diff options
| author | NeilBrown <neilb@suse.de> | 2014-09-24 11:28:32 +1000 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@primarydata.com> | 2014-09-25 08:25:38 -0400 |
| commit | 353db7966288a2f18da22438aeec2b4862c0b241 (patch) | |
| tree | 959b0fe5a246747af6db55bb7652d4d35b738ba8 /fs/nfs/write.c | |
| parent | 9590544694becc64f4874963dbfc4b4d391024b7 (diff) | |
NFS: avoid waiting at all in nfs_release_page when congested.
If nfs_release_page() is called on a sequence of pages which are all
in the same file which is blocked on COMMIT, each page could
contribute a 1 second delay which could be come excessive. I have
seen delays of as much as 208 seconds.
To keep the delay to one second, mark the bdi as write-congested
if the commit didn't finished. Once it does finish, the
write-congested flag will be cleared by nfs_commit_release_pages().
With this, the longest total delay in try_to_free_pages that I have
seen is under 3 seconds. With no waiting in nfs_release_page at all
I have seen delays of nearly 1.5 seconds.
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Diffstat (limited to 'fs/nfs/write.c')
| -rw-r--r-- | fs/nfs/write.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/nfs/write.c b/fs/nfs/write.c index c063a4e70354..12493846a2d3 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1611,6 +1611,7 @@ static void nfs_commit_release_pages(struct nfs_commit_data *data) struct nfs_page *req; int status = data->task.tk_status; struct nfs_commit_info cinfo; + struct nfs_server *nfss; while (!list_empty(&data->pages)) { req = nfs_list_entry(data->pages.next); @@ -1644,6 +1645,10 @@ static void nfs_commit_release_pages(struct nfs_commit_data *data) next: nfs_unlock_and_release_request(req); } + nfss = NFS_SERVER(data->inode); + if (atomic_long_read(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH) + clear_bdi_congested(&nfss->backing_dev_info, BLK_RW_ASYNC); + nfs_init_cinfo(&cinfo, data->inode, data->dreq); if (atomic_dec_and_test(&cinfo.mds->rpcs_out)) nfs_commit_clear_lock(NFS_I(data->inode)); |