include/sys/dmu_zfetch.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or https://opensource.org/licenses/CDDL-1.0.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 /*
  27  * Copyright (c) 2014, 2017 by Delphix. All rights reserved.
  28  */
  29
  30 #ifndef _DMU_ZFETCH_H
  31 #define _DMU_ZFETCH_H
  32
  33 #include <sys/zfs_context.h>
  34
  35 #ifdef  __cplusplus
  36 extern "C" {
  37 #endif
  38
  39 struct dnode;                           /* so we can reference dnode */
  40
  41 typedef struct zfetch {
  42         kmutex_t        zf_lock;        /* protects zfetch structure */
  43         list_t          zf_stream;      /* list of zstream_t's */
  44         struct dnode    *zf_dnode;      /* dnode that owns this zfetch */
  45         int             zf_numstreams;  /* number of zstream_t's */
  46 } zfetch_t;
  47
  48 typedef struct zsrange {
  49         uint16_t        start;
  50         uint16_t        end;
  51 } zsrange_t;
  52
  53 #define ZFETCH_RANGES   9               /* Fits zstream_t into 128 bytes */
  54
  55 typedef struct zstream {
  56         list_node_t     zs_node;        /* link for zf_stream */
  57         uint64_t        zs_blkid;       /* expect next access at this blkid */
  58         uint_t          zs_atime;       /* time last prefetch issued */
  59         zsrange_t       zs_ranges[ZFETCH_RANGES]; /* ranges from future */
  60         unsigned int    zs_pf_dist;     /* data prefetch distance in bytes */
  61         unsigned int    zs_ipf_dist;    /* L1 prefetch distance in bytes */
  62         uint64_t        zs_pf_start;    /* first data block to prefetch */
  63         uint64_t        zs_pf_end;      /* data block to prefetch up to */
  64         uint64_t        zs_ipf_start;   /* first data block to prefetch L1 */
  65         uint64_t        zs_ipf_end;     /* data block to prefetch L1 up to */
  66         boolean_t       zs_missed;      /* stream saw cache misses */
  67         boolean_t       zs_more;        /* need more distant prefetch */
  68         zfs_refcount_t  zs_callers;     /* number of pending callers */
  69         /*
  70          * Number of stream references: dnode, callers and pending blocks.
  71          * The stream memory is freed when the number returns to zero.
  72          */
  73         zfs_refcount_t  zs_refs;
  74 } zstream_t;
  75
  76 void            zfetch_init(void);
  77 void            zfetch_fini(void);
  78
  79 void            dmu_zfetch_init(zfetch_t *, struct dnode *);
  80 void            dmu_zfetch_fini(zfetch_t *);
  81 zstream_t       *dmu_zfetch_prepare(zfetch_t *, uint64_t, uint64_t, boolean_t,
  82     boolean_t);
  83 void            dmu_zfetch_run(zfetch_t *, zstream_t *, boolean_t, boolean_t);
  84 void            dmu_zfetch(zfetch_t *, uint64_t, uint64_t, boolean_t, boolean_t,
  85     boolean_t);
  86
  87
  88 #ifdef  __cplusplus
  89 }
  90 #endif
  91
  92 #endif  /* _DMU_ZFETCH_H */