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| author | Corrado Zoccolo <czoccolo@gmail.com> | 2010-09-20 15:24:50 +0200 |
|---|---|---|
| committer | Jens Axboe <jaxboe@fusionio.com> | 2010-09-20 15:24:50 +0200 |
| commit | 749ef9f8423054e326f3a246327ed2db4b6d395f (patch) | |
| tree | 388df763e4e731f5d9b4d8dcaedca641521571e3 /fs/jbd | |
| parent | do_mounts: only enable PARTUUID for CONFIG_BLOCK (diff) | |
| download | linux-749ef9f8423054e326f3a246327ed2db4b6d395f.tar.xz linux-749ef9f8423054e326f3a246327ed2db4b6d395f.zip | |
cfq: improve fsync performance for small files
Fsync performance for small files achieved by cfq on high-end disks is
lower than what deadline can achieve, due to idling introduced between
the sync write happening in process context and the journal commit.
Moreover, when competing with a sequential reader, a process writing
small files and fsync-ing them is starved.
This patch fixes the two problems by:
- marking journal commits as WRITE_SYNC, so that they get the REQ_NOIDLE
flag set,
- force all queues that have REQ_NOIDLE requests to be put in the noidle
tree.
Having the queue associated to the fsync-ing process and the one associated
to journal commits in the noidle tree allows:
- switching between them without idling,
- fairness vs. competing idling queues, since they will be serviced only
after the noidle tree expires its slice.
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Tested-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Corrado Zoccolo <czoccolo@gmail.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'fs/jbd')
| -rw-r--r-- | fs/jbd/commit.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c index 95d8c11c929e..3f030e9efea6 100644 --- a/fs/jbd/commit.c +++ b/fs/jbd/commit.c @@ -318,7 +318,7 @@ void journal_commit_transaction(journal_t *journal) int first_tag = 0; int tag_flag; int i; - int write_op = WRITE; + int write_op = WRITE_SYNC; /* * First job: lock down the current transaction and wait for |