mirror_zfs/include/linux/mm_compat.h
Brian Behlendorf fe71c0e567 Linux 3.1 compat, shrink_*cache_memory
As of Linux 3.1 the shrink_dcache_memory and shrink_icache_memory
functions have been removed.  This same task is now accomplished
more cleanly with per super block shrinkers.  This unfortunately
leaves us no easy way to support the dnlc_reduce_cache() function.

This support has always been entirely optional.  So when no
reasonable interface is available allow the dnlc_reduce_cache()
function to effectively become a no-op.

The downside of this change is that it will prevent the zfs arc
meta data limts from being enforced.  However, the current zfs
implementation in this regard is already flawed and needs to
be reworked.  If the arc needs to enfore a meta data limit it
will need to be extended to coordinate directly with the zpl.
This will allow us to drop all this compatibility code and get
more fine grained control over the cache management.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #52
2011-11-09 19:36:30 -08:00

283 lines
12 KiB
C

/*****************************************************************************\
* 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.
* For details, see <http://github.com/behlendorf/spl/>.
*
* 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/>.
\*****************************************************************************/
#ifndef _SPL_MM_COMPAT_H
#define _SPL_MM_COMPAT_H
#include <linux/mm.h>
#include <linux/fs.h>
/*
* Linux 2.6.31 API Change.
* Individual pages_{min,low,high} moved in to watermark array.
*/
#ifndef min_wmark_pages
#define min_wmark_pages(z) (z->pages_min)
#endif
#ifndef low_wmark_pages
#define low_wmark_pages(z) (z->pages_low)
#endif
#ifndef high_wmark_pages
#define high_wmark_pages(z) (z->pages_high)
#endif
/*
* 2.6.37 API compat,
* The function invalidate_inodes() is no longer exported by the kernel.
* The prototype however is still available which means it is safe
* to acquire the symbol's address using spl_kallsyms_lookup_name().
*
* 2.6.39 API compat,
* As for 2.6.39 invalidate_inodes() was updated to take a second
* argument which controls how dirty inodes should be handled.
*/
#ifdef HAVE_INVALIDATE_INODES
# ifdef HAVE_2ARGS_INVALIDATE_INODES
# define spl_invalidate_inodes(sb, kd) invalidate_inodes(sb, kd)
# else
# define spl_invalidate_inodes(sb, kd) invalidate_inodes(sb)
# endif /* HAVE_2ARGS_INVALIDATE_INODES */
#else
# ifdef HAVE_2ARGS_INVALIDATE_INODES
typedef int (*invalidate_inodes_t)(struct super_block *sb, bool kd);
extern invalidate_inodes_t invalidate_inodes_fn;
# define spl_invalidate_inodes(sb, kd) invalidate_inodes_fn(sb, kd)
# else
typedef int (*invalidate_inodes_t)(struct super_block *sb);
extern invalidate_inodes_t invalidate_inodes_fn;
# define spl_invalidate_inodes(sb, kd) invalidate_inodes_fn(sb)
# endif /* HAVE_2ARGS_INVALIDATE_INODES */
#endif /* HAVE_INVALIDATE_INODES */
#if !defined(HAVE_SHRINK_CONTROL_STRUCT)
struct shrink_control {
gfp_t gfp_mask;
unsigned long nr_to_scan;
};
#endif /* HAVE_SHRINK_CONTROL_STRUCT */
/*
* 2.6.xx API compat,
* There currently exists no exposed API to partially shrink the dcache.
* The expected mechanism to shrink the cache is a registered shrinker
* which is called during memory pressure.
*/
#ifndef HAVE_SHRINK_DCACHE_MEMORY
# if defined(HAVE_SHRINK_CONTROL_STRUCT)
typedef int (*shrink_dcache_memory_t)(struct shrinker *,
struct shrink_control *);
extern shrink_dcache_memory_t shrink_dcache_memory_fn;
# define shrink_dcache_memory(nr, gfp) \
({ \
struct shrink_control sc = { .nr_to_scan = nr, .gfp_mask = gfp }; \
int __ret__ = 0; \
\
if (shrink_dcache_memory_fn) \
__ret__ = shrink_dcache_memory_fn(NULL, &sc); \
\
__ret__; \
})
# elif defined(HAVE_3ARGS_SHRINKER_CALLBACK)
typedef int (*shrink_dcache_memory_t)(struct shrinker *, int, gfp_t);
extern shrink_dcache_memory_t shrink_dcache_memory_fn;
# define shrink_dcache_memory(nr, gfp) \
({ \
int __ret__ = 0; \
\
if (shrink_dcache_memory_fn) \
__ret__ = shrink_dcache_memory_fn(NULL, nr, gfp); \
\
__ret__; \
})
# else
typedef int (*shrink_dcache_memory_t)(int, gfp_t);
extern shrink_dcache_memory_t shrink_dcache_memory_fn;
# define shrink_dcache_memory(nr, gfp) \
({ \
int __ret__ = 0; \
\
if (shrink_dcache_memory_fn) \
__ret__ = shrink_dcache_memory_fn(nr, gfp); \
\
__ret__; \
})
# endif /* HAVE_3ARGS_SHRINKER_CALLBACK */
#endif /* HAVE_SHRINK_DCACHE_MEMORY */
/*
* 2.6.xx API compat,
* There currently exists no exposed API to partially shrink the icache.
* The expected mechanism to shrink the cache is a registered shrinker
* which is called during memory pressure.
*/
#ifndef HAVE_SHRINK_ICACHE_MEMORY
# if defined(HAVE_SHRINK_CONTROL_STRUCT)
typedef int (*shrink_icache_memory_t)(struct shrinker *,
struct shrink_control *);
extern shrink_icache_memory_t shrink_icache_memory_fn;
# define shrink_icache_memory(nr, gfp) \
({ \
struct shrink_control sc = { .nr_to_scan = nr, .gfp_mask = gfp }; \
int __ret__ = 0; \
\
if (shrink_icache_memory_fn) \
__ret__ = shrink_icache_memory_fn(NULL, &sc); \
\
__ret__; \
})
# elif defined(HAVE_3ARGS_SHRINKER_CALLBACK)
typedef int (*shrink_icache_memory_t)(struct shrinker *, int, gfp_t);
extern shrink_icache_memory_t shrink_icache_memory_fn;
# define shrink_icache_memory(nr, gfp) \
({ \
int __ret__ = 0; \
\
if (shrink_icache_memory_fn) \
__ret__ = shrink_icache_memory_fn(NULL, nr, gfp); \
\
__ret__; \
})
# else
typedef int (*shrink_icache_memory_t)(int, gfp_t);
extern shrink_icache_memory_t shrink_icache_memory_fn;
# define shrink_icache_memory(nr, gfp) \
({ \
int __ret__ = 0; \
\
if (shrink_icache_memory_fn) \
__ret__ = shrink_icache_memory_fn(nr, gfp); \
\
__ret__; \
})
# endif /* HAVE_3ARGS_SHRINKER_CALLBACK */
#endif /* HAVE_SHRINK_ICACHE_MEMORY */
/*
* Linux 2.6. - 2.6. Shrinker API Compatibility.
*/
#ifdef HAVE_SET_SHRINKER
typedef struct spl_shrinker {
struct shrinker *shrinker;
shrinker_t fn;
int seeks;
} spl_shrinker_t;
static inline void
spl_register_shrinker(spl_shrinker_t *ss)
{
ss->shrinker = set_shrinker(ss->seeks, ss->fn);
}
static inline void
spl_unregister_shrinker(spl_shrinker_t *ss)
{
remove_shrinker(ss->shrinker);
}
# define SPL_SHRINKER_DECLARE(s, x, y) \
static spl_shrinker_t s = { \
.shrinker = NULL, \
.fn = x, \
.seeks = y \
}
# define SPL_SHRINKER_CALLBACK_FWD_DECLARE(fn) \
static int fn(int, unsigned int)
# define SPL_SHRINKER_CALLBACK_WRAPPER(fn) \
static int \
fn(int nr_to_scan, unsigned int gfp_mask) \
{ \
struct shrink_control sc; \
\
sc.nr_to_scan = nr_to_scan; \
sc.gfp_mask = gfp_mask; \
\
return __ ## fn(NULL, &sc); \
}
#else
# define spl_register_shrinker(x) register_shrinker(x)
# define spl_unregister_shrinker(x) unregister_shrinker(x)
# define SPL_SHRINKER_DECLARE(s, x, y) \
static struct shrinker s = { \
.shrink = x, \
.seeks = y \
}
/*
* Linux 2.6. - 2.6. Shrinker API Compatibility.
*/
# if defined(HAVE_SHRINK_CONTROL_STRUCT)
# define SPL_SHRINKER_CALLBACK_FWD_DECLARE(fn) \
static int fn(struct shrinker *, struct shrink_control *)
# define SPL_SHRINKER_CALLBACK_WRAPPER(fn) \
static int \
fn(struct shrinker *shrink, struct shrink_control *sc) { \
return __ ## fn(shrink, sc); \
}
/*
* Linux 2.6. - 2.6. Shrinker API Compatibility.
*/
# elif defined(HAVE_3ARGS_SHRINKER_CALLBACK)
# define SPL_SHRINKER_CALLBACK_FWD_DECLARE(fn) \
static int fn(struct shrinker *, int, unsigned int)
# define SPL_SHRINKER_CALLBACK_WRAPPER(fn) \
static int \
fn(struct shrinker *shrink, int nr_to_scan, unsigned int gfp_mask) \
{ \
struct shrink_control sc; \
\
sc.nr_to_scan = nr_to_scan; \
sc.gfp_mask = gfp_mask; \
\
return __ ## fn(shrink, &sc); \
}
/*
* Linux 2.6. - 2.6. Shrinker API Compatibility.
*/
# else
# define SPL_SHRINKER_CALLBACK_FWD_DECLARE(fn) \
static int fn(int, unsigned int)
# define SPL_SHRINKER_CALLBACK_WRAPPER(fn) \
static int \
fn(int nr_to_scan, unsigned int gfp_mask) \
{ \
struct shrink_control sc; \
\
sc.nr_to_scan = nr_to_scan; \
sc.gfp_mask = gfp_mask; \
\
return __ ## fn(NULL, &sc); \
}
# endif
#endif /* HAVE_SET_SHRINKER */
#endif /* SPL_MM_COMPAT_H */