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| author | Jens Axboe <jens.axboe@oracle.com> | 2006-10-31 14:21:55 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-10-31 08:12:45 -0800 |
| commit | 5fccbf61be2a7f32d2002b04afca4c5009612a58 (patch) | |
| tree | 1a7a09dcbf4b518cf5d695fa8dbe41e21a1ab413 /block/cfq-iosched.c | |
| parent | eafa6cb18ec7e5424ce54017b5ce6d11dff58b79 (diff) | |
| download | lwn-5fccbf61be2a7f32d2002b04afca4c5009612a58.tar.gz lwn-5fccbf61be2a7f32d2002b04afca4c5009612a58.zip | |
[PATCH] CFQ: request <-> request merging rr_list fixup
In very rare circumstances would we be pruning a merged request and at
the same time delete the implicated cfqq from the rr_list, and not readd
it when the merged request got added. This could cause io stalls until
that process issued io again.
Fix it up by putting the rr_list add handling into cfq_add_rq_rb(),
identical to how pruning is handled in cfq_del_rq_rb(). This fixes a
hang reproducible with fsx-linux.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'block/cfq-iosched.c')
| -rw-r--r-- | block/cfq-iosched.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 25c4e7ed0d00..1d9c3c70a9a0 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -456,6 +456,9 @@ static void cfq_add_rq_rb(struct request *rq) */ while ((__alias = elv_rb_add(&cfqq->sort_list, rq)) != NULL) cfq_dispatch_insert(cfqd->queue, __alias); + + if (!cfq_cfqq_on_rr(cfqq)) + cfq_add_cfqq_rr(cfqd, cfqq); } static inline void @@ -1652,9 +1655,6 @@ static void cfq_insert_request(request_queue_t *q, struct request *rq) cfq_add_rq_rb(rq); - if (!cfq_cfqq_on_rr(cfqq)) - cfq_add_cfqq_rr(cfqd, cfqq); - list_add_tail(&rq->queuelist, &cfqq->fifo); cfq_rq_enqueued(cfqd, cfqq, rq); |