diff options
author | Jeff Moyer <jmoyer@redhat.com> | 2009-04-21 01:25:04 -0400 |
---|---|---|
committer | Jens Axboe <jens.axboe@oracle.com> | 2009-04-22 02:35:11 -0400 |
commit | 4d00aa47e2337dcfe2d8a7215dbde3765b507167 (patch) | |
tree | 069f0c202e6a3f3017b0a8b4320b31172bcc1071 /block/cfq-iosched.c | |
parent | b759113499d6c7cb75fab04f56772579308bc0f8 (diff) |
cfq-iosched: make seek_mean converge more quickly
Right now, depending on the first sector to which a process issues I/O,
the seek time may start out way out of whack. So make sure we start
with 0 sectors in seek, instead of the offset of the first request
issued.
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'block/cfq-iosched.c')
-rw-r--r-- | block/cfq-iosched.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 0d3b70de3d80..0eb4aff9df68 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c | |||
@@ -1908,7 +1908,9 @@ cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_io_context *cic, | |||
1908 | sector_t sdist; | 1908 | sector_t sdist; |
1909 | u64 total; | 1909 | u64 total; |
1910 | 1910 | ||
1911 | if (cic->last_request_pos < rq->sector) | 1911 | if (!cic->last_request_pos) |
1912 | sdist = 0; | ||
1913 | else if (cic->last_request_pos < rq->sector) | ||
1912 | sdist = rq->sector - cic->last_request_pos; | 1914 | sdist = rq->sector - cic->last_request_pos; |
1913 | else | 1915 | else |
1914 | sdist = cic->last_request_pos - rq->sector; | 1916 | sdist = cic->last_request_pos - rq->sector; |