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author | Jens Axboe | 2015-04-17 16:23:59 -0600 |
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committer | Jens Axboe | 2015-05-05 13:32:49 -0600 |
commit | dac56212e8127dbc0bff7be35c508bc280213309 (patch) | |
tree | a1a066d7f6deb7d66403137b8edafb394ce0ca6a /drivers/dma/sirf-dma.c | |
parent | c4cf5261f8bffd9de132b50660a69148e7575bd6 (diff) |
bio: skip atomic inc/dec of ->bi_cnt for most use cases
Struct bio has a reference count that controls when it can be freed.
Most uses cases is allocating the bio, which then returns with a
single reference to it, doing IO, and then dropping that single
reference. We can remove this atomic_dec_and_test() in the completion
path, if nobody else is holding a reference to the bio.
If someone does call bio_get() on the bio, then we flag the bio as
now having valid count and that we must properly honor the reference
count when it's being put.
Tested-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers/dma/sirf-dma.c')
0 files changed, 0 insertions, 0 deletions