From 1403390d8366c717139cab26b8e94d943915fa12 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Mon, 17 Jul 2017 09:37:12 -0400 Subject: NFS: Reduce lock contention in nfs_try_to_update_request() Micro-optimisation to move the lockless check into the for(;;) loop. Signed-off-by: Trond Myklebust --- fs/nfs/write.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 06e150c4e315..bb019096c331 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1097,13 +1097,12 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode, unsigned int end; int error; - if (!PagePrivate(page)) - return NULL; - end = offset + bytes; - spin_lock(&inode->i_lock); for (;;) { + if (!(PagePrivate(page) || PageSwapCache(page))) + return NULL; + spin_lock(&inode->i_lock); req = nfs_page_find_head_request_locked(NFS_I(inode), page); if (req == NULL) goto out_unlock; @@ -1132,7 +1131,6 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode, nfs_release_request(req); if (error != 0) goto out_err; - spin_lock(&inode->i_lock); } /* Okay, the request matches. Update the region */ -- cgit v1.2.3-55-g7522