From: Ed Cashin Date: Fri, 5 Oct 2012 00:16:20 +0000 (-0700) Subject: aoe: for performance support larger packet payloads X-Git-Tag: omap-for-v3.7-rc1/fixes-cpufreq-signed~12^2~24 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3d5b06051cd5fa82c9a4285f7ce8650a0f0845ff;p=pandora-kernel.git aoe: for performance support larger packet payloads tAdd adds the ability to work with large packets composed of a number of segments, using the scatter gather feature of the block layer (biovecs) and the network layer (skb frag array). The motivation is the performance gained by using a packet data payload greater than a page size and by using the network card's scatter gather feature. Users of the out-of-tree aoe driver already had these changes, but since early 2011, they have complained of increased memory utilization and higher CPU utilization during heavy writes.[1] The commit below appears related, as it disables scatter gather on non-IP protocols inside the harmonize_features function, even when the NIC supports sg. commit f01a5236bd4b140198fbcc550f085e8361fd73fa Author: Jesse Gross Date: Sun Jan 9 06:23:31 2011 +0000 net offloading: Generalize netif_get_vlan_features(). With that regression in place, transmits always linearize sg AoE packets, but in-kernel users did not have this patch. Before 2.6.38, though, these changes were working to allow sg to increase performance. 1. http://www.spinics.net/lists/linux-mm/msg15184.html Signed-off-by: Ed Cashin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed