sched: Fix vmark regression on big machines

commit 50b926e439620c469565e8be0f28be78f5fca1ce upstream

SD_PREFER_SIBLING is set at the CPU domain level if power saving isn't
enabled, leading to many cache misses on large machines as we traverse
looking for an idle shared cache to wake to.  Change the enabler of
select_idle_sibling() to SD_SHARE_PKG_RESOURCES, and enable same at the
sibling domain level.

Reported-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1262612696.15495.15.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/include/linux/topology.h b/include/linux/topology.h
index 57e63579bfdd7f193511675fc9ed26141b586638..5b81156780b17f8bf52608ca7b8230dd638a530a 100644 (file)
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -99,7 +99,7 @@ int arch_update_cpu_topology(void);
                                | 1*SD_WAKE_AFFINE                      \
                                | 1*SD_SHARE_CPUPOWER                   \
                                | 0*SD_POWERSAVINGS_BALANCE             \
-                               | 0*SD_SHARE_PKG_RESOURCES              \
+                               | 1*SD_SHARE_PKG_RESOURCES              \
                                | 0*SD_SERIALIZE                        \
                                | 0*SD_PREFER_SIBLING                   \
                                ,                                       \

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index c0055519ee736f1cca33e11bd75bd12faece0ac1..f719dfabf78e5ecfa184b415c248c6021bdb7970 100644 (file)
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1490,7 +1490,7 @@ select_task_rq_fair(struct rq *rq, struct task_struct *p, int sd_flag, int wake_
                         * If there's an idle sibling in this domain, make that
                         * the wake_affine target instead of the current cpu.
                         */
-                       if (tmp->flags & SD_PREFER_SIBLING)
+                       if (tmp->flags & SD_SHARE_PKG_RESOURCES)
                                target = select_idle_sibling(p, tmp, target);
 
                        if (target >= 0) {