summaryrefslogtreecommitdiff
path: root/arch
diff options
context:
space:
mode:
authorSiddha, Suresh B <suresh.b.siddha@intel.com>2006-06-27 02:54:42 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-27 17:32:45 -0700
commit5c45bf279d378d436ce45825c0f136696c7b6109 (patch)
tree80e2fcf4866b84fccb787562e1a83b16f4bc8850 /arch
parent369381694ddcf03f1de403501c8b97099b5109ec (diff)
[PATCH] sched: mc/smt power savings sched policy
sysfs entries 'sched_mc_power_savings' and 'sched_smt_power_savings' in /sys/devices/system/cpu/ control the MC/SMT power savings policy for the scheduler. Based on the values (1-enable, 0-disable) for these controls, sched groups cpu power will be determined for different domains. When power savings policy is enabled and under light load conditions, scheduler will minimize the physical packages/cpu cores carrying the load and thus conserving power(with a perf impact based on the workload characteristics... see OLS 2005 CMP kernel scheduler paper for more details..) Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Con Kolivas <kernel@kolivas.org> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/i386/kernel/smpboot.c8
-rw-r--r--arch/x86_64/kernel/smpboot.c8
2 files changed, 10 insertions, 6 deletions
diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c
index ab5275beddf7..89e7315e539c 100644
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -448,10 +448,12 @@ cpumask_t cpu_coregroup_map(int cpu)
struct cpuinfo_x86 *c = cpu_data + cpu;
/*
* For perf, we return last level cache shared map.
- * TBD: when power saving sched policy is added, we will return
- * cpu_core_map when power saving policy is enabled
+ * And for power savings, we return cpu_core_map
*/
- return c->llc_shared_map;
+ if (sched_mc_power_savings || sched_smt_power_savings)
+ return cpu_core_map[cpu];
+ else
+ return c->llc_shared_map;
}
/* representing cpus for which sibling maps can be computed */
diff --git a/arch/x86_64/kernel/smpboot.c b/arch/x86_64/kernel/smpboot.c
index 4e9755179ecf..540c0ccbcccc 100644
--- a/arch/x86_64/kernel/smpboot.c
+++ b/arch/x86_64/kernel/smpboot.c
@@ -455,10 +455,12 @@ cpumask_t cpu_coregroup_map(int cpu)
struct cpuinfo_x86 *c = cpu_data + cpu;
/*
* For perf, we return last level cache shared map.
- * TBD: when power saving sched policy is added, we will return
- * cpu_core_map when power saving policy is enabled
+ * And for power savings, we return cpu_core_map
*/
- return c->llc_shared_map;
+ if (sched_mc_power_savings || sched_smt_power_savings)
+ return cpu_core_map[cpu];
+ else
+ return c->llc_shared_map;
}
/* representing cpus for which sibling maps can be computed */