diff options
| -rw-r--r-- | fs/dcache.c | 24 |
1 files changed, 10 insertions, 14 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index 920c87720385..bde6057c5df6 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -381,20 +381,17 @@ restart: * Throw away a dentry - free the inode, dput the parent. This requires that * the LRU list has already been removed. * - * If prune_parents is true, try to prune ancestors as well. + * Try to prune ancestors as well. This is necessary to prevent + * quadratic behavior of shrink_dcache_parent(), but is also expected + * to be beneficial in reducing dentry cache fragmentation. * * Called with dcache_lock, drops it and then regains. * Called with dentry->d_lock held, drops it. */ -static void prune_one_dentry(struct dentry * dentry, int prune_parents) +static void prune_one_dentry(struct dentry * dentry) { __d_drop(dentry); dentry = d_kill(dentry); - if (!prune_parents) { - dput(dentry); - spin_lock(&dcache_lock); - return; - } /* * Prune ancestors. Locking is simpler than in dput(), @@ -422,7 +419,6 @@ static void prune_one_dentry(struct dentry * dentry, int prune_parents) * @count: number of entries to try and free * @sb: if given, ignore dentries for other superblocks * which are being unmounted. - * @prune_parents: if true, try to prune ancestors as well in one go * * Shrink the dcache. This is done when we need * more memory, or simply when we need to unmount @@ -433,7 +429,7 @@ static void prune_one_dentry(struct dentry * dentry, int prune_parents) * all the dentries are in use. */ -static void prune_dcache(int count, struct super_block *sb, int prune_parents) +static void prune_dcache(int count, struct super_block *sb) { spin_lock(&dcache_lock); for (; count ; count--) { @@ -493,7 +489,7 @@ static void prune_dcache(int count, struct super_block *sb, int prune_parents) * without taking the s_umount lock (I already hold it). */ if (sb && dentry->d_sb == sb) { - prune_one_dentry(dentry, prune_parents); + prune_one_dentry(dentry); continue; } /* @@ -508,7 +504,7 @@ static void prune_dcache(int count, struct super_block *sb, int prune_parents) s_umount = &dentry->d_sb->s_umount; if (down_read_trylock(s_umount)) { if (dentry->d_sb->s_root != NULL) { - prune_one_dentry(dentry, prune_parents); + prune_one_dentry(dentry); up_read(s_umount); continue; } @@ -579,7 +575,7 @@ repeat: spin_unlock(&dentry->d_lock); continue; } - prune_one_dentry(dentry, 1); + prune_one_dentry(dentry); cond_resched_lock(&dcache_lock); goto repeat; } @@ -858,7 +854,7 @@ void shrink_dcache_parent(struct dentry * parent) int found; while ((found = select_parent(parent)) != 0) - prune_dcache(found, parent->d_sb, 1); + prune_dcache(found, parent->d_sb); } /* @@ -878,7 +874,7 @@ static int shrink_dcache_memory(int nr, gfp_t gfp_mask) if (nr) { if (!(gfp_mask & __GFP_FS)) return -1; - prune_dcache(nr, NULL, 1); + prune_dcache(nr, NULL); } return (dentry_stat.nr_unused / 100) * sysctl_vfs_cache_pressure; } |