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| author | Jens Axboe <axboe@fb.com> | 2015-04-17 16:23:59 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2015-05-05 13:32:49 -0600 |
| commit | dac56212e8127dbc0bff7be35c508bc280213309 (patch) | |
| tree | a1a066d7f6deb7d66403137b8edafb394ce0ca6a /fs/xfs | |
| parent | c4cf5261f8bffd9de132b50660a69148e7575bd6 (diff) | |
| download | linux-dac56212e8127dbc0bff7be35c508bc280213309.tar.bz2 | |
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 'fs/xfs')
| -rw-r--r-- | fs/xfs/xfs_aops.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c index a56960dd1684..095f94c2d8b5 100644 --- a/fs/xfs/xfs_aops.c +++ b/fs/xfs/xfs_aops.c @@ -356,7 +356,6 @@ xfs_end_bio( { xfs_ioend_t *ioend = bio->bi_private; - ASSERT(atomic_read(&bio->bi_cnt) >= 1); ioend->io_error = test_bit(BIO_UPTODATE, &bio->bi_flags) ? 0 : error; /* Toss bio and pass work off to an xfsdatad thread */ |