|| ||Jeff Moyer <firstname.lastname@example.org> |
|| ||email@example.com, firstname.lastname@example.org |
|| ||[PATCH 0/3 v5][RFC] ext3/4: enhance fsync performance when using CFQ |
|| ||Tue, 22 Jun 2010 17:34:59 -0400|
|| ||email@example.com, firstname.lastname@example.org|
|| ||Article, Thread
Running iozone with the fsync flag, or fs_mark, the performance of CFQ is
far worse than that of deadline for enterprise class storage when dealing
with file sizes of 8MB or less. I used the following command line as a
representative test case:
fs_mark -S 1 -D 10000 -N 100000 -d /mnt/test/fs_mark -s 65536 -t 1 -w 4096 -F
When run using the deadline I/O scheduler, an average of the first 5 numbers
will give you 448.4 files / second. CFQ will yield only 106.7. With
this patch series applied (and the two patches I sent yesterday), CFQ now
achieves 462.5 files / second.
This patch set is still an RFC. I'd like to make it perform better when
there is a competing sequential reader present. For now, I've addressed
the concerns voiced about the previous posting.
Review and testing would be greatly appreciated.
New from the last round:
- removed the think time calculation I added for the sync-noidle service tree
- replaced above with a suggestion from Vivek to only guard against currently
active sequential readers when determining if we can preempt the sync-noidle
- bug fixes
Over all, I think it's simpler now thanks to the suggestions from Jens and
[PATCH 1/3] block: Implement a blk_yield function to voluntarily give up the I/O scheduler.
[PATCH 2/3] jbd: yield the device queue when waiting for commits
[PATCH 3/3] jbd2: yield the device queue when waiting for journal commits
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to email@example.com
More majordomo info at http://vger.kernel.org/majordomo-info.html