Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755988Ab2K0XPW (ORCPT ); Tue, 27 Nov 2012 18:15:22 -0500 Received: from ipmail04.adl6.internode.on.net ([150.101.137.141]:26299 "EHLO ipmail04.adl6.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755858Ab2K0XPT (ORCPT ); Tue, 27 Nov 2012 18:15:19 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AicGABZJtVB5LIZ7/2dsb2JhbABFi320IRdzgh4BAQUnLyMQCBgxOQMbGYgMv3WQewOmRYME From: Dave Chinner To: glommer@parallels.com Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, xfs@oss.sgi.com Subject: [PATCH 02/19] dentry: move to per-sb LRU locks Date: Wed, 28 Nov 2012 10:14:29 +1100 Message-Id: <1354058086-27937-3-git-send-email-david@fromorbit.com> X-Mailer: git-send-email 1.7.10 In-Reply-To: <1354058086-27937-1-git-send-email-david@fromorbit.com> References: <1354058086-27937-1-git-send-email-david@fromorbit.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5827 Lines: 184 From: Dave Chinner With the dentry LRUs being per-sb structures, there is no real need for a global dentry_lru_lock. The locking can be made more fine-grained by moving to a per-sb LRU lock, isolating the LRU operations of different filesytsems completely from each other. Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig --- fs/dcache.c | 37 ++++++++++++++++++------------------- fs/super.c | 1 + include/linux/fs.h | 4 +++- 3 files changed, 22 insertions(+), 20 deletions(-) diff --git a/fs/dcache.c b/fs/dcache.c index 2fc0daa..e0c97fe 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -48,7 +48,7 @@ * - the dcache hash table * s_anon bl list spinlock protects: * - the s_anon list (see __d_drop) - * dcache_lru_lock protects: + * dentry->d_sb->s_dentry_lru_lock protects: * - the dcache lru lists and counters * d_lock protects: * - d_flags @@ -63,7 +63,7 @@ * Ordering: * dentry->d_inode->i_lock * dentry->d_lock - * dcache_lru_lock + * dentry->d_sb->s_dentry_lru_lock * dcache_hash_bucket lock * s_anon lock * @@ -81,7 +81,6 @@ int sysctl_vfs_cache_pressure __read_mostly = 100; EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure); -static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lru_lock); __cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock); EXPORT_SYMBOL(rename_lock); @@ -320,11 +319,11 @@ static void dentry_unlink_inode(struct dentry * dentry) static void dentry_lru_add(struct dentry *dentry) { if (list_empty(&dentry->d_lru)) { - spin_lock(&dcache_lru_lock); + spin_lock(&dentry->d_sb->s_dentry_lru_lock); list_add(&dentry->d_lru, &dentry->d_sb->s_dentry_lru); dentry->d_sb->s_nr_dentry_unused++; this_cpu_inc(nr_dentry_unused); - spin_unlock(&dcache_lru_lock); + spin_unlock(&dentry->d_sb->s_dentry_lru_lock); } } @@ -342,9 +341,9 @@ static void __dentry_lru_del(struct dentry *dentry) static void dentry_lru_del(struct dentry *dentry) { if (!list_empty(&dentry->d_lru)) { - spin_lock(&dcache_lru_lock); + spin_lock(&dentry->d_sb->s_dentry_lru_lock); __dentry_lru_del(dentry); - spin_unlock(&dcache_lru_lock); + spin_unlock(&dentry->d_sb->s_dentry_lru_lock); } } @@ -359,15 +358,15 @@ static void dentry_lru_prune(struct dentry *dentry) if (dentry->d_flags & DCACHE_OP_PRUNE) dentry->d_op->d_prune(dentry); - spin_lock(&dcache_lru_lock); + spin_lock(&dentry->d_sb->s_dentry_lru_lock); __dentry_lru_del(dentry); - spin_unlock(&dcache_lru_lock); + spin_unlock(&dentry->d_sb->s_dentry_lru_lock); } } static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list) { - spin_lock(&dcache_lru_lock); + spin_lock(&dentry->d_sb->s_dentry_lru_lock); if (list_empty(&dentry->d_lru)) { list_add_tail(&dentry->d_lru, list); dentry->d_sb->s_nr_dentry_unused++; @@ -375,7 +374,7 @@ static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list) } else { list_move_tail(&dentry->d_lru, list); } - spin_unlock(&dcache_lru_lock); + spin_unlock(&dentry->d_sb->s_dentry_lru_lock); } /** @@ -879,14 +878,14 @@ void prune_dcache_sb(struct super_block *sb, int count) LIST_HEAD(tmp); relock: - spin_lock(&dcache_lru_lock); + spin_lock(&sb->s_dentry_lru_lock); while (!list_empty(&sb->s_dentry_lru)) { dentry = list_entry(sb->s_dentry_lru.prev, struct dentry, d_lru); BUG_ON(dentry->d_sb != sb); if (!spin_trylock(&dentry->d_lock)) { - spin_unlock(&dcache_lru_lock); + spin_unlock(&sb->s_dentry_lru_lock); cpu_relax(); goto relock; } @@ -902,11 +901,11 @@ relock: if (!--count) break; } - cond_resched_lock(&dcache_lru_lock); + cond_resched_lock(&sb->s_dentry_lru_lock); } if (!list_empty(&referenced)) list_splice(&referenced, &sb->s_dentry_lru); - spin_unlock(&dcache_lru_lock); + spin_unlock(&sb->s_dentry_lru_lock); shrink_dentry_list(&tmp); } @@ -922,14 +921,14 @@ void shrink_dcache_sb(struct super_block *sb) { LIST_HEAD(tmp); - spin_lock(&dcache_lru_lock); + spin_lock(&sb->s_dentry_lru_lock); while (!list_empty(&sb->s_dentry_lru)) { list_splice_init(&sb->s_dentry_lru, &tmp); - spin_unlock(&dcache_lru_lock); + spin_unlock(&sb->s_dentry_lru_lock); shrink_dentry_list(&tmp); - spin_lock(&dcache_lru_lock); + spin_lock(&sb->s_dentry_lru_lock); } - spin_unlock(&dcache_lru_lock); + spin_unlock(&sb->s_dentry_lru_lock); } EXPORT_SYMBOL(shrink_dcache_sb); diff --git a/fs/super.c b/fs/super.c index 12f1237..21abf02 100644 --- a/fs/super.c +++ b/fs/super.c @@ -182,6 +182,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags) INIT_HLIST_BL_HEAD(&s->s_anon); INIT_LIST_HEAD(&s->s_inodes); INIT_LIST_HEAD(&s->s_dentry_lru); + spin_lock_init(&s->s_dentry_lru_lock); INIT_LIST_HEAD(&s->s_inode_lru); spin_lock_init(&s->s_inode_lru_lock); INIT_LIST_HEAD(&s->s_mounts); diff --git a/include/linux/fs.h b/include/linux/fs.h index b33cfc9..0845283 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1262,7 +1262,9 @@ struct super_block { struct list_head s_files; #endif struct list_head s_mounts; /* list of mounts; _not_ for fs use */ - /* s_dentry_lru, s_nr_dentry_unused protected by dcache.c lru locks */ + + /* s_dentry_lru_lock protects s_dentry_lru and s_nr_dentry_unused */ + spinlock_t s_dentry_lru_lock ____cacheline_aligned_in_smp; struct list_head s_dentry_lru; /* unused dentry lru */ int s_nr_dentry_unused; /* # of dentry on lru */ -- 1.7.10 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/