2007]"
,annotation={
        Reader-friendly intro to RCU, with the infamous old-man-and-brat
        cartoon.
}
}

@unpublished{Sarma03a
,Author="Dipankar Sarma"
,Title="RCU low latency patches"
,month="December"
,year="2003"
,note="Message ID: 20031222180114.GA2248@in.ibm.com"
,annotation={
        dipankar/ct.2004.03.27/RCUll.2003.12.22.patch
}
}

@techreport{Friedberg03a
,author="Stuart A. Friedberg"
,title="Lock-Free Wild Card Search Data Structure and Method"
,institution="US Patent and Trademark Office"
,address="Washington, DC"
,year="2003"
,number="US Patent 6,662,184"
,month="December"
,pages="112"
,annotation={
        Applies RCU to a wildcard-search Patricia tree in order to permit
        synchronization-free lookup.  RCU is used to retain removed nodes
        for a grace period before freeing them.
}
}

@article{McKenney04a
,author="Paul E. McKenney and Dipankar Sarma and Maneesh Soni"
,title="Scaling dcache with {RCU}"
,Year="2004"
,Month="January"
,journal="Linux Journal"
,volume="1"
,number="118"
,pages="38-46"
,annotation={
        Reader friendly intro to dcache and RCU.
        http://www.linuxjournal.com/node/7124
        [Viewed December 26, 2010]
}
}

@Conference{McKenney04b
,Author="Paul E. McKenney"
,Title="{RCU} vs. Locking Performance on Different {CPUs}"
,Booktitle="{linux.conf.au}"
,Month="January"
,Year="2004"
,Address="Adelaide, Australia"
,note="Available:
\url{http://www.linux.org.au/conf/2004/abstracts.html#90}
\url{http://www.rdrop.com/users/paulmck/RCU/lockperf.2004.01.17a.pdf}
[Viewed June 23, 2004]"
,annotation={
        Compares performance of RCU to that of other locking primitives
        over a number of CPUs (x86, Opteron, Itanium, and PPC).
}
}

@unpublished{Sarma04a
,Author="Dipankar Sarma"
,Title="{[PATCH]} {RCU} for low latency (experimental)"
,month="March"
,year="2004"
,note="\url{http://marc.theaimsgroup.com/?l=linux-kernel&m=108003746402892&w=2}"
,annotation={
        Head of thread: dipankar/2004.03.23/rcu-low-lat.1.patch
}
}

@unpublished{Sarma04b
,Author="Dipankar Sarma"
,Title="Re: {[PATCH]} {RCU} for low latency (experimental)"
,month="March"
,year="2004"
,note="\url{http://marc.theaimsgroup.com/?l=linux-kernel&m=108016474829546&w=2}"
,annotation={
        dipankar/rcuth.2004.03.24/rcu-throttle.patch
}
}

@unpublished{Spraul04a
,Author="Manfred Spraul"
,Title="[RFC] 0/5 rcu lock update"
,month="May"
,year="2004"
,note="Available:
\url{http://marc.theaimsgroup.com/?l=linux-kernel&m=108546407726602&w=2}
[Viewed June 23, 2004]"
,annotation={
        Hierarchical-bitmap patch for RCU infrastructure.
}
}

@unpublished{Steiner04a
,Author="Jack Steiner"
,Title="Re: [Lse-tech] [RFC, PATCH] 1/5 rcu lock update:
Add per-cpu batch counter"
,month="May"
,year="2004"
,note="Available:
\url{http://marc.theaimsgroup.com/?l=linux-kernel&m=108551764515332&w=2}
[Viewed June 23, 2004]"
,annotation={
        RCU runs reasonably on a 512-CPU SGI using Manfred Spraul's patches,
        which may be found at:
        https://lkml.org/lkml/2004/5/20/49 (split vars into cachelines)
        https://lkml.org/lkml/2004/5/22/114 (cpu_quiet() patch)
        https://lkml.org/lkml/2004/5/25/24 (0/5)
        https://lkml.org/lkml/2004/5/25/23 (1/5)
                https://lkml.org/lkml/2004/5/25/265 (works for Jack)
        https://lkml.org/lkml/2004/5/25/20 (2/5)
        https://lkml.org/lkml/2004/5/25/22 (3/5)
        https://lkml.org/lkml/2004/5/25/19 (4/5)
        https://lkml.org/lkml/2004/5/25/21 (5/5)
}
}

@Conference{Sarma04c
,Author="Dipankar Sarma and Paul E. McKenney"
,Title="Making {RCU} Safe for Deep Sub-Millisecond Response
Realtime Applications"
,Booktitle="Proceedings of the 2004 USENIX Annual Technical Conference
(FREENIX Track)"
,Publisher="USENIX Association"
,year="2004"
,month="June"
,pages="182-191"
,annotation={
        Describes and compares a number of modifications to the Linux RCU
        implementation that make it friendly to realtime applications.
        https://www.usenix.org/conference/2004-usenix-annual-technical-conference/making-rcu-safe-deep-sub-millisecond-response
        [Viewed July 26, 2012]
}
}

@article{MagedMichael04a
,author="Maged M. Michael"
,title="Hazard Pointers: Safe Memory Reclamation for Lock-Free Objects"
,Year="2004"
,Month="June"
,journal="IEEE Transactions on Parallel and Distributed Systems"
,volume="15"
,number="6"
,pages="491-504"
,url="Available:
\url{http://www.research.ibm.com/people/m/michael/ieeetpds-2004.pdf}
[Viewed March 1, 2005]"
,annotation={
        New canonical hazard-pointer citation.
}
}

@phdthesis{PaulEdwardMcKenneyPhD
,author="Paul E. McKenney"
,title="Exploiting Deferred Destruction:
An Analysis of Read-Copy-Update Techniques
in Operating System Kernels"
,school="OGI School of Science and Engineering at
Oregon Health and Sciences University"
,year="2004"
,annotation={
        Describes RCU implementations and presents design patterns
        corresponding to common uses of RCU in several operating-system
        kernels.
        http://www.rdrop.com/users/paulmck/RCU/RCUdissertation.2004.07.14e1.pdf
        [Viewed October 15, 2004]
}
}

@unpublished{PaulEMcKenney2004rcu:dereference
,Author="Dipankar Sarma"
,Title="{Re: RCU : Abstracted RCU dereferencing [5/5]}"
,month="August"
,year="2004"
,note="Available:
\url{http://lkml.org/lkml/2004/8/6/237}
[Viewed June 8, 2010]"
,annotation={
        Introduce rcu_dereference().
}
}

@unpublished{JimHouston04a
,Author="Jim Houston"
,Title="{[RFC\&PATCH] Alternative {RCU} implementation}"
,month="August"
,year="2004"
,note="Available:
\url{http://lkml.org/lkml/2004/8/30/87}
[Viewed February 17, 2005]"
,annotation={
        Uses active code in rcu_read_lock() and rcu_read_unlock() to
        make RCU happen, allowing RCU to function on CPUs that do not
        receive a scheduling-clock interrupt.
}
}

@unpublished{TomHart04a
,Author="Thomas E. Hart"
,Title="Master's Thesis: Applying Lock-free Techniques to the {Linux} Kernel"
,month="October"
,year="2004"
,note="Available:
\url{http://www.cs.toronto.edu/~tomhart/masters_thesis.html}
[Viewed October 15, 2004]"
,annotation={
        Proposes comparing RCU to lock-free methods for the Linux kernel.
}
}

@unpublished{Vaddagiri04a
,Author="Srivatsa Vaddagiri"
,Title="Subject: [RFC] Use RCU for tcp\_ehash lookup"
,month="October"
,year="2004"
,note="Available:
\url{http://marc.theaimsgroup.com/?t=109395731700004&r=1&w=2}
[Viewed October 18, 2004]"
,annotation={
        Srivatsa's RCU patch for tcp_ehash lookup.
}
}

@unpublished{Thirumalai04a
,Author="Ravikiran Thirumalai"
,Title="Subject: [patchset] Lockfree fd lookup 0 of 5"
,month="October"
,year="2004"
,note="Available:
\url{http://marc.theaimsgroup.com/?t=109144217400003&r=1&w=2}
[Viewed October 18, 2004]"
,annotation={
        Ravikiran's lockfree FD patch.
}
}

@unpublished{Thirumalai04b
,Author="Ravikiran Thirumalai"
,Title="Subject: Re: [patchset] Lockfree fd lookup 0 of 5"
,month="October"
,year="2004"
,note="Available:
\url{http://marc.theaimsgroup.com/?l=linux-kernel&m=109152521410459&w=2}
[Viewed October 18, 2004]"
,annotation={
        Ravikiran's lockfree FD patch.
}
}

@unpublished{PaulEMcKenney2004rcu:assign:pointer
,Author="Paul E. McKenney"
,Title="{[PATCH 1/3] RCU: \url{rcu_assign_pointer()} removal of memory barriers}"
,month="October"
,year="2004"
,note="Available:
\url{http://lkml.org/lkml/2004/10/23/241}
[Viewed June 8, 2010]"
,annotation={
        Introduce rcu_assign_pointer().
}
}

@unpublished{JamesMorris04a
,Author="James Morris"
,Title="{[PATCH 2/3] SELinux} scalability - convert {AVC} to {RCU}"
,day="15"
,month="November"
,year="2004"
,note="\url{http://marc.theaimsgroup.com/?l=linux-kernel&m=110054979416004&w=2}"
,annotation={
        James Morris posts Kaigai Kohei's patch to LKML.
        [Viewed December 10, 2004]
        Kaigai's patch is at https://lkml.org/lkml/2004/9/27/52
}
}

@unpublished{JamesMorris04b
,Author="James Morris"
,Title="Recent Developments in {SELinux} Kernel Performance"
,month="December"
,year="2004"
,note="Available:
\url{http://www.livejournal.com/users/james_morris/2153.html}
[Viewed December 10, 2004]"
,annotation={
        RCU helps SELinux performance.  ;-)  Made LWN.
}
}

@unpublished{PaulMcKenney2005RCUSemantics
,Author="Paul E. McKenney and Jonathan Walpole"
,Title="{RCU} Semantics: A First Attempt"
,month="January"
,year="2005"
,day="30"
,note="Available:
\url{http://www.rdrop.com/users/paulmck/RCU/rcu-semantics.2005.01.30a.pdf}
[Viewed December 6, 2009]"
,annotation={
        Early derivation of RCU semantics.
}
}

@unpublished{PaulMcKenney2005e
,Author="Paul E. McKenney"
,Title="Real-Time Preemption and {RCU}"
,month="March"
,year="2005"
,day="17"
,note="Available:
\url{http://lkml.org/lkml/2005/3/17/199}
[Viewed September 5, 2005]"
,annotation={
        First posting showing how RCU can be safely adapted for
        preemptable RCU read side critical sections.
}
}

@unpublished{EsbenNeilsen2005a
,Author="Esben Neilsen"
,Title="Re: Real-Time Preemption and {RCU}"
,month="March"
,year="2005"
,day="18"
,note="Available:
\url{http://lkml.org/lkml/2005/3/18/122}
[Viewed March 30, 2006]"
,annotation={
        Esben Neilsen suggests read-side suppression of grace-period
        processing for crude-but-workable realtime RCU.  The downside
        is indefinite grace periods...  But this is OK for experimentation
        and testing.
}
}

@unpublished{TomHart05a
,Author="Thomas E. Hart and Paul E. McKenney and Angela Demke Brown"
,Title="Efficient Memory Reclamation is Necessary for Fast Lock-Free
Data Structures"
,month="March"
,year="2005"
,note="Available:
\url{ftp://ftp.cs.toronto.edu/csrg-technical-reports/515/}
[Viewed March 4, 2005]"
,annotation={
        Comparison of RCU, QBSR, and EBSR.  RCU wins for read-mostly
        workloads.  ;-)
}
}

@unpublished{JonCorbet2005DeprecateSyncKernel
,Author="Jonathan Corbet"
,Title="API change: synchronize_kernel() deprecated"
,month="May"
,day="3"
,year="2005"
,note="Available:
\url{http://lwn.net/Articles/134484/}
[Viewed May 3, 2005]"
,annotation={
        Jon Corbet describes deprecation of synchronize_kernel()
        in favor of synchronize_rcu() and synchronize_sched().
}
}

@unpublished{PaulMcKenney05a
,Author="Paul E. McKenney"
,Title="{[RFC]} {RCU} and {CONFIG\_PREEMPT\_RT} progress"
,month="May"
,year="2005"
,note="Available:
\url{http://lkml.org/lkml/2005/5/9/185}
[Viewed May 13, 2005]"
,annotation={
        First publication of working lock-based deferred free patches
        for the CONFIG_PREEMPT_RT environment.
}
}

@conference{PaulMcKenney05b
,Author="Paul E. McKenney and Dipankar Sarma"
,Title="Towards Hard Realtime Response from the {Linux} Kernel on {SMP} Hardware"
,Booktitle="linux.conf.au 2005"
,month="April"
,year="2005"
,address="Canberra, Australia"
,note="Available:
\url{http://www.rdrop.com/users/paulmck/RCU/realtimeRCU.2005.04.23a.pdf}
[Viewed May 13, 2005]"
,annotation={
        Realtime turns into making RCU yet more realtime friendly.
        http://lca2005.linux.org.au/Papers/Paul%20McKenney/Towards%20Hard%20Realtime%20Response%20from%20the%20Linux%20Kernel/LKS.2005.04.22a.pdf
}
}

@unpublished{PaulEMcKenneyHomePage
,Author="Paul E. McKenney"
,Title="{Paul} {E.} {McKenney}"
,month="May"
,year="2005"
,note="Available:
\url{http://www.rdrop.com/users/paulmck/}
[Viewed May 25, 2005]"
,annotation={
        Paul McKenney's home page.
}
}

@unpublished{PaulEMcKenneyRCUPage
,Author="Paul E. McKenney"
,Title="Read-Copy Update {(RCU)}"
,month="May"
,year="2005"
,note="Available:
\url{http://www.rdrop.com/users/paulmck/RCU}
[Viewed May 25, 2005]"
,annotation={
        Paul McKenney's RCU page.
}
}

@unpublished{JosephSeigh2005a
,Author="Joseph Seigh"
,Title="{RCU}+{SMR} (hazard pointers)"
,month="July"
,year="2005"
,note="Personal communication"
,annotation={
        Joe Seigh announcing his atomic-ptr-plus project.
        http://sourceforge.net/projects/atomic-ptr-plus/
}
}

@unpublished{JosephSeigh2005b
,Author="Joseph Seigh"
,Title="Lock-free synchronization primitives"
,month="July"
,day="6"
,year="2005"
,note="Available:
\url{http://sourceforge.net/projects/atomic-ptr-plus/}
[Viewed August 8, 2005]"
,annotation={
        Joe Seigh's atomic-ptr-plus project.
}
}

@unpublished{PaulMcKenney2005c
,Author="Paul E.McKenney"
,Title="{[RFC,PATCH] RCU} and {CONFIG\_PREEMPT\_RT} sane patch"
,month="August"
,day="1"
,year="2005"
,note="Available:
\url{http://lkml.org/lkml/2005/8/1/155}
[Viewed March 14, 2006]"
,annotation={
        First operating counter-based realtime RCU patch posted to LKML.
}
}

@unpublished{PaulMcKenney2005d
,Author="Paul E. McKenney"
,Title="Re: [Fwd: Re: [patch] Real-Time Preemption, -RT-2.6.13-rc4-V0.7.52-01]"
,month="August"
,day="8"
,year="2005"
,note="Available:
\url{http://lkml.org/lkml/2005/8/8/108}
[Viewed March 14, 2006]"
,annotation={
        First operating counter-based realtime RCU patch posted to LKML,
        but fixed so that various unusual combinations of configuration
        parameters all function properly.
}
}

@unpublished{PaulMcKenney2005rcutorture
,Author="Paul E. McKenney"
,Title="{[PATCH]} {RCU} torture testing"
,month="October"
,day="1"
,year="2005"
,note="Available:
\url{http://lkml.org/lkml/2005/10/1/70}
[Viewed March 14, 2006]"
,annotation={
        First rcutorture patch.
}
}

@unpublished{DavidSMiller2006HashedLocking
,Author="David S. Miller"
,Title="Re: [{PATCH}, {RFC}] {RCU} : {OOM} avoidance and lower latency"
,month="January"
,day="6"
,year="2006"
,note="Available:
\url{https://lkml.org/lkml/2006/1/7/22}
[Viewed February 29, 2012]"
,annotation={
        David Miller's view on hashed arrays of locks: used to really
        like it, but time he saw an opportunity for this technique,
        something else always proved superior.  Partitioning or RCU.  ;-)
}
}

@conference{ThomasEHart2006a
,Author="Thomas E. Hart and Paul E. McKenney and Angela Demke Brown"
,Title="Making Lockless Synchronization Fast: Performance Implications
of Memory Reclamation"
,Booktitle="20\textsuperscript{th} {IEEE} International Parallel and
Distributed Processing Symposium"
,month="April"
,year="2006"
,day="25-29"
,address="Rhodes, Greece"
,note="Available:
\url{http://www.rdrop.com/users/paulmck/RCU/hart_ipdps06.pdf}
[Viewed April 28, 2008]"
,annotation={
        Compares QSBR, HPBR, EBR, and lock-free reference counting.
        http://www.cs.toronto.edu/~tomhart/perflab/ipdps06.tgz
}
}

@unpublished{NickPiggin2006radixtree
,Author="Nick Piggin"
,Title="[patch 3/3] radix-tree: {RCU} lockless readside"
,month="June"
,day="20"
,year="2006"
,note="Available:
\url{http://lkml.org/lkml/2006/6/20/238}
[Viewed March 25, 2008]"
,annotation={
        RCU-protected radix tree.
}
}

@Conference{PaulEMcKenney2006b
,Author="Paul E. McKenney and Dipankar Sarma and Ingo Molnar and
Suparna Bhattacharya"
,Title="Extending {RCU} for Realtime and Embedded Workloads"
,Booktitle="{Ottawa Linux Symposium}"
,Month="July"
,Year="2006"
,pages="v2 123-138"
,note="Available:
\url{http://www.linuxsymposium.org/2006/view_abstract.php?content_key=184}
\url{http://www.rdrop.com/users/paulmck/RCU/OLSrtRCU.2006.08.11a.pdf}
[Viewed January 1, 2007]"
,annotation={
        Described how to improve the -rt implementation of realtime RCU.
}
}

@unpublished{WikipediaRCU
,Author="Paul E. McKenney and Chris Purcell and Algae and Ben Schumin and
Gaius Cornelius and Qwertyus and Neil Conway and Sbw and Blainster and
Canis Rufus and Zoicon5 and Anome and Hal Eisen"
,Title="Read-Copy Update"
,month="July"
,day="8"
,year="2006"
,note="\url{https://en.wikipedia.org/wiki/Read-copy-update}"
,annotation={
        Wikipedia RCU page as of July 8 2006.
        [Viewed August 21, 2006]
}
}

@Conference{NickPiggin2006LocklessPageCache
,Author="Nick Piggin"
,Title="A Lockless Pagecache in Linux---Introduction, Progress, Performance"
,Booktitle="{Ottawa Linux Symposium}"
,Month="July"
,Year="2006"
,pages="v2 249-254"
,note="Available:
\url{http://www.linuxsymposium.org/2006/view_abstract.php?content_key=184}
[Viewed January 11, 2009]"
,annotation={
        Uses RCU-protected radix tree for a lockless page cache.
}
}

@unpublished{PaulEMcKenney2006c
,Author="Paul E. McKenney"
,Title="Sleepable {RCU}"
,month="October"
,day="9"
,year="2006"
,note="Available:
\url{http://lwn.net/Articles/202847/}
Revised:
\url{http://www.rdrop.com/users/paulmck/RCU/srcu.2007.01.14a.pdf}
[Viewed August 21, 2006]"
,annotation={
        LWN article introducing SRCU.
}
}

@unpublished{RobertOlsson2006a
,Author="Robert Olsson and Stefan Nilsson"
,Title="{TRASH}: A dynamic {LC}-trie and hash data structure"
,month="August"
,day="18"
,year="2006"
,note="\url{http://www.nada.kth.se/~snilsson/publications/TRASH/trash.pdf}"
,annotation={
        RCU-protected dynamic trie-hash combination.
        [Viewed March 4, 2011]
}
}

@unpublished{ChristophHellwig2006RCU2SRCU
,Author="Christoph Hellwig"
,Title="Re: {[-mm PATCH 1/4]} {RCU}: split classic rcu"
,month="September"
,day="28"
,year="2006"
,note="Available:
\url{http://lkml.org/lkml/2006/9/28/160}
[Viewed March 27, 2008]"
}

@unpublished{PaulEMcKenneyRCUusagePage
,Author="Paul E. McKenney"
,Title="{RCU} {Linux} Usage"
,month="October"
,year="2006"
,note="Available:
\url{http://www.rdrop.com/users/paulmck/RCU/linuxusage.html}
[Viewed January 14, 2007]"
,annotation={
        Paul McKenney's RCU page showing graphs plotting Linux-kernel
        usage of RCU.
}
}

@unpublished{PaulEMcKenneyRCUusageRawDataPage
,Author="Paul E. McKenney"
,Title="Read-Copy Update {(RCU)} Usage in {Linux} Kernel"
,month="October"
,year="2006"
,note="Available:
\url{http://www.rdrop.com/users/paulmck/RCU/linuxusage/rculocktab.html}
[Viewed January 14, 2007]"
,annotation={
        Paul McKenney's RCU page showing Linux usage of RCU in tabular
        form, with links to corresponding cscope databases.
}
}

@unpublished{GauthamShenoy2006RCUrwlock
,Author="Gautham R. Shenoy"
,Title="[PATCH 4/5] lock\_cpu\_hotplug: Redesign - Lightweight implementation of lock\_cpu\_hotplug"
,month="October"
,year="2006"
,day=26
,note="Available:
\url{http://lkml.org/lkml/2006/10/26/73}
[Viewed January 26, 2009]"
,annotation={
        RCU-based reader-writer lock that allows readers to proceed with
        no memory barriers or atomic instruction in absence of writers.
        If writer do show up, readers must of course wait as required by
        the semantics of reader-writer locking.  This is a recursive
        lock.
}
}

@unpublished{JensAxboe2006SlowSRCU
,Author="Jens Axboe"
,Title="Re: [patch] cpufreq: mark \url{cpufreq_tsc()} as
\url{core_initcall_sync}"
,month="November"
,year="2006"
,day=17
,note="Available:
\url{http://lkml.org/lkml/2006/11/17/56}
[Viewed May 28, 2007]"
,annotation={
        SRCU's grace periods are too slow for Jens, even after a
        factor-of-three speedup.
        Sped-up version of SRCU at http://lkml.org/lkml/2006/11/17/359.
}
}

@unpublished{OlegNesterov2006QRCU
,Author="Oleg Nesterov"
,Title="Re: [patch] cpufreq: mark {\tt cpufreq\_tsc()} as
{\tt core\_initcall\_sync}"
,month="November"
,year="2006"
,day=19
,note="Available:
\url{http://lkml.org/lkml/2006/11/19/69}
[Viewed May 28, 2007]"
,annotation={
        First cut of QRCU.  Expanded/corrected versions followed.
        Used to be OlegNesterov2007QRCU, now time-corrected.
}
}

@unpublished{OlegNesterov2006aQRCU
,Author="Oleg Nesterov"
,Title="Re: [RFC, PATCH 1/2] qrcu: {"quick"} srcu implementation"
,month="November"
,year="2006"
,day=30
,note="Available:
\url{http://lkml.org/lkml/2006/11/29/330}
[Viewed November 26, 2008]"
,annotation={
        Expanded/corrected version of QRCU.
        Used to be OlegNesterov2007aQRCU, now time-corrected.
}
}

@unpublished{EvgeniyPolyakov2006RCUslowdown
,Author="Evgeniy Polyakov"
,Title="Badness in postponing work"
,month="December"
,year="2006"
,day=05
,note="Available:
\url{http://www.ioremap.net/node/41}
[Viewed October 28, 2008]"
,annotation={
        Using RCU as a pure delay leads to a 2.5x slowdown in skbs in
        the Linux kernel.
}
}

@inproceedings{ChrisMatthews2006ClusteredObjectsRCU
,author = {Matthews, Chris and Coady, Yvonne and Appavoo, Jonathan}
,title = {Portability events: a programming model for scalable system infrastructures}
,booktitle = {PLOS '06: Proceedings of the 3rd workshop on Programming languages and operating systems}
,year = {2006}
,isbn = {1-59593-577-0}
,pages = {11}
,location = {San Jose, California}
,doi = {http://doi.acm.org/10.1145/1215995.1216006}
,publisher = {ACM}
,address = {New York, NY, USA}
,annotation={
        Uses K42's RCU-like functionality to manage clustered-object
        lifetimes.
}
}

@article{DilmaDaSilva2006K42
,author = {Silva, Dilma Da and Krieger, Orran and Wisniewski, Robert W. and Waterland, Amos and Tam, David and Baumann, Andrew}
,title = {K42: an infrastructure for operating system research}
,journal = {SIGOPS Oper. Syst. Rev.}
,volume = {40}
,number = {2}
,year = {2006}
,issn = {0163-5980}
,pages = {34--42}
,doi = {http://doi.acm.org/10.1145/1131322.1131333}
,publisher = {ACM}
,address = {New York, NY, USA}
,annotation={
        Describes relationship of K42 generations to RCU.
}
}

# CoreyMinyard2007list_splice_rcu
@unpublished{CoreyMinyard2007list:splice:rcu
,Author="Corey Minyard and Paul E. McKenney"
,Title="{[PATCH]} add an {RCU} version of list splicing"
,month="January"
,year="2007"
,day=3
,note="Available:
\url{http://lkml.org/lkml/2007/1/3/112}
[Viewed May 28, 2007]"
,annotation={
        Patch for list_splice_rcu().
}
}

@unpublished{PaulEMcKenney2007rcubarrier
,Author="Paul E. McKenney"
,Title="{RCU} and Unloadable Modules"
,month="January"
,day="14"
,year="2007"
,note="Available:
\url{http://lwn.net/Articles/217484/}
[Viewed November 22, 2007]"
,annotation={
        LWN article introducing the rcu_barrier() primitive.
}
}

@unpublished{PeterZijlstra2007SyncBarrier
,Author="Peter Zijlstra and Ingo Molnar"
,Title="{[PATCH 3/7]} barrier: a scalable synchonisation barrier"
,month="January"
,year="2007"
,day=28
,note="Available:
\url{http://lkml.org/lkml/2007/1/28/34}
[Viewed March 27, 2008]"
,annotation={
        RCU-like implementation for frequent updaters and rare readers(!).
        Subsumed into QRCU.  Maybe...
}
}

@unpublished{PaulEMcKenney2007BoostRCU
,Author="Paul E. McKenney"
,Title="Priority-Boosting {RCU} Read-Side Critical Sections"
,month="February"
,day="5"
,year="2007"
,note="\url{http://lwn.net/Articles/220677/}"
,annotation={
        LWN article introducing RCU priority boosting.
        Revised:
        http://www.rdrop.com/users/paulmck/RCU/RCUbooststate.2007.04.16a.pdf
        [Viewed September 7, 2007]
}
}

@unpublished{PaulMcKenney2007QRCUpatch
,Author="Paul E. McKenney"
,Title="{[PATCH]} {QRCU} with lockless fastpath"
,month="February"
,year="2007"
,day=24
,note="Available:
\url{http://lkml.org/lkml/2007/2/25/18}
[Viewed March 27, 2008]"
,annotation={
        Patch for QRCU supplying lock-free fast path.
}
}

@article{JonathanAppavoo2007K42RCU
,author = {Appavoo, Jonathan and Silva, Dilma Da and Krieger, Orran and Auslander, Marc and Ostrowski, Michal and Rosenburg, Bryan and Waterland, Amos and Wisniewski, Robert W. and Xenidis, Jimi and Stumm, Michael and Soares, Livio}
,title = {Experience distributing objects in an SMMP OS}
,journal = {ACM Trans. Comput. Syst.}
,volume = {25}
,number = {3}
,year = {2007}
,issn = {0734-2071}
,pages = {6/1--6/52}
,doi = {http://doi.acm.org/10.1145/1275517.1275518}
,publisher = {ACM}
,address = {New York, NY, USA}
,annotation={
        Role of RCU in K42.
}
}

@conference{RobertOlsson2007Trash
,Author="Robert Olsson and Stefan Nilsson"
,Title="{TRASH}: A dynamic {LC}-trie and hash data structure"
,booktitle="Workshop on High Performance Switching and Routing (HPSR'07)"
,month="May"
,year="2007"
,note="Available:
\url{http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=4281239}
[Viewed October 1, 2010]"
,annotation={
        RCU-protected dynamic trie-hash combination.
}
}

@conference{PeterZijlstra2007ConcurrentPagecacheRCU
,Author="Peter Zijlstra"
,Title="Concurrent Pagecache"
,Booktitle="Linux Symposium"
,month="June"
,year="2007"
,address="Ottawa, Canada"
,note="Available:
\url{http://ols.108.redhat.com/2007/Reprints/zijlstra-Reprint.pdf}
[Viewed April 14, 2008]"
,annotation={
        Page-cache modifications permitting RCU readers and concurrent
        updates.
}
}

@unpublished{PaulEMcKenney2007whatisRCU
,Author="Paul E. McKenney"
,Title="What is {RCU}?"
,year="2007"
,month="07"
,note="Available:
\url{http://www.rdrop.com/users/paulmck/RCU/whatisRCU.html}
[Viewed July 6, 2007]"
,annotation={
        Describes RCU in Linux kernel.
}
}

@unpublished{PaulEMcKenney2007QRCUspin
,Author="Paul E. McKenney"
,Title="Using {Promela} and {Spin} to verify parallel algorithms"
,month="August"
,day="1"
,year="2007"
,note="Available:
\url{http://lwn.net/Articles/243851/}
[Viewed September 8, 2007]"
,annotation={
        LWN article describing Promela and spin, and also using Oleg
        Nesterov's QRCU as an example (with Paul McKenney's fastpath).
        Merged patch at: http://lkml.org/lkml/2007/2/25/18
}
}

@unpublished{PaulEMcKenney2007WG21DDOatomics
,Author="Paul E. McKenney and Hans-J. Boehm and Lawrence Crowl"
,Title="C++ Data-Dependency Ordering: Atomics and Memory Model"
,month="August"
,day="3"
,year="2007"
,note="Available:
\url{http://open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2664.htm}
[Viewed December 7, 2009]"
,annotation={
        RCU for C++, parts 1 and 2.
}
}

@unpublished{PaulEMcKenney2007WG21DDOannotation
,Author="Paul E. McKenney and Lawrence Crowl"
,Title="C++ Data-Dependency Ordering: Function Annotation"
,month="September"
,day="18"
,year="2008"
,note="Available:
\url{http://open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2782.htm}
[Viewed December 7, 2009]"
,annotation={
        RCU for C++, part 2, updated many times.
}
}

@unpublished{PaulEMcKenney2007PreemptibleRCUPatch
,Author="Paul E. McKenney"
,Title="[PATCH RFC 0/9] {RCU}: Preemptible {RCU}"
,month="September"
,day="10"
,year="2007"
,note="Available:
\url{http://lkml.org/lkml/2007/9/10/213}
[Viewed October 25, 2007]"
,annotation={
        Final patch for preemptable RCU to -rt.  (Later patches were
        to mainline, eventually incorporated.)
}
}

@unpublished{PaulEMcKenney2007PreemptibleRCU
,Author="Paul E. McKenney"
,Title="The design of preemptible read-copy-update"
,month="October"
,day="8"
,year="2007"
,note="Available:
\url{http://lwn.net/Articles/253651/}
[Viewed October 25, 2007]"
,annotation={
        LWN article describing the design of preemptible RCU.
}
}

@article{ThomasEHart2007a
,Author="Thomas E. Hart and Paul E. McKenney and Angela Demke Brown and Jonathan Walpole"
,Title="Performance of memory reclamation for lockless synchronization"
,journal="J. Parallel Distrib. Comput."
,volume={67}
,number="12"
,year="2007"
,issn="0743-7315"
,pages="1270--1285"
,doi="http://dx.doi.org/10.1016/j.jpdc.2007.04.010"
,publisher="Academic Press, Inc."
,address="Orlando, FL, USA"
,annotation={
        Compares QSBR, HPBR, EBR, and lock-free reference counting.
        Journal version of ThomasEHart2006a.
}
}

# MathieuDesnoyers2007call_rcu_schedNeeded
@unpublished{MathieuDesnoyers2007call:rcu:schedNeeded
,Author="Mathieu Desnoyers"
,Title="Re: [patch 1/2] {Linux} Kernel Markers - Support Multiple Probes"
,month="December"
,day="20"
,year="2007"
,note="Available:
\url{http://lkml.org/lkml/2007/12/20/244}
[Viewed March 27, 2008]"
,annotation={
        Request for call_rcu_sched() and rcu_barrier_sched().
}
}


########################################################################
#
#       "What is RCU?" LWN series.
#
#       http://lwn.net/Articles/262464/ (What is RCU, Fundamentally?)
#       http://lwn.net/Articles/263130/ (What is RCU's Usage?)
#       http://lwn.net/Articles/264090/ (What is RCU's API?)

@unpublished{PaulEMcKenney2007WhatIsRCUFundamentally
,Author="Paul E. McKenney and Jonathan Walpole"
,Title="What is {RCU}, Fundamentally?"
,month="December"
,day="17"
,year="2007"
,note="Available:
\url{http://lwn.net/Articles/262464/}
[Viewed December 27, 2007]"
,annotation={
        Lays out the three basic components of RCU: (1) publish-subscribe,
        (2) wait for pre-existing readers to complete, and (2) maintain
        multiple versions.
}
}

@unpublished{PaulEMcKenney2008WhatIsRCUUsage
,Author="Paul E. McKenney"
,Title="What is {RCU}? Part 2: Usage"
,month="January"
,day="4"
,year="2008"
,note="Available:
\url{http://lwn.net/Articles/263130/}
[Viewed January 4, 2008]"
,annotation={
        Lays out six uses of RCU:
        1. RCU is a Reader-Writer Lock Replacement
        2. RCU is a Restricted Reference-Counting Mechanism
        3. RCU is a Bulk Reference-Counting Mechanism
        4. RCU is a Poor Man's Garbage Collector
        5. RCU is a Way of Providing Existence Guarantees
        6. RCU is a Way of Waiting for Things to Finish
}
}

@unpublished{PaulEMcKenney2008WhatIsRCUAPI
,Author="Paul E. McKenney"
,Title="{RCU} part 3: the {RCU} {API}"
,month="January"
,day="17"
,year="2008"
,note="Available:
\url{http://lwn.net/Articles/264090/}
[Viewed January 10, 2008]"
,annotation={
        Gives an overview of the Linux-kernel RCU API and a brief annotated RCU
        bibliography.
}
}

#
#       "What is RCU?" LWN series.
#
########################################################################


@unpublished{SteveRostedt2008dyntickRCUpatch
,Author="Steven Rostedt and Paul E. McKenney"
,Title="{[PATCH]} add support for dynamic ticks and preempt rcu"
,month="January"
,day="29"
,year="2008"
,note="Available:
\url{http://lkml.org/lkml/2008/1/29/208}
[Viewed March 27, 2008]"
,annotation={
        Patch that prevents preemptible RCU from unnecessarily waking
        up dynticks-idle CPUs.
}
}

@unpublished{PaulEMcKenney2008LKMLDependencyOrdering
,Author="Paul E. McKenney"
,Title="Re: [PATCH 02/22 -v7] Add basic support for gcc profiler instrumentation"
,month="February"
,day="1"
,year="2008"
,note="Available:
\url{http://lkml.org/lkml/2008/2/2/255}
[Viewed October 18, 2008]"
,annotation={
        Explanation of compilers violating dependency ordering.
}
}

@Conference{PaulEMcKenney2008Beijing
,Author="Paul E. McKenney"
,Title="Introducing Technology Into {Linux} Or:
Introducing your technology Into {Linux} will require introducing a
lot of {Linux} into your technology!!!"
,Booktitle="2008 Linux Developer Symposium - China"
,Publisher="OSS China"
,Month="February"
,Year="2008"
,Address="Beijing, China"
,note="Available:
\url{http://www.rdrop.com/users/paulmck/RCU/TechIntroLinux.2008.02.19a.pdf}
[Viewed August 12, 2008]"
}

@unpublished{PaulEMcKenney2008dynticksRCU
,Author="Paul E. McKenney and Steven Rostedt"
,Title="Integrating and Validating dynticks and Preemptable RCU"
,month="April"
,day="24"
,year="2008"
,note="Available:
\url{http://lwn.net/Articles/279077/}
[Viewed April 24, 2008]"
,annotation={
        Describes use of Promela and Spin to validate (and fix!) the
        dynticks/RCU interface.
}
}

@article{DinakarGuniguntala2008IBMSysJ
,author="D. Guniguntala and P. E. McKenney and J. Triplett and J. Walpole"
,title="The read-copy-update mechanism for supporting real-time applications on shared-memory multiprocessor systems with {Linux}"
,Year="2008"
,Month="May"
,journal="IBM Systems Journal"
,volume="47"
,number="2"
,pages="221-236"
,annotation={
        RCU, realtime RCU, sleepable RCU, performance.
        http://www.research.ibm.com/journal/sj/472/guniguntala.pdf
        [Viewed April 24, 2008]
}
}

@unpublished{LaiJiangshan2008NewClassicAlgorithm
,Author="Lai Jiangshan"
,Title="[{RFC}][{PATCH}] rcu classic: new algorithm for callbacks-processing"
,month="June"
,day="3"
,year="2008"
,note="Available:
\url{http://lkml.org/lkml/2008/6/2/539}
[Viewed December 10, 2008]"
,annotation={
        Updated RCU classic algorithm.  Introduced multi-tailed list
        for RCU callbacks and also pulling common code into
        __call_rcu().
}
}

@article{PaulEMcKenney2008RCUOSR
,author="Paul E. McKenney and Jonathan Walpole"
,title="Introducing technology into the {Linux} kernel: a case study"
,Year="2008"
,journal="SIGOPS Oper. Syst. Rev."
,volume="42"
,number="5"
,pages="4--17"
,issn="0163-5980"
,doi={http://doi.acm.org/10.1145/1400097.1400099}
,publisher="ACM"
,address="New York, NY, USA"
,annotation={
        Linux changed RCU to a far greater degree than RCU has changed Linux.
        http://portal.acm.org/citation.cfm?doid=1400097.1400099
}
}

@unpublished{ManfredSpraul2008StateMachineRCU
,Author="Manfred Spraul"
,Title="[{RFC}, {PATCH}] state machine based rcu"
,month="August"
,day="21"
,year="2008"
,note="Available:
\url{http://lkml.org/lkml/2008/8/21/336}
[Viewed December 8, 2008]"
,annotation={
        State-based RCU.  One key thing that this patch does is to
        separate the dynticks handling of NMIs and IRQs.
}
}

@unpublished{ManfredSpraul2008dyntickIRQNMI
,Author="Manfred Spraul"
,Title="Re: [{RFC}, {PATCH}] v4 scalable classic {RCU} implementation"
,month="September"
,day="6"
,year="2008"
,note="Available:
\url{http://lkml.org/lkml/2008/9/6/86}
[Viewed December 8, 2008]"
,annotation={
        Manfred notes a fix required to my attempt to separate irq
        and NMI processing for hierarchical RCU's dynticks interface.
}
}

# Was PaulEMcKenney2011cyclicRCU
@techreport{PaulEMcKenney2008cyclicRCU
,author="Paul E. McKenney"
,title="Efficient Support of Consistent Cyclic Search With Read-Copy Update"
,institution="US Patent and Trademark Office"
,address="Washington, DC"
,year="2008"
,number="US Patent 7,426,511"
,month="September"
,pages="23"
,annotation={
        Maintains an additional level of indirection to allow
        readers to confine themselves to the desired snapshot of the
        data structure.  Only permits one update at a time.
}
}

@unpublished{PaulEMcKenney2008HierarchicalRCU
,Author="Paul E. McKenney"
,Title="Hierarchical {RCU}"
,month="November"
,day="3"
,year="2008"
,note="\url{http://lwn.net/Articles/305782/}"
,annotation={
        RCU with combining-tree-based grace-period detection,
        permitting it to handle thousands of CPUs.
        [Viewed November 6, 2008]
}
}

@unpublished{PaulEMcKenney2009BloatwatchRCU
,Author="Paul E. McKenney"
,Title="Re: [PATCH fyi] RCU: the bloatwatch edition"
,month="January"
,day="14"
,year="2009"
,note="Available:
\url{http://lkml.org/lkml/2009/1/14/449}
[Viewed January 15, 2009]"
,annotation={
        Small-footprint implementation of RCU for uniprocessor
        embedded applications -- and also for exposition purposes.
}
}

@conference{PaulEMcKenney2009MaliciousURCU
,Author="Paul E. McKenney"
,Title="Using a Malicious User-Level {RCU} to Torture {RCU}-Based Algorithms"
,Booktitle="linux.conf.au 2009"
,month="January"
,year="2009"
,address="Hobart, Australia"
,note="Available:
\url{http://www.rdrop.com/users/paulmck/RCU/urcutorture.2009.01.22a.pdf}
[Viewed February 2, 2009]"
,annotation={
        Realtime RCU and torture-testing RCU uses.
}
}

@unpublished{MathieuDesnoyers2009URCU
,Author="Mathieu Desnoyers"
,Title="[{RFC} git tree] Userspace {RCU} (urcu) for {Linux}"
,month="February"
,day="5"
,year="2009"
,note="\url{http://lttng.org/urcu}"
,annotation={
        Mathieu Desnoyers's user-space RCU implementation.
        git://lttng.org/userspace-rcu.git
        http://lttng.org/cgi-bin/gitweb.cgi?p=userspace-rcu.git
        http://lttng.org/urcu
        http://lkml.org/lkml/2009/2/5/572
}
}

@unpublished{PaulEMcKenney2009LWNBloatWatchRCU
,Author="Paul E. McKenney"
,Title="{RCU}: The {Bloatwatch} Edition"
,month="March"
,day="17"
,year="2009"
,note="Available:
\url{http://lwn.net/Articles/323929/}
[Viewed March 20, 2009]"
,annotation={
        Uniprocessor assumptions allow simplified RCU implementation.
}
}

@unpublished{EvgeniyPolyakov2009EllipticsNetwork
,Author="Evgeniy Polyakov"
,Title="The Elliptics Network"
,month="April"
,day="17"
,year="2009"
,note="Available:
\url{http://www.ioremap.net/projects/elliptics}
[Viewed April 30, 2009]"
,annotation={
        Distributed hash table with transactions, using elliptic
        hash functions to distribute data.
}
}

@unpublished{PaulEMcKenney2009expeditedRCU
,Author="Paul E. McKenney"
,Title="[{PATCH} -tip 0/3] expedited 'big hammer' {RCU} grace periods"
,month="June"
,day="25"
,year="2009"
,note="Available:
\url{http://lkml.org/lkml/2009/6/25/306}
[Viewed August 16, 2009]"
,annotation={
        First posting of expedited RCU to be accepted into -tip.
}
}

@unpublished{PaulEMcKenney2009fastRTRCU
,Author="Paul E. McKenney"
,Title="[{PATCH} {RFC} -tip 0/4] {RCU} cleanups and simplified preemptable {RCU}"
,month="July"
,day="23"
,year="2009"
,note="Available:
\url{http://lkml.org/lkml/2009/7/23/294}
[Viewed August 15, 2009]"
,annotation={
        First posting of simple and fast preemptable RCU.
}
}

@unpublished{JoshTriplett2009RPHash
,Author="Josh Triplett"
,Title="Scalable concurrent hash tables via relativistic programming"
,month="September"
,year="2009"
,note="Linux Plumbers Conference presentation"
,annotation={
        RP fun with hash tables.
        Superseded by JoshTriplett2010RPHash
}
}

@phdthesis{MathieuDesnoyersPhD
, title  = "Low-Impact Operating System Tracing"
, author = "Mathieu Desnoyers"
, school = "Ecole Polytechnique de Montr\'{e}al"
, month  = "December"
, year   = 2009
,note="Available:
\url{http://www.lttng.org/pub/thesis/desnoyers-dissertation-2009-12.pdf}
[Viewed December 9, 2009]"
,annotation={
        Chapter 6 (page 97) covers user-level RCU.
}
}

@unpublished{RelativisticProgrammingWiki
,Author="Josh Triplett and Paul E. McKenney and Jonathan Walpole"
,Title="Relativistic Programming"
,month="September"
,year="2009"
,note="Available:
\url{http://wiki.cs.pdx.edu/rp/}
[Viewed December 9, 2009]"
,annotation={
        Main Relativistic Programming Wiki.
}
}

@conference{PaulEMcKenney2009DeterministicRCU
,Author="Paul E. McKenney"
,Title="Deterministic Synchronization in Multicore Systems: the Role of {RCU}"
,Booktitle="Eleventh Real Time Linux Workshop"
,month="September"
,year="2009"
,address="Dresden, Germany"
,note="Available:
\url{http://www.rdrop.com/users/paulmck/realtime/paper/DetSyncRCU.2009.08.18a.pdf}
[Viewed January 14, 2009]"
}

@unpublished{PaulEMcKenney2009HuntingHeisenbugs
,Author="Paul E. McKenney"
,Title="Hunting Heisenbugs"
,month="November"
,year="2009"
,day="1"
,note="Available:
\url{http://paulmck.livejournal.com/14639.html}
[Viewed June 4, 2010]"
,annotation={
        Day-one bug in Tree RCU that took forever to track down.
}
}

@unpublished{MathieuDesnoyers2009defer:rcu
,Author="Mathieu Desnoyers"
,Title="Kernel RCU: shrink the size of the struct rcu\_head"
,month="December"
,year="2009"
,note="Available:
\url{http://lkml.org/lkml/2009/10/18/129}
[Viewed December 29, 2009]"
,annotation={
        Mathieu proposed defer_rcu() with fixed-size per-thread pool
        of RCU callbacks.
}
}

@unpublished{MathieuDesnoyers2009VerifPrePub
,Author="Mathieu Desnoyers and Paul E. McKenney and Michel R. Dagenais"
,Title="Multi-Core Systems Modeling for Formal Verification of Parallel Algorithms"
,month="December"
,year="2009"
,note="Submitted to IEEE TPDS"
,annotation={
        OOMem model for Mathieu's user-level RCU mechanical proof of
        correctness.
}
}

@unpublished{MathieuDesnoyers2009URCUPrePub
,Author="Mathieu Desnoyers and Paul E. McKenney and Alan Stern and Michel R. Dagenais and Jonathan Walpole"
,Title="User-Level Implementations of Read-Copy Update"
,month="December"
,year="2010"
,url={\url{http://www.computer.org/csdl/trans/td/2012/02/ttd2012020375-abs.html}}
,annotation={
        RCU overview, desiderata, semi-formal semantics, user-level RCU
        usage scenarios, three classes of RCU implementation, wait-free
        RCU updates, RCU grace-period batching, update overhead,
        http://www.rdrop.com/users/paulmck/RCU/urcu-main-accepted.2011.08.30a.pdf
        http://www.rdrop.com/users/paulmck/RCU/urcu-supp-accepted.2011.08.30a.pdf
        Superseded by MathieuDesnoyers2012URCU.
}
}

@inproceedings{HariKannan2009DynamicAnalysisRCU
,author = {Kannan, Hari}
,title = {Ordering decoupled metadata accesses in multiprocessors}
,booktitle = {MICRO 42: Proceedings of the 42nd Annual IEEE/ACM International Symposium on Microarchitecture}
,year = {2009}
,isbn = {978-1-60558-798-1}
,pages = {381--390}
,location = {New York, New York}
,doi = {http://doi.acm.org/10.1145/1669112.1669161}
,publisher = {ACM}
,address = {New York, NY, USA}
,annotation={
        Uses RCU to protect metadata used in dynamic analysis.
}
}

@conference{PaulEMcKenney2010SimpleOptRCU
,Author="Paul E. McKenney"
,Title="Simplicity Through Optimization"
,Booktitle="linux.conf.au 2010"
,month="January"
,year="2010"
,address="Wellington, New Zealand"
,note="Available:
\url{http://www.rdrop.com/users/paulmck/RCU/SimplicityThruOptimization.2010.01.21f.pdf}
[Viewed October 10, 2010]"
,annotation={
        TREE_PREEMPT_RCU optimizations greatly simplified the old
        PREEMPT_RCU implementation.
}
}

@unpublished{PaulEMcKenney2010LockdepRCU
,Author="Paul E. McKenney"
,Title="Lockdep-{RCU}"
,month="February"
,year="2010"
,day="1"
,note="\url{https://lwn.net/Articles/371986/}"
,annotation={
        CONFIG_PROVE_RCU, or at least an early version.
        [Viewed June 4, 2010]
}
}

@unpublished{AviKivity2010KVM2RCU
,Author="Avi Kivity"
,Title="[{PATCH} 37/40] {KVM}: Bump maximum vcpu count to 64"
,month="February"
,year="2010"
,note="Available:
\url{http://www.mail-archive.com/kvm@vger.kernel.org/msg28640.html}
[Viewed March 20, 2010]"
,annotation={
        Use of RCU permits KVM to increase the size of guest OSes from
        16 CPUs to 64 CPUs.
}
}

@unpublished{HerbertXu2010RCUResizeHash
,Author="Herbert Xu"
,Title="bridge: Add core IGMP snooping support"
,month="February"
,year="2010"
,note="Available:
\url{http://thread.gmane.org/gmane.linux.network/153338}
[Viewed June 9, 2014]"
,annotation={
        Use a pair of list_head structures to support RCU-protected
        resizable hash tables.
}
}

@mastersthesis{AbhinavDuggal2010Masters
,author="Abhinav Duggal"
,title="Stopping Data Races Using Redflag"
,school="Stony Brook University"
,year="2010"
,annotation={
        Data-race detector incorporating RCU.
        http://www.filesystems.org/docs/abhinav-thesis/abhinav_thesis.pdf
}
}

@article{JoshTriplett2010RPHash
,author="Josh Triplett and Paul E. McKenney and Jonathan Walpole"
,title="Scalable Concurrent Hash Tables via Relativistic Programming"
,journal="ACM Operating Systems Review"
,year=2010
,volume=44
,number=3
,month="July"
,annotation={
        RP fun with hash tables.
        http://portal.acm.org/citation.cfm?id=1842733.1842750
}
}

@unpublished{PaulEMcKenney2010RCUAPI
,Author="Paul E. McKenney"
,Title="The {RCU} {API}, 2010 Edition"
,month="December"
,day="8"
,year="2010"
,note="\url{http://lwn.net/Articles/418853/}"
,annotation={
        Includes updated software-engineering features.
        [Viewed December 8, 2010]
}
}

@mastersthesis{AndrejPodzimek2010masters
,author="Andrej Podzimek"
,title="Read-Copy-Update for OpenSolaris"
,school="Charles University in Prague"
,year="2010"
,note="Available:
\url{https://andrej.podzimek.org/thesis.pdf}
[Viewed January 31, 2011]"
,annotation={
        Reviews RCU implementations and creates a few for OpenSolaris.
        Drives quiescent-state detection from RCU read-side primitives,
        in a manner roughly similar to that of Jim Houston.
}
}

@unpublished{LinusTorvalds2011Linux2:6:38:rc1:NPigginVFS
,Author="Linus Torvalds"
,Title="Linux 2.6.38-rc1"
,month="January"
,year="2011"
,note="Available:
\url{https://lkml.org/lkml/2011/1/18/322}
[Viewed March 4, 2011]"
,annotation={
        "The RCU-based name lookup is at the other end of the spectrum - the
        absolute anti-gimmick. It's some seriously good stuff, and gets rid of
        the last main global lock that really tends to hurt some kernel loads.
        The dentry lock is no longer a big serializing issue. What's really
        nice about it is that it actually improves performance a lot even for
        single-threaded loads (on an SMP kernel), because it gets rid of some
        of the most expensive parts of path component lookup, which was the
        d_lock on every component lookup. So I'm seeing improvements of 30-50%
        on some seriously pathname-lookup intensive loads."
}
}

@techreport{JoshTriplett2011RPScalableCorrectOrdering
,author = {Josh Triplett and Philip W. Howard and Paul E. McKenney and Jonathan Walpole}
,title = {Scalable Correct Memory Ordering via Relativistic Programming}
,year = {2011}
,number = {11-03}
,institution = {Portland State University}
,note = {\url{http://www.cs.pdx.edu/pdfs/tr1103.pdf}}
}

@inproceedings{PhilHoward2011RCUTMRBTree
,author = {Philip W. Howard and Jonathan Walpole}
,title = {A Relativistic Enhancement to Software Transactional Memory}
,booktitle = {Proceedings of the 3rd USENIX conference on Hot topics in parallelism}
,series = {HotPar'11}
,year = {2011}
,location = {Berkeley, CA}
,pages = {1--6}
,numpages = {6}
,url = {http://www.usenix.org/event/hotpar11/tech/final_files/Howard.pdf}
,publisher = {USENIX Association}
,address = {Berkeley, CA, USA}
}

@techreport{PaulEMcKenney2011cyclicparallelRCU
,author="Paul E. McKenney and Jonathan Walpole"
,title="Efficient Support of Consistent Cyclic Search With Read-Copy Update and Parallel Updates"
,institution="US Patent and Trademark Office"
,address="Washington, DC"
,year="2011"
,number="US Patent 7,953,778"
,month="May"
,pages="34"
,annotation={
        Maintains an array of generation numbers to track in-flight
        updates and keeps an additional level of indirection to allow
        readers to confine themselves to the desired snapshot of the
        data structure.
}
}

@inproceedings{Triplett:2011:RPHash
,author = {Triplett, Josh and McKenney, Paul E. and Walpole, Jonathan}
,title = {Resizable, Scalable, Concurrent Hash Tables via Relativistic Programming}
,booktitle = {Proceedings of the 2011 USENIX Annual Technical Conference}
,month = {June}
,year = {2011}
,pages = {145--158}
,numpages = {14}
,url={http://www.usenix.org/event/atc11/tech/final_files/Triplett.pdf}
,publisher = {The USENIX Association}
,address = {Portland, OR USA}
}

@unpublished{PaulEMcKenney2011RCU3.0trainwreck
,Author="Paul E. McKenney"
,Title="3.0 and {RCU:} what went wrong"
,month="July"
,day="27"
,year="2011"
,note="\url{http://lwn.net/Articles/453002/}"
,annotation={
        Analysis of the RCU trainwreck in Linux kernel 3.0.
        [Viewed July 27, 2011]
}
}

@unpublished{NeilBrown2011MeetTheLockers
,Author="Neil Brown"
,Title="Meet the {Lockers}"
,month="August"
,day="3"
,year="2011"
,note="Available:
\url{http://lwn.net/Articles/453685/}
[Viewed September 2, 2011]"
,annotation={
        The Locker family as an analogy for locking, reference counting,
        RCU, and seqlock.
}
}

@inproceedings{Seyster:2011:RFA:2075416.2075425
,author = {Seyster, Justin and Radhakrishnan, Prabakar and Katoch, Samriti and Duggal, Abhinav and Stoller, Scott D. and Zadok, Erez}
,title = {Redflag: a framework for analysis of Kernel-level concurrency}
,booktitle = {Proceedings of the 11th international conference on Algorithms and architectures for parallel processing - Volume Part I}
,series = {ICA3PP'11}
,year = {2011}
,isbn = {978-3-642-24649-4}
,location = {Melbourne, Australia}
,pages = {66--79}
,numpages = {14}
,url = {http://dl.acm.org/citation.cfm?id=2075416.2075425}
,acmid = {2075425}
,publisher = {Springer-Verlag}
,address = {Berlin, Heidelberg}
}

@phdthesis{JoshTriplettPhD
,author="Josh Triplett"
,title="Relativistic Causal Ordering: A Memory Model for Scalable Concurrent Data Structures"
,school="Portland State University"
,year="2012"
,annotation={
        RCU-protected hash tables, barriers vs. read-side traversal order.
        .
        If the updater is making changes in the opposite direction from
        the read-side traveral order, the updater need only execute a
        memory-barrier instruction, but if in the same direction, the
        updater needs to wait for a grace period between the individual
        updates.
}
}

@article{MathieuDesnoyers2012URCU
,Author="Mathieu Desnoyers and Paul E. McKenney and Alan Stern and Michel R. Dagenais and Jonathan Walpole"
,Title="User-Level Implementations of Read-Copy Update"
,journal="IEEE Transactions on Parallel and Distributed Systems"
,volume={23}
,year="2012"
,issn="1045-9219"
,pages="375-382"
,doi="http://doi.ieeecomputersociety.org/10.1109/TPDS.2011.159"
,publisher="IEEE Computer Society"
,address="Los Alamitos, CA, USA"
,annotation={
        RCU overview, desiderata, semi-formal semantics, user-level RCU
        usage scenarios, three classes of RCU implementation, wait-free
        RCU updates, RCU grace-period batching, update overhead,
        http://www.rdrop.com/users/paulmck/RCU/urcu-main-accepted.2011.08.30a.pdf
        http://www.rdrop.com/users/paulmck/RCU/urcu-supp-accepted.2011.08.30a.pdf
        http://www.computer.org/cms/Computer.org/dl/trans/td/2012/02/extras/ttd2012020375s.pdf
}
}

@inproceedings{AustinClements2012RCULinux:mmapsem
,author = {Austin Clements and Frans Kaashoek and Nickolai Zeldovich}
,title = {Scalable Address Spaces Using {RCU} Balanced Trees}
,booktitle = {Architectural Support for Programming Languages and Operating Systems (ASPLOS 2012)}
,month = {March}
,year = {2012}
,pages = {199--210}
,numpages = {12}
,publisher = {ACM}
,address = {London, UK}
,url="http://people.csail.mit.edu/nickolai/papers/clements-bonsai.pdf"
}

@unpublished{PaulEMcKenney2012ELCbattery
,Author="Paul E. McKenney"
,Title="Making {RCU} Safe For Battery-Powered Devices"
,month="February"
,day="15"
,year="2012"
,note="Available:
\url{http://www.rdrop.com/users/paulmck/RCU/RCUdynticks.2012.02.15b.pdf}
[Viewed March 1, 2012]"
,annotation={
        RCU_FAST_NO_HZ, round 2.
}
}

@article{GuillermoVigueras2012RCUCrowd
,author = {Vigueras, Guillermo and Ordu\~{n}a, Juan M. and Lozano, Miguel}
,day = {25}
,doi = {10.1007/s11227-012-0766-x}
,issn = {0920-8542}
,journal = {The Journal of Supercomputing}
,keywords = {linux, simulation}
,month = apr
,posted-at = {2012-05-03 09:12:04}
,priority = {2}
,title = {{A Read-Copy Update based parallel server for distributed crowd simulations}}
,url = {http://dx.doi.org/10.1007/s11227-012-0766-x}
,year = {2012}
}


@unpublished{JonCorbet2012ACCESS:ONCE
,Author="Jon Corbet"
,Title="{ACCESS\_ONCE()}"
,month="August"
,day="1"
,year="2012"
,note="\url{http://lwn.net/Articles/508991/}"
,annotation={
        A couple of simple specific compiler optimizations that motivate
        ACCESS_ONCE().
}
}

@unpublished{AlexeyGotsman2012VerifyGraceExtended
,Author="Alexey Gotsman and Noam Rinetzky and Hongseok Yang"
,Title="Verifying Highly Concurrent Algorithms with Grace (extended version)"
,month="July"
,day="10"
,year="2012"
,note="\url{http://software.imdea.org/~gotsman/papers/recycling-esop13-ext.pdf}"
,annotation={
        Separation-logic formulation of RCU uses.
}
}

@unpublished{PaulMcKenney2012RCUUsage
,Author="Paul E. McKenney and Silas Boyd-Wickizer and Jonathan Walpole"
,Title="{RCU} Usage In the Linux Kernel: One Decade Later"
,month="September"
,day="17"
,year="2012"
,url=http://rdrop.com/users/paulmck/techreports/survey.2012.09.17a.pdf
,note="Technical report paulmck.2012.09.17"
,annotation={
        Overview of the first variant of no-CBs CPUs for RCU.
}
}

@unpublished{JonCorbet2012NOCB
,Author="Jon Corbet"
,Title="Relocating RCU callbacks"
,month="October"
,day="31"
,year="2012"
,note="\url{http://lwn.net/Articles/522262/}"
,annotation={
        Overview of the first variant of no-CBs CPUs for RCU.
}
}

@phdthesis{JustinSeyster2012PhD
,author="Justin Seyster"
,title="Runtime Verification of Kernel-Level Concurrency Using Compiler-Based Instrumentation"
,school="Stony Brook University"
,year="2012"
,annotation={
        Looking for data races, including those involving RCU.
        Proposal:
        http://www.fsl.cs.sunysb.edu/docs/jseyster-proposal/redflag.pdf
        Dissertation:
        http://www.fsl.cs.sunysb.edu/docs/jseyster-dissertation/redflag.pdf
}
}

@unpublished{PaulEMcKenney2013RCUUsage
,Author="Paul E. McKenney and Silas Boyd-Wickizer and Jonathan Walpole"
,Title="{RCU} Usage in the {Linux} Kernel: One Decade Later"
,month="February"
,day="24"
,year="2013"
,note="\url{http://rdrop.com/users/paulmck/techreports/RCUUsage.2013.02.24a.pdf}"
,annotation={
        Usage of RCU within the Linux kernel.
}
}

@inproceedings{AlexeyGotsman2013ESOPRCU
,author = {Alexey Gotsman and Noam Rinetzky and Hongseok Yang}
,title = {Verifying concurrent memory reclamation algorithms with grace}
,booktitle = {ESOP'13: European Symposium on Programming}
,year = {2013}
,pages = {249--269}
,publisher = {Springer}
,address = {Rome, Italy}
,annotation={
        http://software.imdea.org/~gotsman/papers/recycling-esop13.pdf
}
}

@unpublished{PaulEMcKenney2013NoTinyPreempt
,Author="Paul E. McKenney"
,Title="Simplifying RCU"
,month="March"
,day="6"
,year="2013"
,note="\url{http://lwn.net/Articles/541037/}"
,annotation={
        Getting rid of TINY_PREEMPT_RCU.
}
}