diff options
| author | Siddha, Suresh B <suresh.b.siddha@intel.com> | 2005-09-10 00:26:21 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-09-10 10:06:24 -0700 |
| commit | 0c117f1b4d14380baeed9c883f765ee023da8761 (patch) | |
| tree | 8bd81914e49493bdae4b04db307a48dcfc0b6316 /kernel/sched.c | |
| parent | fa3b6ddc3f4a8eadba52234134cdb59c28b5332d (diff) | |
[PATCH] sched: allow the load to grow upto its cpu_power
Don't pull tasks from a group if that would cause the group's total load to
drop below its total cpu_power (ie. cause the group to start going idle).
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/sched.c')
| -rw-r--r-- | kernel/sched.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 1dc29dec38a9..dbd4490afec1 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1910,6 +1910,7 @@ find_busiest_group(struct sched_domain *sd, int this_cpu, { struct sched_group *busiest = NULL, *this = NULL, *group = sd->groups; unsigned long max_load, avg_load, total_load, this_load, total_pwr; + unsigned long max_pull; int load_idx; max_load = this_load = total_load = total_pwr = 0; @@ -1959,7 +1960,7 @@ find_busiest_group(struct sched_domain *sd, int this_cpu, group = group->next; } while (group != sd->groups); - if (!busiest || this_load >= max_load) + if (!busiest || this_load >= max_load || max_load <= SCHED_LOAD_SCALE) goto out_balanced; avg_load = (SCHED_LOAD_SCALE * total_load) / total_pwr; @@ -1979,8 +1980,12 @@ find_busiest_group(struct sched_domain *sd, int this_cpu, * by pulling tasks to us. Be careful of negative numbers as they'll * appear as very large values with unsigned longs. */ + + /* Don't want to pull so many tasks that a group would go idle */ + max_pull = min(max_load - avg_load, max_load - SCHED_LOAD_SCALE); + /* How much load to actually move to equalise the imbalance */ - *imbalance = min((max_load - avg_load) * busiest->cpu_power, + *imbalance = min(max_pull * busiest->cpu_power, (avg_load - this_load) * this->cpu_power) / SCHED_LOAD_SCALE; |