From: Jens Axboe Date: Wed, 21 May 2014 20:01:15 +0000 (-0600) Subject: blk-mq: save memory by freeing requests on unused hardware queues X-Git-Tag: omap-for-v3.16/fixes-against-rc1~39^2~49^2~29 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=484b4061e6683e0e6a09c7455f80781128dc8a6b;p=pandora-kernel.git blk-mq: save memory by freeing requests on unused hardware queues Depending on the topology of the machine and the number of queues exposed by a device, we can end up in a situation where some of the hardware queues are unused (as in, they don't map to any software queues). For this case, free up the memory used by the request map, as we will not use it. This can be a substantial amount of memory, depending on the number of queues vs CPUs and the queue depth of the device. Signed-off-by: Jens Axboe --- Reading git-diff-tree failed