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| author | Shaohua Li <shli@kernel.org> | 2013-12-31 04:38:50 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2014-01-30 20:57:25 +0100 |
| commit | f0276924fa35a3607920a58cf5d878212824b951 (patch) | |
| tree | 5759cef09f3ba6b2f206ace779fef298a8b9d7be /block/blk.h | |
| parent | percpu_ida: fix a live lock (diff) | |
| download | linux-f0276924fa35a3607920a58cf5d878212824b951.tar.xz linux-f0276924fa35a3607920a58cf5d878212824b951.zip | |
blk-mq: Don't reserve a tag for flush request
Reserving a tag (request) for flush to avoid dead lock is a overkill. A
tag is valuable resource. We can track the number of flush requests and
disallow having too many pending flush requests allocated. With this
patch, blk_mq_alloc_request_pinned() could do a busy nop (but not a dead
loop) if too many pending requests are allocated and new flush request
is allocated. But this should not be a problem, too many pending flush
requests are very rare case.
I verified this can fix the deadlock caused by too many pending flush
requests.
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk.h')
0 files changed, 0 insertions, 0 deletions