From: Pallipadi, Venkatesh Date: Wed, 10 Feb 2010 18:35:31 +0000 (-0800) Subject: ACPI: Be in TS_POLLING state during mwait based C-state entry X-Git-Tag: v2.6.33~6^2~1^3 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d306ebc28649b89877a22158fe0076f06cc46f60;p=pandora-kernel.git ACPI: Be in TS_POLLING state during mwait based C-state entry ACPI deep C-state entry had a long standing bug/missing feature, wherein we were sending resched IPIs when an idle CPU is in mwait based deep C-state. Only mwait based C1 was using the write to the monitored address to wake up mwait'ing CPU. This patch changes the code to retain TS_POLLING bit if we are entering an mwait based deep C-state. The patch has been verified to reduce the number of resched IPIs in general and also improves the performance/power on workloads with low system utilization (i.e., when mwait based deep C-states are being used). Fixes "netperf ~50% regression with 2.6.33-rc1, bisect to 1b9508f" http://marc.info/?l=linux-kernel&m=126441481427331&w=4 Reported-by: Lin Ming Tested-by: Alex Shi Signed-off-by: Venkatesh Pallipadi Signed-off-by: Len Brown --- Reading git-diff-tree failed