From ac3dd5bd128b1d1ce2a037775766f39d06a4848a Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 22 Jan 2015 12:07:58 -0700 Subject: [PATCH] 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-format-patch failed