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| author | Jens Axboe | 2014-05-19 17:23:55 +0200 |
|---|---|---|
| committer | Jens Axboe | 2014-05-19 19:02:47 +0200 |
| commit | 1429d7c9467e1e3de0b0ff91d7e4d67c1a92f8a3 (patch) | |
| tree | 3b15abb587392becc4ba37d0869d25a4d9420d1d /block/blk-mq-tag.c | |
| parent | blk-mq: move the cache friendly bitmap type of out blk-mq-tag (diff) | |
| download | kernel-qcow2-linux-1429d7c9467e1e3de0b0ff91d7e4d67c1a92f8a3.tar.gz kernel-qcow2-linux-1429d7c9467e1e3de0b0ff91d7e4d67c1a92f8a3.tar.xz kernel-qcow2-linux-1429d7c9467e1e3de0b0ff91d7e4d67c1a92f8a3.zip | |
blk-mq: switch ctx pending map to the sparser blk_align_bitmap
Each hardware queue has a bitmap of software queues with pending
requests. When new IO is queued on a software queue, the bit is
set, and when IO is pruned on a hardware queue run, the bit is
cleared. This causes a lot of traffic. Switch this from the regular
BITS_PER_LONG bitmap to a sparser layout, similarly to what was
done for blk-mq tagging.
20% performance increase was observed for single threaded IO, and
about 15% performanc increase on multiple threads driving the
same device.
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/blk-mq-tag.c')
0 files changed, 0 insertions, 0 deletions