From: Jens Axboe Date: Tue, 7 Oct 2014 14:39:20 +0000 (-0600) Subject: blk-mq: fix potential hang if rolling wakeup depth is too high X-Git-Tag: omap-for-v3.19/prcm-cleanup~50^2~8 X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=abab13b5c4fd1fec4f9a61622548012d93dc2831;p=pandora-kernel.git blk-mq: fix potential hang if rolling wakeup depth is too high We currently divide the queue depth by 4 as our batch wakeup count, but we split the wakeups over BT_WAIT_QUEUES number of wait queues. This defaults to 8. If the product of the resulting batch wake count and BT_WAIT_QUEUES is higher than the device queue depth, we can get into a situation where a task goes to sleep waiting for a request, but never gets woken up. Reported-by: Bart Van Assche Fixes: 4bb659b156996 Cc: stable@kernel.org Signed-off-by: Jens Axboe --- Reading git-diff-tree failed