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| author | Trond Myklebust | 2017-07-17 15:37:12 +0200 |
|---|---|---|
| committer | Trond Myklebust | 2017-08-15 17:54:46 +0200 |
| commit | 1403390d8366c717139cab26b8e94d943915fa12 (patch) | |
| tree | 4a254482b5f730f0927b88c0fafca3361b7f9235 | |
| parent | NFS: Reduce lock contention in nfs_page_find_head_request() (diff) | |
| download | kernel-qcow2-linux-1403390d8366c717139cab26b8e94d943915fa12.tar.gz kernel-qcow2-linux-1403390d8366c717139cab26b8e94d943915fa12.tar.xz kernel-qcow2-linux-1403390d8366c717139cab26b8e94d943915fa12.zip | |
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 <trond.myklebust@primarydata.com>
| -rw-r--r-- | fs/nfs/write.c | 8 |
1 files 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 */ |