Fix some bugs spotted by Andrea Arcangeli <andrea@suse.de>
- When we added /proc/sys/vm/vfs_cache_pressure we forgot to allow it to
tune the dquot and mbcache slabs as well.
- Reduce lock contention in shrink_dqcache_memory().
- Use dqstats.free_dquots in shrink_dqcache_memory(): this is the count of
reclaimable objects.
- Export sysctl_vfs_cache_pressure to GPL modules for mbcache.o
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/fs/dcache.c | 1 +
25-akpm/fs/dquot.c | 12 +++++-------
25-akpm/fs/mbcache.c | 2 +-
3 files changed, 7 insertions(+), 8 deletions(-)
diff -puN fs/dquot.c~slab-shrinkers-use-vfs_cache_pressure fs/dquot.c
--- 25/fs/dquot.c~slab-shrinkers-use-vfs_cache_pressure 2005-03-18 01:07:25.000000000 -0800
+++ 25-akpm/fs/dquot.c 2005-03-18 01:07:25.000000000 -0800
@@ -505,14 +505,12 @@ static void prune_dqcache(int count)
static int shrink_dqcache_memory(int nr, unsigned int gfp_mask)
{
- int ret;
-
- spin_lock(&dq_list_lock);
- if (nr)
+ if (nr) {
+ spin_lock(&dq_list_lock);
prune_dqcache(nr);
- ret = dqstats.allocated_dquots;
- spin_unlock(&dq_list_lock);
- return ret;
+ spin_unlock(&dq_list_lock);
+ }
+ return (dqstats.free_dquots / 100) * sysctl_vfs_cache_pressure;
}
/*
diff -puN fs/mbcache.c~slab-shrinkers-use-vfs_cache_pressure fs/mbcache.c
--- 25/fs/mbcache.c~slab-shrinkers-use-vfs_cache_pressure 2005-03-18 01:07:25.000000000 -0800
+++ 25-akpm/fs/mbcache.c 2005-03-18 01:07:25.000000000 -0800
@@ -225,7 +225,7 @@ mb_cache_shrink_fn(int nr_to_scan, unsig
e_lru_list), gfp_mask);
}
out:
- return count;
+ return (count / 100) * sysctl_vfs_cache_pressure;
}
diff -puN fs/dcache.c~slab-shrinkers-use-vfs_cache_pressure fs/dcache.c
--- 25/fs/dcache.c~slab-shrinkers-use-vfs_cache_pressure 2005-03-18 01:34:08.000000000 -0800
+++ 25-akpm/fs/dcache.c 2005-03-18 01:34:23.000000000 -0800
@@ -36,6 +36,7 @@
/* #define DCACHE_DEBUG 1 */
int sysctl_vfs_cache_pressure = 100;
+EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure);
__cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lock);
seqlock_t rename_lock __cacheline_aligned_in_smp = SEQLOCK_UNLOCKED;
_