2017-10-04 16:33:43 +00:00
|
|
|
/*
|
2010-05-17 22:18:00 +00:00
|
|
|
* 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/>.
|
2017-10-04 16:33:43 +00:00
|
|
|
*/
|
2010-05-17 22:18:00 +00:00
|
|
|
|
2018-02-15 01:01:15 +00:00
|
|
|
#ifndef _SPL_SHRINKER_H
|
|
|
|
|
#define _SPL_SHRINKER_H
|
2009-11-10 22:06:57 +00:00
|
|
|
|
|
|
|
|
#include <linux/mm.h>
|
2011-02-23 20:25:45 +00:00
|
|
|
#include <linux/fs.h>
|
2009-11-10 22:06:57 +00:00
|
|
|
|
2011-06-16 22:39:08 +00:00
|
|
|
/*
|
2013-11-05 16:35:54 +00:00
|
|
|
* Due to frequent changes in the shrinker API the following
|
2023-12-16 13:36:21 +00:00
|
|
|
* compatibility wrapper should be used.
|
2013-11-05 16:35:54 +00:00
|
|
|
*
|
2023-12-16 13:36:21 +00:00
|
|
|
* shrinker = spl_register_shrinker(name, countfunc, scanfunc, seek_cost);
|
|
|
|
|
* spl_unregister_shrinker(shrinker);
|
2013-11-05 16:35:54 +00:00
|
|
|
*
|
2023-12-16 13:36:21 +00:00
|
|
|
* spl_register_shrinker is used to create and register a shrinker with the
|
|
|
|
|
* given name.
|
Revise SPL wrapper for shrinker callbacks
The SPL provides a wrapper for the kernel's shrinker callbacks, which
enables the ZFS code to interface with multiple versions of the shrinker
API's from different kernel versions. Specifically, Linux kernels 3.0 -
3.11 has a single "combined" callback, and Linux kernels 3.12 and later
have two "split" callbacks. The SPL provides a wrapper function so that
the ZFS code only needs to implement one version of the callbacks.
Currently the SPL's wrappers are designed such that the ZFS code
implements the older, "combined" callback. There are a few downsides to
this approach:
* The general design within ZFS is for the latest Linux kernel to be
considered the "first class" API.
* The newer, "split" callback API is easier to understand, because each
callback has one purpose.
* The current wrappers do not completely abstract out the differing
API's, so ZFS code needs `#ifdef` code to handle the differing return
values required for different kernel versions.
This commit addresses these drawbacks by having the ZFS code provide the
latest, "split" callbacks, and the SPL provides a wrapping function for
the older, "combined" API.
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10502
2020-06-27 17:27:02 +00:00
|
|
|
* The countfunc returns the number of free-able objects.
|
|
|
|
|
* The scanfunc returns the number of objects that were freed.
|
|
|
|
|
* The callbacks can return SHRINK_STOP if further calls can't make any more
|
|
|
|
|
* progress. Note that a return value of SHRINK_EMPTY is currently not
|
|
|
|
|
* supported.
|
2013-11-05 16:35:54 +00:00
|
|
|
*
|
|
|
|
|
* Example:
|
|
|
|
|
*
|
Revise SPL wrapper for shrinker callbacks
The SPL provides a wrapper for the kernel's shrinker callbacks, which
enables the ZFS code to interface with multiple versions of the shrinker
API's from different kernel versions. Specifically, Linux kernels 3.0 -
3.11 has a single "combined" callback, and Linux kernels 3.12 and later
have two "split" callbacks. The SPL provides a wrapper function so that
the ZFS code only needs to implement one version of the callbacks.
Currently the SPL's wrappers are designed such that the ZFS code
implements the older, "combined" callback. There are a few downsides to
this approach:
* The general design within ZFS is for the latest Linux kernel to be
considered the "first class" API.
* The newer, "split" callback API is easier to understand, because each
callback has one purpose.
* The current wrappers do not completely abstract out the differing
API's, so ZFS code needs `#ifdef` code to handle the differing return
values required for different kernel versions.
This commit addresses these drawbacks by having the ZFS code provide the
latest, "split" callbacks, and the SPL provides a wrapping function for
the older, "combined" API.
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10502
2020-06-27 17:27:02 +00:00
|
|
|
* static unsigned long
|
|
|
|
|
* my_count(struct shrinker *shrink, struct shrink_control *sc)
|
2013-11-05 16:35:54 +00:00
|
|
|
* {
|
|
|
|
|
* ...calculate number of objects in the cache...
|
|
|
|
|
*
|
|
|
|
|
* return (number of objects in the cache);
|
|
|
|
|
* }
|
Revise SPL wrapper for shrinker callbacks
The SPL provides a wrapper for the kernel's shrinker callbacks, which
enables the ZFS code to interface with multiple versions of the shrinker
API's from different kernel versions. Specifically, Linux kernels 3.0 -
3.11 has a single "combined" callback, and Linux kernels 3.12 and later
have two "split" callbacks. The SPL provides a wrapper function so that
the ZFS code only needs to implement one version of the callbacks.
Currently the SPL's wrappers are designed such that the ZFS code
implements the older, "combined" callback. There are a few downsides to
this approach:
* The general design within ZFS is for the latest Linux kernel to be
considered the "first class" API.
* The newer, "split" callback API is easier to understand, because each
callback has one purpose.
* The current wrappers do not completely abstract out the differing
API's, so ZFS code needs `#ifdef` code to handle the differing return
values required for different kernel versions.
This commit addresses these drawbacks by having the ZFS code provide the
latest, "split" callbacks, and the SPL provides a wrapping function for
the older, "combined" API.
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10502
2020-06-27 17:27:02 +00:00
|
|
|
*
|
|
|
|
|
* static unsigned long
|
|
|
|
|
* my_scan(struct shrinker *shrink, struct shrink_control *sc)
|
|
|
|
|
* {
|
|
|
|
|
* ...scan objects in the cache and reclaim them...
|
|
|
|
|
* }
|
|
|
|
|
*
|
2023-12-16 13:36:21 +00:00
|
|
|
* static struct shrinker *my_shrinker;
|
Revise SPL wrapper for shrinker callbacks
The SPL provides a wrapper for the kernel's shrinker callbacks, which
enables the ZFS code to interface with multiple versions of the shrinker
API's from different kernel versions. Specifically, Linux kernels 3.0 -
3.11 has a single "combined" callback, and Linux kernels 3.12 and later
have two "split" callbacks. The SPL provides a wrapper function so that
the ZFS code only needs to implement one version of the callbacks.
Currently the SPL's wrappers are designed such that the ZFS code
implements the older, "combined" callback. There are a few downsides to
this approach:
* The general design within ZFS is for the latest Linux kernel to be
considered the "first class" API.
* The newer, "split" callback API is easier to understand, because each
callback has one purpose.
* The current wrappers do not completely abstract out the differing
API's, so ZFS code needs `#ifdef` code to handle the differing return
values required for different kernel versions.
This commit addresses these drawbacks by having the ZFS code provide the
latest, "split" callbacks, and the SPL provides a wrapping function for
the older, "combined" API.
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10502
2020-06-27 17:27:02 +00:00
|
|
|
*
|
|
|
|
|
* void my_init_func(void) {
|
2023-12-16 13:36:21 +00:00
|
|
|
* my_shrinker = spl_register_shrinker("my-shrinker",
|
|
|
|
|
* my_count, my_scan, DEFAULT_SEEKS);
|
|
|
|
|
* }
|
|
|
|
|
*
|
|
|
|
|
* void my_fini_func(void) {
|
|
|
|
|
* spl_unregister_shrinker(my_shrinker);
|
Revise SPL wrapper for shrinker callbacks
The SPL provides a wrapper for the kernel's shrinker callbacks, which
enables the ZFS code to interface with multiple versions of the shrinker
API's from different kernel versions. Specifically, Linux kernels 3.0 -
3.11 has a single "combined" callback, and Linux kernels 3.12 and later
have two "split" callbacks. The SPL provides a wrapper function so that
the ZFS code only needs to implement one version of the callbacks.
Currently the SPL's wrappers are designed such that the ZFS code
implements the older, "combined" callback. There are a few downsides to
this approach:
* The general design within ZFS is for the latest Linux kernel to be
considered the "first class" API.
* The newer, "split" callback API is easier to understand, because each
callback has one purpose.
* The current wrappers do not completely abstract out the differing
API's, so ZFS code needs `#ifdef` code to handle the differing return
values required for different kernel versions.
This commit addresses these drawbacks by having the ZFS code provide the
latest, "split" callbacks, and the SPL provides a wrapping function for
the older, "combined" API.
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10502
2020-06-27 17:27:02 +00:00
|
|
|
* }
|
2011-06-16 22:39:08 +00:00
|
|
|
*/
|
2011-03-23 22:45:55 +00:00
|
|
|
|
2023-12-16 13:36:21 +00:00
|
|
|
typedef unsigned long (*spl_shrinker_cb)
|
|
|
|
|
(struct shrinker *, struct shrink_control *);
|
2011-03-23 22:45:55 +00:00
|
|
|
|
2023-12-16 13:36:21 +00:00
|
|
|
struct shrinker *spl_register_shrinker(const char *name,
|
|
|
|
|
spl_shrinker_cb countfunc, spl_shrinker_cb scanfunc, int seek_cost);
|
|
|
|
|
void spl_unregister_shrinker(struct shrinker *);
|
2011-06-16 22:39:08 +00:00
|
|
|
|
2023-12-16 13:36:21 +00:00
|
|
|
#ifndef SHRINK_STOP
|
|
|
|
|
/* 3.0-3.11 compatibility */
|
Revise SPL wrapper for shrinker callbacks
The SPL provides a wrapper for the kernel's shrinker callbacks, which
enables the ZFS code to interface with multiple versions of the shrinker
API's from different kernel versions. Specifically, Linux kernels 3.0 -
3.11 has a single "combined" callback, and Linux kernels 3.12 and later
have two "split" callbacks. The SPL provides a wrapper function so that
the ZFS code only needs to implement one version of the callbacks.
Currently the SPL's wrappers are designed such that the ZFS code
implements the older, "combined" callback. There are a few downsides to
this approach:
* The general design within ZFS is for the latest Linux kernel to be
considered the "first class" API.
* The newer, "split" callback API is easier to understand, because each
callback has one purpose.
* The current wrappers do not completely abstract out the differing
API's, so ZFS code needs `#ifdef` code to handle the differing return
values required for different kernel versions.
This commit addresses these drawbacks by having the ZFS code provide the
latest, "split" callbacks, and the SPL provides a wrapping function for
the older, "combined" API.
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10502
2020-06-27 17:27:02 +00:00
|
|
|
#define SHRINK_STOP (-1)
|
2013-11-05 16:35:54 +00:00
|
|
|
#endif
|
2011-03-23 22:45:55 +00:00
|
|
|
|
2018-02-15 01:01:15 +00:00
|
|
|
#endif /* SPL_SHRINKER_H */
|
