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/*
* Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
* Copyright (C) 2007 The Regents of the University of California.
* Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
* Written by Brian Behlendorf <behlendorf1@llnl.gov>.
* UCRL-CODE-235197
*
* This file is part of the SPL, Solaris Porting Layer.
*
* The SPL is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* The SPL is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with the SPL. If not, see <http://www.gnu.org/licenses/>.
*
* Solaris Porting Layer (SPL) Shrinker Implementation.
*/
#include <sys/kmem.h>
#include <sys/shrinker.h>
#ifdef HAVE_SINGLE_SHRINKER_CALLBACK
/* 3.0-3.11: single shrink() callback, which we wrap to carry both functions */
struct spl_shrinker_wrap {
struct shrinker shrinker;
spl_shrinker_cb countfunc;
spl_shrinker_cb scanfunc;
};
static int
spl_shrinker_single_cb(struct shrinker *shrinker, struct shrink_control *sc)
{
struct spl_shrinker_wrap *sw = (struct spl_shrinker_wrap *)shrinker;
if (sc->nr_to_scan != 0)
(void) sw->scanfunc(&sw->shrinker, sc);
return (sw->countfunc(&sw->shrinker, sc));
}
#endif
struct shrinker *
spl_register_shrinker(const char *name, spl_shrinker_cb countfunc,
spl_shrinker_cb scanfunc, int seek_cost)
{
struct shrinker *shrinker;
/* allocate shrinker */
#if defined(HAVE_SHRINKER_REGISTER)
/* 6.7: kernel will allocate the shrinker for us */
shrinker = shrinker_alloc(0, name);
#elif defined(HAVE_SPLIT_SHRINKER_CALLBACK)
/* 3.12-6.6: we allocate the shrinker */
shrinker = kmem_zalloc(sizeof (struct shrinker), KM_SLEEP);
#elif defined(HAVE_SINGLE_SHRINKER_CALLBACK)
/* 3.0-3.11: allocate a wrapper */
struct spl_shrinker_wrap *sw =
kmem_zalloc(sizeof (struct spl_shrinker_wrap), KM_SLEEP);
shrinker = &sw->shrinker;
#else
/* 2.x-2.6.22, or a newer shrinker API has been introduced. */
#error "Unknown shrinker API"
#endif
if (shrinker == NULL)
return (NULL);
/* set callbacks */
#ifdef HAVE_SINGLE_SHRINKER_CALLBACK
sw->countfunc = countfunc;
sw->scanfunc = scanfunc;
shrinker->shrink = spl_shrinker_single_cb;
#else
shrinker->count_objects = countfunc;
shrinker->scan_objects = scanfunc;
#endif
/* set params */
shrinker->seeks = seek_cost;
/* register with kernel */
#if defined(HAVE_SHRINKER_REGISTER)
shrinker_register(shrinker);
#elif defined(HAVE_REGISTER_SHRINKER_VARARG)
register_shrinker(shrinker, name);
#else
register_shrinker(shrinker);
#endif
return (shrinker);
}
EXPORT_SYMBOL(spl_register_shrinker);
void
spl_unregister_shrinker(struct shrinker *shrinker)
{
#if defined(HAVE_SHRINKER_REGISTER)
shrinker_free(shrinker);
#elif defined(HAVE_SPLIT_SHRINKER_CALLBACK)
unregister_shrinker(shrinker);
kmem_free(shrinker, sizeof (struct shrinker));
#elif defined(HAVE_SINGLE_SHRINKER_CALLBACK)
unregister_shrinker(shrinker);
kmem_free(shrinker, sizeof (struct spl_shrinker_wrap));
#else
#error "Unknown shrinker API"
#endif
}
EXPORT_SYMBOL(spl_unregister_shrinker);
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