From: Mike Galbraith Date: Mon, 28 Jan 2013 11:19:25 +0000 (+0100) Subject: sched: Fix select_idle_sibling() bouncing cow syndrome X-Git-Tag: v3.9-rc1~172^2~9 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e0a79f529d5ba2507486d498b25da40911d95cf6;p=pandora-kernel.git sched: Fix select_idle_sibling() bouncing cow syndrome If the previous CPU is cache affine and idle, select it. The current implementation simply traverses the sd_llc domain, taking the first idle CPU encountered, which walks buddy pairs hand in hand over the package, inflicting excruciating pain. 1 tbench pair (worst case) in a 10 core + SMT package: pre 15.22 MB/sec 1 procs post 252.01 MB/sec 1 procs Signed-off-by: Mike Galbraith Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1359371965.5783.127.camel@marge.simpson.net Signed-off-by: Ingo Molnar --- Reading git-diff-tree failed