module/os/linux/spl/spl-shrinker.c

   1 /*
   2  *  Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
   3  *  Copyright (C) 2007 The Regents of the University of California.
   4  *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
   5  *  Written by Brian Behlendorf <behlendorf1@llnl.gov>.
   6  *  UCRL-CODE-235197
   7  *
   8  *  This file is part of the SPL, Solaris Porting Layer.
   9  *
  10  *  The SPL is free software; you can redistribute it and/or modify it
  11  *  under the terms of the GNU General Public License as published by the
  12  *  Free Software Foundation; either version 2 of the License, or (at your
  13  *  option) any later version.
  14  *
  15  *  The SPL is distributed in the hope that it will be useful, but WITHOUT
  16  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  17  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  18  *  for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License along
  21  *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
  22  *
  23  *  Solaris Porting Layer (SPL) Shrinker Implementation.
  24  */
  25
  26 #include <sys/kmem.h>
  27 #include <sys/shrinker.h>
  28
  29 struct shrinker *
  30 spl_register_shrinker(const char *name, spl_shrinker_cb countfunc,
  31     spl_shrinker_cb scanfunc, int seek_cost)
  32 {
  33         struct shrinker *shrinker;
  34
  35         /* allocate shrinker */
  36 #ifdef HAVE_SHRINKER_REGISTER
  37         /* 6.7: kernel will allocate the shrinker for us */
  38         shrinker = shrinker_alloc(0, name);
  39 #else
  40         /* 4.4-6.6: we allocate the shrinker  */
  41         shrinker = kmem_zalloc(sizeof (struct shrinker), KM_SLEEP);
  42 #endif
  43
  44         if (shrinker == NULL)
  45                 return (NULL);
  46
  47         /* set callbacks */
  48         shrinker->count_objects = countfunc;
  49         shrinker->scan_objects = scanfunc;
  50
  51         /* set params */
  52         shrinker->seeks = seek_cost;
  53
  54         /* register with kernel */
  55 #if defined(HAVE_SHRINKER_REGISTER)
  56         shrinker_register(shrinker);
  57 #elif defined(HAVE_REGISTER_SHRINKER_VARARG)
  58         register_shrinker(shrinker, name);
  59 #else
  60         register_shrinker(shrinker);
  61 #endif
  62
  63         return (shrinker);
  64 }
  65 EXPORT_SYMBOL(spl_register_shrinker);
  66
  67 void
  68 spl_unregister_shrinker(struct shrinker *shrinker)
  69 {
  70 #if defined(HAVE_SHRINKER_REGISTER)
  71         shrinker_free(shrinker);
  72 #else
  73         unregister_shrinker(shrinker);
  74         kmem_free(shrinker, sizeof (struct shrinker));
  75 #endif
  76 }
  77 EXPORT_SYMBOL(spl_unregister_shrinker);