From dac56212e8127dbc0bff7be35c508bc280213309 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 17 Apr 2015 16:23:59 -0600 Subject: [PATCH] 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 Signed-off-by: Jens Axboe --- Reading git-format-patch failed