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| author | Tejun Heo <tj@kernel.org> | 2015-08-18 14:54:58 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2015-08-18 15:49:15 -0700 |
| commit | 95e5d6f62693f27d9011ec307eb32c6126314ea3 (patch) | |
| tree | 4b30989af492f003a7bdb9534951f47f5341273d /block/cfq-iosched.c | |
| parent | 4ebc1c61d6185604c97fd0b0355ab668052044ab (diff) | |
| download | linux-0-day-95e5d6f62693f27d9011ec307eb32c6126314ea3.tar.gz linux-0-day-95e5d6f62693f27d9011ec307eb32c6126314ea3.tar.xz | |
cfq-iosched: fix async oom queue handling
Async cfqq's (cfq_queue's) are shared across cfq_data. When
cfq_get_queue() obtains a new queue from cfq_find_alloc_queue(), it
stashes the pointer in cfq_data and reuses it from then on; however,
the function doesn't consider that cfq_find_alloc_queue() may return
the oom_cfqq under memory pressure and installs the returned queue
unconditionally.
If the oom_cfqq is installed as an async cfqq, cfq_set_request() will
continue calling cfq_get_queue() hoping to replace it with a proper
queue; however, cfq_get_queue() will keep returning the cached queue
for the slot - the oom_cfqq.
Fix it by skipping caching if the queue is the oom one.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/cfq-iosched.c')
| -rw-r--r-- | block/cfq-iosched.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index e91093d0c0eb3..baf0b706169da 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -3751,7 +3751,7 @@ cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic, /* * pin the queue now that it's allocated, scheduler exit will prune it */ - if (!is_sync) { + if (!is_sync && cfqq != &cfqd->oom_cfqq) { cfqq->ref++; *async_cfqq = cfqq; } |