From 74278da9f70d84d715601fe794567a6d2bfdf078 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Wed, 4 Mar 2015 12:37:22 -0500 Subject: inode: convert inode_sb_list_lock to per-sb The process of reducing contention on per-superblock inode lists starts with moving the locking to match the per-superblock inode list. This takes the global lock out of the picture and reduces the contention problems to within a single filesystem. This doesn't get rid of contention as the locks still have global CPU scope, but it does isolate operations on different superblocks form each other. Signed-off-by: Dave Chinner Signed-off-by: Josef Bacik Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig Tested-by: Dave Chinner --- fs/inode.c | 28 +++++++++++++--------------- 1 file changed, 13 insertions(+), 15 deletions(-) (limited to 'fs/inode.c') diff --git a/fs/inode.c b/fs/inode.c index d30640f7a193..a2de294f6b77 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -28,8 +28,8 @@ * inode->i_state, inode->i_hash, __iget() * Inode LRU list locks protect: * inode->i_sb->s_inode_lru, inode->i_lru - * inode_sb_list_lock protects: - * sb->s_inodes, inode->i_sb_list + * inode->i_sb->s_inode_list_lock protects: + * inode->i_sb->s_inodes, inode->i_sb_list * bdi->wb.list_lock protects: * bdi->wb.b_{dirty,io,more_io,dirty_time}, inode->i_wb_list * inode_hash_lock protects: @@ -37,7 +37,7 @@ * * Lock ordering: * - * inode_sb_list_lock + * inode->i_sb->s_inode_list_lock * inode->i_lock * Inode LRU list locks * @@ -45,7 +45,7 @@ * inode->i_lock * * inode_hash_lock - * inode_sb_list_lock + * inode->i_sb->s_inode_list_lock * inode->i_lock * * iunique_lock @@ -57,8 +57,6 @@ static unsigned int i_hash_shift __read_mostly; static struct hlist_head *inode_hashtable __read_mostly; static __cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_hash_lock); -__cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_sb_list_lock); - /* * Empty aops. Can be used for the cases where the user does not * define any of the address_space operations. @@ -426,18 +424,18 @@ static void inode_lru_list_del(struct inode *inode) */ void inode_sb_list_add(struct inode *inode) { - spin_lock(&inode_sb_list_lock); + spin_lock(&inode->i_sb->s_inode_list_lock); list_add(&inode->i_sb_list, &inode->i_sb->s_inodes); - spin_unlock(&inode_sb_list_lock); + spin_unlock(&inode->i_sb->s_inode_list_lock); } EXPORT_SYMBOL_GPL(inode_sb_list_add); static inline void inode_sb_list_del(struct inode *inode) { if (!list_empty(&inode->i_sb_list)) { - spin_lock(&inode_sb_list_lock); + spin_lock(&inode->i_sb->s_inode_list_lock); list_del_init(&inode->i_sb_list); - spin_unlock(&inode_sb_list_lock); + spin_unlock(&inode->i_sb->s_inode_list_lock); } } @@ -594,7 +592,7 @@ void evict_inodes(struct super_block *sb) struct inode *inode, *next; LIST_HEAD(dispose); - spin_lock(&inode_sb_list_lock); + spin_lock(&sb->s_inode_list_lock); list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) { if (atomic_read(&inode->i_count)) continue; @@ -610,7 +608,7 @@ void evict_inodes(struct super_block *sb) spin_unlock(&inode->i_lock); list_add(&inode->i_lru, &dispose); } - spin_unlock(&inode_sb_list_lock); + spin_unlock(&sb->s_inode_list_lock); dispose_list(&dispose); } @@ -631,7 +629,7 @@ int invalidate_inodes(struct super_block *sb, bool kill_dirty) struct inode *inode, *next; LIST_HEAD(dispose); - spin_lock(&inode_sb_list_lock); + spin_lock(&sb->s_inode_list_lock); list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) { spin_lock(&inode->i_lock); if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) { @@ -654,7 +652,7 @@ int invalidate_inodes(struct super_block *sb, bool kill_dirty) spin_unlock(&inode->i_lock); list_add(&inode->i_lru, &dispose); } - spin_unlock(&inode_sb_list_lock); + spin_unlock(&sb->s_inode_list_lock); dispose_list(&dispose); @@ -890,7 +888,7 @@ struct inode *new_inode(struct super_block *sb) { struct inode *inode; - spin_lock_prefetch(&inode_sb_list_lock); + spin_lock_prefetch(&sb->s_inode_list_lock); inode = new_inode_pseudo(sb); if (inode) -- cgit v1.2.3 From c7f5408493aeb01532927b2276316797a03ed6ee Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Wed, 4 Mar 2015 14:07:22 -0500 Subject: inode: rename i_wb_list to i_io_list There's a small consistency problem between the inode and writeback naming. Writeback calls the "for IO" inode queues b_io and b_more_io, but the inode calls these the "writeback list" or i_wb_list. This makes it hard to an new "under writeback" list to the inode, or call it an "under IO" list on the bdi because either way we'll have writeback on IO and IO on writeback and it'll just be confusing. I'm getting confused just writing this! So, rename the inode "for IO" list variable to i_io_list so we can add a new "writeback list" in a subsequent patch. Signed-off-by: Dave Chinner Signed-off-by: Josef Bacik Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig Tested-by: Dave Chinner --- fs/inode.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'fs/inode.c') diff --git a/fs/inode.c b/fs/inode.c index a2de294f6b77..f09148e07198 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -31,7 +31,7 @@ * inode->i_sb->s_inode_list_lock protects: * inode->i_sb->s_inodes, inode->i_sb_list * bdi->wb.list_lock protects: - * bdi->wb.b_{dirty,io,more_io,dirty_time}, inode->i_wb_list + * bdi->wb.b_{dirty,io,more_io,dirty_time}, inode->i_io_list * inode_hash_lock protects: * inode_hashtable, inode->i_hash * @@ -357,7 +357,7 @@ void inode_init_once(struct inode *inode) memset(inode, 0, sizeof(*inode)); INIT_HLIST_NODE(&inode->i_hash); INIT_LIST_HEAD(&inode->i_devices); - INIT_LIST_HEAD(&inode->i_wb_list); + INIT_LIST_HEAD(&inode->i_io_list); INIT_LIST_HEAD(&inode->i_lru); address_space_init_once(&inode->i_data); i_size_ordered_init(inode); @@ -525,8 +525,8 @@ static void evict(struct inode *inode) BUG_ON(!(inode->i_state & I_FREEING)); BUG_ON(!list_empty(&inode->i_lru)); - if (!list_empty(&inode->i_wb_list)) - inode_wb_list_del(inode); + if (!list_empty(&inode->i_io_list)) + inode_io_list_del(inode); inode_sb_list_del(inode); -- cgit v1.2.3 From ac05fbb40062411ea1b722aa2cede7feaa94f1b4 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Wed, 4 Mar 2015 16:52:52 -0500 Subject: inode: don't softlockup when evicting inodes On a box with a lot of ram (148gb) I can make the box softlockup after running an fs_mark job that creates hundreds of millions of empty files. This is because we never generate enough memory pressure to keep the number of inodes on our unused list low, so when we go to unmount we have to evict ~100 million inodes. This makes one processor a very unhappy person, so add a cond_resched() in dispose_list() and if we need a resched when processing the s_inodes list do that and run dispose_list() on what we've currently culled. Thanks, Signed-off-by: Josef Bacik Reviewed-by: Jan Kara --- fs/inode.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'fs/inode.c') diff --git a/fs/inode.c b/fs/inode.c index f09148e07198..78a17b8859e1 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -575,6 +575,7 @@ static void dispose_list(struct list_head *head) list_del_init(&inode->i_lru); evict(inode); + cond_resched(); } } @@ -592,6 +593,7 @@ void evict_inodes(struct super_block *sb) struct inode *inode, *next; LIST_HEAD(dispose); +again: spin_lock(&sb->s_inode_list_lock); list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) { if (atomic_read(&inode->i_count)) @@ -607,6 +609,18 @@ void evict_inodes(struct super_block *sb) inode_lru_list_del(inode); spin_unlock(&inode->i_lock); list_add(&inode->i_lru, &dispose); + + /* + * We can have a ton of inodes to evict at unmount time given + * enough memory, check to see if we need to go to sleep for a + * bit so we don't livelock. + */ + if (need_resched()) { + spin_unlock(&sb->s_inode_list_lock); + cond_resched(); + dispose_list(&dispose); + goto again; + } } spin_unlock(&sb->s_inode_list_lock); -- cgit v1.2.3