From: Raghavendra K T Date: Thu, 19 Jul 2012 09:47:52 +0000 (+0530) Subject: KVM: Choose better candidate for directed yield X-Git-Tag: omap-for-v3.7-rc1/fixes-cpufreq-signed~15^2~101^2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=06e48c510aa37f6e791602e6420422ea7071fe94;p=pandora-kernel.git KVM: Choose better candidate for directed yield Currently, on a large vcpu guests, there is a high probability of yielding to the same vcpu who had recently done a pause-loop exit or cpu relax intercepted. Such a yield can lead to the vcpu spinning again and hence degrade the performance. The patchset keeps track of the pause loop exit/cpu relax interception and gives chance to a vcpu which: (a) Has not done pause loop exit or cpu relax intercepted at all (probably he is preempted lock-holder) (b) Was skipped in last iteration because it did pause loop exit or cpu relax intercepted, and probably has become eligible now (next eligible lock holder) Signed-off-by: Raghavendra K T Reviewed-by: Marcelo Tosatti Reviewed-by: Rik van Riel Tested-by: Christian Borntraeger # on s390x Signed-off-by: Avi Kivity --- Reading git-diff-tree failed