From: Jens Axboe Date: Thu, 22 Jan 2015 19:07:58 +0000 (-0700) Subject: NVMe: avoid kmalloc/kfree for smaller IO X-Git-Tag: omap-for-v4.1/prcm-dts-mfd-syscon-fix~101^2~5 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ac3dd5bd128b1d1ce2a037775766f39d06a4848a;p=pandora-kernel.git NVMe: avoid kmalloc/kfree for smaller IO Currently we allocate an nvme_iod for each IO, which holds the sg list, prps, and other IO related info. Set a threshold of 2 pages and/or 8KB of data, below which we can just embed this in the per-command pdu in blk-mq. For any IO at or below NVME_INT_PAGES and NVME_INT_BYTES, we save a kmalloc and kfree. For higher IOPS, this saves up to 1% of CPU time. Signed-off-by: Jens Axboe Reviewed-by: Keith Busch --- Reading git-diff-tree failed