From 1863f62155b5d871bd97ca60f69b7a407d436b7a Mon Sep 17 00:00:00 2001 From: Alex Shi Date: Fri, 20 Jul 2012 14:19:50 +0800 Subject: [PATCH] sched/numa: Add SD_PERFER_SIBLING to CPU domain Commit a75d230806f ("sched: Remove stale power aware scheduling remnants and dysfunctional knobs") removed SD_PERFER_SIBLING from the CPU domain. On NUMA machines this causes that load_balance() doesn't perfer LCPU in same physical CPU package. It causes some actual performance regressions on our NUMA machines from Core2 to NHM and SNB. Adding this domain flag again recovers the performance drop. This change doesn't have any bad impact on any of my benchmarks: specjbb, kbuild, fio, hackbench .. etc, on all my machines. Signed-off-by: Alex Shi Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1342765190-21540-1-git-send-email-alex.shi@intel.com Signed-off-by: Ingo Molnar --- include/linux/topology.h | 1 + 1 file changed, 1 insertion(+) diff --git a/include/linux/topology.h b/include/linux/topology.h index e91cd43394dfa..fec12d667211d 100644 --- a/include/linux/topology.h +++ b/include/linux/topology.h @@ -164,6 +164,7 @@ int arch_update_cpu_topology(void); | 0*SD_SHARE_CPUPOWER \ | 0*SD_SHARE_PKG_RESOURCES \ | 0*SD_SERIALIZE \ + | 1*SD_PREFER_SIBLING \ , \ .last_balance = jiffies, \ .balance_interval = 1, \ -- 2.39.5