The patch titled
mm: clean up and kernelify shrinker registration
has been added to the -mm tree. Its filename is
mm-clean-up-and-kernelify-shrinker-registration.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: mm: clean up and kernelify shrinker registration
From: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
I can never remember what the function to register to receive VM pressure
is called. I have to trace down from __alloc_pages() to find it.
It's called "set_shrinker()", and it needs Your Help.
1) Don't hide struct shrinker. It contains no magic.
2) Don't allocate "struct shrinker". It's not helpful.
3) Call them "register_shrinker" and "unregister_shrinker".
4) Call the function "shrink" not "shrinker".
5) Reduce the 17 lines of waffly comments to 13, but document it properly.
Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Cc: David Chinner <dgc@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86_64/kernel/functionlist | 1
fs/dcache.c | 9 +++++-
fs/dquot.c | 7 ++++-
fs/inode.c | 7 ++++-
fs/mbcache.c | 9 ++++--
fs/nfs/super.c | 10 ++++---
fs/xfs/linux-2.6/xfs_buf.c | 14 ++++------
fs/xfs/quota/xfs_qm.c | 10 +++++--
include/linux/mm.h | 40 +++++++++++++++-------------
mm/vmscan.c | 42 +++++++-----------------------
10 files changed, 77 insertions(+), 72 deletions(-)
diff -puN arch/x86_64/kernel/functionlist~mm-clean-up-and-kernelify-shrinker-registration arch/x86_64/kernel/functionlist
--- a/arch/x86_64/kernel/functionlist~mm-clean-up-and-kernelify-shrinker-registration
+++ a/arch/x86_64/kernel/functionlist
@@ -1118,7 +1118,6 @@
*(.text.simple_strtoll)
*(.text.set_termios)
*(.text.set_task_comm)
-*(.text.set_shrinker)
*(.text.set_normalized_timespec)
*(.text.set_brk)
*(.text.serial_in)
diff -puN fs/dcache.c~mm-clean-up-and-kernelify-shrinker-registration fs/dcache.c
--- a/fs/dcache.c~mm-clean-up-and-kernelify-shrinker-registration
+++ a/fs/dcache.c
@@ -854,6 +854,11 @@ static int shrink_dcache_memory(int nr,
return (dentry_stat.nr_unused / 100) * sysctl_vfs_cache_pressure;
}
+static struct shrinker dcache_shrinker = {
+ .shrink = shrink_dcache_memory,
+ .seeks = DEFAULT_SEEKS,
+};
+
/**
* d_alloc - allocate a dcache entry
* @parent: parent of entry to allocate
@@ -2058,8 +2063,8 @@ static void __init dcache_init(unsigned
(SLAB_RECLAIM_ACCOUNT|SLAB_PANIC|
SLAB_MEM_SPREAD),
NULL, NULL);
-
- set_shrinker(DEFAULT_SEEKS, shrink_dcache_memory);
+
+ register_shrinker(&dcache_shrinker);
/* Hash may have been set up in dcache_init_early */
if (!hashdist)
diff -puN fs/dquot.c~mm-clean-up-and-kernelify-shrinker-registration fs/dquot.c
--- a/fs/dquot.c~mm-clean-up-and-kernelify-shrinker-registration
+++ a/fs/dquot.c
@@ -539,6 +539,11 @@ static int shrink_dqcache_memory(int nr,
return (dqstats.free_dquots / 100) * sysctl_vfs_cache_pressure;
}
+static struct shrinker dqcache_shrinker = {
+ .shrink = shrink_dqcache_memory,
+ .seeks = DEFAULT_SEEKS,
+};
+
/*
* Put reference to dquot
* NOTE: If you change this function please check whether dqput_blocks() works right...
@@ -1870,7 +1875,7 @@ static int __init dquot_init(void)
printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n",
nr_hash, order, (PAGE_SIZE << order));
- set_shrinker(DEFAULT_SEEKS, shrink_dqcache_memory);
+ register_shrinker(&dqcache_shrinker);
return 0;
}
diff -puN fs/inode.c~mm-clean-up-and-kernelify-shrinker-registration fs/inode.c
--- a/fs/inode.c~mm-clean-up-and-kernelify-shrinker-registration
+++ a/fs/inode.c
@@ -464,6 +464,11 @@ static int shrink_icache_memory(int nr,
return (inodes_stat.nr_unused / 100) * sysctl_vfs_cache_pressure;
}
+static struct shrinker icache_shrinker = {
+ .shrink = shrink_icache_memory,
+ .seeks = DEFAULT_SEEKS,
+};
+
static void __wait_on_freeing_inode(struct inode *inode);
/*
* Called with the inode lock held.
@@ -1381,7 +1386,7 @@ void __init inode_init(unsigned long mem
SLAB_MEM_SPREAD),
init_once,
NULL);
- set_shrinker(DEFAULT_SEEKS, shrink_icache_memory);
+ register_shrinker(&icache_shrinker);
/* Hash may have been set up in inode_init_early */
if (!hashdist)
diff -puN fs/mbcache.c~mm-clean-up-and-kernelify-shrinker-registration fs/mbcache.c
--- a/fs/mbcache.c~mm-clean-up-and-kernelify-shrinker-registration
+++ a/fs/mbcache.c
@@ -100,7 +100,6 @@ struct mb_cache {
static LIST_HEAD(mb_cache_list);
static LIST_HEAD(mb_cache_lru_list);
static DEFINE_SPINLOCK(mb_cache_spinlock);
-static struct shrinker *mb_shrinker;
static inline int
mb_cache_indexes(struct mb_cache *cache)
@@ -118,6 +117,10 @@ mb_cache_indexes(struct mb_cache *cache)
static int mb_cache_shrink_fn(int nr_to_scan, gfp_t gfp_mask);
+static struct shrinker mb_cache_shrinker = {
+ .shrink = mb_cache_shrink_fn,
+ .seeks = DEFAULT_SEEKS,
+};
static inline int
__mb_cache_entry_is_hashed(struct mb_cache_entry *ce)
@@ -662,13 +665,13 @@ mb_cache_entry_find_next(struct mb_cache
static int __init init_mbcache(void)
{
- mb_shrinker = set_shrinker(DEFAULT_SEEKS, mb_cache_shrink_fn);
+ register_shrinker(&mb_cache_shrinker);
return 0;
}
static void __exit exit_mbcache(void)
{
- remove_shrinker(mb_shrinker);
+ unregister_shrinker(&mb_cache_shrinker);
}
module_init(init_mbcache)
diff -puN fs/nfs/super.c~mm-clean-up-and-kernelify-shrinker-registration fs/nfs/super.c
--- a/fs/nfs/super.c~mm-clean-up-and-kernelify-shrinker-registration
+++ a/fs/nfs/super.c
@@ -138,7 +138,10 @@ static const struct super_operations nfs
};
#endif
-static struct shrinker *acl_shrinker;
+static struct shrinker acl_shrinker = {
+ .shrink = nfs_access_cache_shrinker,
+ .seeks = DEFAULT_SEEKS,
+};
/*
* Register the NFS filesystems
@@ -159,7 +162,7 @@ int __init register_nfs_fs(void)
if (ret < 0)
goto error_2;
#endif
- acl_shrinker = set_shrinker(DEFAULT_SEEKS, nfs_access_cache_shrinker);
+ register_shrinker(&acl_shrinker);
return 0;
#ifdef CONFIG_NFS_V4
@@ -177,8 +180,7 @@ error_0:
*/
void __exit unregister_nfs_fs(void)
{
- if (acl_shrinker != NULL)
- remove_shrinker(acl_shrinker);
+ unregister_shrinker(&acl_shrinker);
#ifdef CONFIG_NFS_V4
unregister_filesystem(&nfs4_fs_type);
nfs_unregister_sysctl();
diff -puN fs/xfs/linux-2.6/xfs_buf.c~mm-clean-up-and-kernelify-shrinker-registration fs/xfs/linux-2.6/xfs_buf.c
--- a/fs/xfs/linux-2.6/xfs_buf.c~mm-clean-up-and-kernelify-shrinker-registration
+++ a/fs/xfs/linux-2.6/xfs_buf.c
@@ -35,10 +35,13 @@
#include <linux/freezer.h>
static kmem_zone_t *xfs_buf_zone;
-static struct shrinker *xfs_buf_shake;
STATIC int xfsbufd(void *);
STATIC int xfsbufd_wakeup(int, gfp_t);
STATIC void xfs_buf_delwri_queue(xfs_buf_t *, int);
+static struct shrinker xfs_buf_shake = {
+ .shrink = xfsbufd_wakeup,
+ .seeks = DEFAULT_SEEKS,
+};
static struct workqueue_struct *xfslogd_workqueue;
struct workqueue_struct *xfsdatad_workqueue;
@@ -1837,14 +1840,9 @@ xfs_buf_init(void)
if (!xfsdatad_workqueue)
goto out_destroy_xfslogd_workqueue;
- xfs_buf_shake = set_shrinker(DEFAULT_SEEKS, xfsbufd_wakeup);
- if (!xfs_buf_shake)
- goto out_destroy_xfsdatad_workqueue;
-
+ register_shrinker(&xfs_buf_shake);
return 0;
- out_destroy_xfsdatad_workqueue:
- destroy_workqueue(xfsdatad_workqueue);
out_destroy_xfslogd_workqueue:
destroy_workqueue(xfslogd_workqueue);
out_free_buf_zone:
@@ -1859,7 +1857,7 @@ xfs_buf_init(void)
void
xfs_buf_terminate(void)
{
- remove_shrinker(xfs_buf_shake);
+ unregister_shrinker(&xfs_buf_shake);
destroy_workqueue(xfsdatad_workqueue);
destroy_workqueue(xfslogd_workqueue);
kmem_zone_destroy(xfs_buf_zone);
diff -puN fs/xfs/quota/xfs_qm.c~mm-clean-up-and-kernelify-shrinker-registration fs/xfs/quota/xfs_qm.c
--- a/fs/xfs/quota/xfs_qm.c~mm-clean-up-and-kernelify-shrinker-registration
+++ a/fs/xfs/quota/xfs_qm.c
@@ -62,7 +62,6 @@ uint ndquot;
kmem_zone_t *qm_dqzone;
kmem_zone_t *qm_dqtrxzone;
-static struct shrinker *xfs_qm_shaker;
static cred_t xfs_zerocr;
static xfs_inode_t xfs_zeroino;
@@ -79,6 +78,11 @@ STATIC int xfs_qm_init_quotainos(xfs_mou
STATIC int xfs_qm_init_quotainfo(xfs_mount_t *);
STATIC int xfs_qm_shake(int, gfp_t);
+static struct shrinker xfs_qm_shaker = {
+ .shrink = xfs_qm_shake,
+ .seeks = DEFAULT_SEEKS,
+};
+
#ifdef DEBUG
extern mutex_t qcheck_lock;
#endif
@@ -150,7 +154,7 @@ xfs_Gqm_init(void)
} else
xqm->qm_dqzone = qm_dqzone;
- xfs_qm_shaker = set_shrinker(DEFAULT_SEEKS, xfs_qm_shake);
+ register_shrinker(&xfs_qm_shaker);
/*
* The t_dqinfo portion of transactions.
@@ -182,7 +186,7 @@ xfs_qm_destroy(
ASSERT(xqm != NULL);
ASSERT(xqm->qm_nrefs == 0);
- remove_shrinker(xfs_qm_shaker);
+ unregister_shrinker(&xfs_qm_shaker);
hsize = xqm->qm_dqhashmask + 1;
for (i = 0; i < hsize; i++) {
xfs_qm_list_destroy(&(xqm->qm_usr_dqhtable[i]));
diff -puN include/linux/mm.h~mm-clean-up-and-kernelify-shrinker-registration include/linux/mm.h
--- a/include/linux/mm.h~mm-clean-up-and-kernelify-shrinker-registration
+++ a/include/linux/mm.h
@@ -810,27 +810,31 @@ extern unsigned long do_mremap(unsigned
unsigned long flags, unsigned long new_addr);
/*
- * Prototype to add a shrinker callback for ageable caches.
- *
- * These functions are passed a count `nr_to_scan' and a gfpmask. They should
- * scan `nr_to_scan' objects, attempting to free them.
+ * A callback you can register to apply pressure to ageable caches.
*
- * The callback must return the number of objects which remain in the cache.
+ * 'shrink' is passed a count 'nr_to_scan' and a 'gfpmask'. It should
+ * look through the least-recently-used 'nr_to_scan' entries and
+ * attempt to free them up. It should return the number of objects
+ * which remain in the cache. If it returns -1, it means it cannot do
+ * any scanning at this time (eg. there is a risk of deadlock).
*
- * The callback will be passed nr_to_scan == 0 when the VM is querying the
- * cache size, so a fastpath for that case is appropriate.
- */
-typedef int (*shrinker_t)(int nr_to_scan, gfp_t gfp_mask);
-
-/*
- * Add an aging callback. The int is the number of 'seeks' it takes
- * to recreate one of the objects that these functions age.
+ * The 'gfpmask' refers to the allocation we are currently trying to
+ * fulfil.
+ *
+ * Note that 'shrink' will be passed nr_to_scan == 0 when the VM is
+ * querying the cache size, so a fastpath for that case is appropriate.
*/
-
-#define DEFAULT_SEEKS 2
-struct shrinker;
-extern struct shrinker *set_shrinker(int, shrinker_t);
-extern void remove_shrinker(struct shrinker *shrinker);
+struct shrinker {
+ int (*shrink)(int nr_to_scan, gfp_t gfp_mask);
+ int seeks; /* seeks to recreate an obj */
+
+ /* These are for internal use */
+ struct list_head list;
+ long nr; /* objs pending delete */
+};
+#define DEFAULT_SEEKS 2 /* A good number if you don't know better. */
+extern void register_shrinker(struct shrinker *);
+extern void unregister_shrinker(struct shrinker *);
/*
* Some shared mappigns will want the pages marked read-only
diff -puN mm/vmscan.c~mm-clean-up-and-kernelify-shrinker-registration mm/vmscan.c
--- a/mm/vmscan.c~mm-clean-up-and-kernelify-shrinker-registration
+++ a/mm/vmscan.c
@@ -70,17 +70,6 @@ struct scan_control {
int order;
};
-/*
- * The list of shrinker callbacks used by to apply pressure to
- * ageable caches.
- */
-struct shrinker {
- shrinker_t shrinker;
- struct list_head list;
- int seeks; /* seeks to recreate an obj */
- long nr; /* objs pending delete */
-};
-
#define lru_to_page(_head) (list_entry((_head)->prev, struct page, lru))
#ifdef ARCH_HAS_PREFETCH
@@ -123,34 +112,25 @@ static DECLARE_RWSEM(shrinker_rwsem);
/*
* Add a shrinker callback to be called from the vm
*/
-struct shrinker *set_shrinker(int seeks, shrinker_t theshrinker)
+void register_shrinker(struct shrinker *shrinker)
{
- struct shrinker *shrinker;
-
- shrinker = kmalloc(sizeof(*shrinker), GFP_KERNEL);
- if (shrinker) {
- shrinker->shrinker = theshrinker;
- shrinker->seeks = seeks;
- shrinker->nr = 0;
- down_write(&shrinker_rwsem);
- list_add_tail(&shrinker->list, &shrinker_list);
- up_write(&shrinker_rwsem);
- }
- return shrinker;
+ shrinker->nr = 0;
+ down_write(&shrinker_rwsem);
+ list_add_tail(&shrinker->list, &shrinker_list);
+ up_write(&shrinker_rwsem);
}
-EXPORT_SYMBOL(set_shrinker);
+EXPORT_SYMBOL(register_shrinker);
/*
* Remove one
*/
-void remove_shrinker(struct shrinker *shrinker)
+void unregister_shrinker(struct shrinker *shrinker)
{
down_write(&shrinker_rwsem);
list_del(&shrinker->list);
up_write(&shrinker_rwsem);
- kfree(shrinker);
}
-EXPORT_SYMBOL(remove_shrinker);
+EXPORT_SYMBOL(unregister_shrinker);
#define SHRINK_BATCH 128
/*
@@ -187,7 +167,7 @@ unsigned long shrink_slab(unsigned long
list_for_each_entry(shrinker, &shrinker_list, list) {
unsigned long long delta;
unsigned long total_scan;
- unsigned long max_pass = (*shrinker->shrinker)(0, gfp_mask);
+ unsigned long max_pass = (*shrinker->shrink)(0, gfp_mask);
delta = (4 * scanned) / shrinker->seeks;
delta *= max_pass;
@@ -215,8 +195,8 @@ unsigned long shrink_slab(unsigned long
int shrink_ret;
int nr_before;
- nr_before = (*shrinker->shrinker)(0, gfp_mask);
- shrink_ret = (*shrinker->shrinker)(this_scan, gfp_mask);
+ nr_before = (*shrinker->shrink)(0, gfp_mask);
+ shrink_ret = (*shrinker->shrink)(this_scan, gfp_mask);
if (shrink_ret == -1)
break;
if (shrink_ret < nr_before)
_
Patches currently in -mm which might be from rusty@xxxxxxxxxxxxxxx are
vmi-paravirt-ops-bugfix-for-2621.patch
git-kbuild.patch
git-net.patch
allow-per-cpu-variables-to-be-page-aligned.patch
xfs-clean-up-shrinker-games.patch
mm-clean-up-and-kernelify-shrinker-registration.patch
array_size-check-for-type.patch
array_size-check-for-type-uml-fix.patch
module-use-krealloc.patch
extend-print_symbol-capability.patch
extend-print_symbol-capability-fix.patch
futex-restartable-futex_wait.patch
futex-restartable-futex_wait-fix.patch
add-ability-to-keep-track-of-callers-of-symbol_getput.patch
add-ability-to-keep-track-of-callers-of-symbol_getput-update.patch
update-mtd-use-of-symbol_getput.patch
update-dvb-use-of-symbol_getput.patch
simplify-module_get_kallsym-by-dropping-length-arg.patch
fix-race-between-rmmod-and-cat-proc-kallsyms.patch
simplify-kallsyms_lookup.patch
fix-race-between-cat-proc-wchan-and-rmmod-et-al.patch
fix-race-between-cat-proc-slab_allocators-and-rmmod.patch
____call_usermodehelper-dont-flush_signals.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
