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| author |   Shaohua Li <shli@fb.com> | 2015-01-23 14:18:00 -0700 |
|---|---|---|
| committer |   Jens Axboe <axboe@fb.com> | 2015-01-23 14:18:00 -0700 |
| commit | 24391c0dc57c3756a219defaa781e68637d6ab7d (patch) | |
| tree | 4d0e5b213c017e622d69d916c9e13e7f6e805368 /include/linux/blk-mq.h | |
| parent | block: support different tag allocation policy (diff) | |
| download | linux-dev-24391c0dc57c3756a219defaa781e68637d6ab7d.tar.xz linux-dev-24391c0dc57c3756a219defaa781e68637d6ab7d.zip | |
blk-mq: add tag allocation policy
This is the blk-mq part to support tag allocation policy. The default
allocation policy isn't changed (though it's not a strict FIFO). The new
policy is round-robin for libata. But it's a try-best implementation. If
multiple tasks are competing, the tags returned will be mixed (which is
unavoidable even with !mq, as requests from different tasks can be
mixed in queue)
Cc: Jens Axboe <axboe@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'include/linux/blk-mq.h')
| -rw-r--r-- | include/linux/blk-mq.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 5b6500c77ed2..86b08b1a5eba 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -147,6 +147,8 @@ enum { BLK_MQ_F_SG_MERGE = 1 << 2, BLK_MQ_F_SYSFS_UP = 1 << 3, BLK_MQ_F_DEFER_ISSUE = 1 << 4, + BLK_MQ_F_ALLOC_POLICY_START_BIT = 8, + BLK_MQ_F_ALLOC_POLICY_BITS = 1, BLK_MQ_S_STOPPED = 0, BLK_MQ_S_TAG_ACTIVE = 1, @@ -155,6 +157,12 @@ enum { BLK_MQ_CPU_WORK_BATCH = 8, }; +#define BLK_MQ_FLAG_TO_ALLOC_POLICY(flags) \ + ((flags >> BLK_MQ_F_ALLOC_POLICY_START_BIT) & \ + ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1)) +#define BLK_ALLOC_POLICY_TO_MQ_FLAG(policy) \ + ((policy & ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1)) \ + << BLK_MQ_F_ALLOC_POLICY_START_BIT) struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *); void blk_mq_finish_init(struct request_queue *q); |