[PATCH] cpusets: Allocate heap only when required

From: Viresh Kumar
Date: Thu Jan 23 2014 - 06:16:06 EST


update_flag() routine uses heap only when spread_flag_changed is true. Otherwise
heap isn't used, but is allocated and freed unnecessarily.

Fix this by allocating heap only when required.

Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
---
Rebased over linux-next/master

kernel/cpuset.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 4410ac6..9ccdfb2 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1326,16 +1326,18 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
if (err < 0)
goto out;

- err = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL);
- if (err < 0)
- goto out;
-
balance_flag_changed = (is_sched_load_balance(cs) !=
is_sched_load_balance(trialcs));

spread_flag_changed = ((is_spread_slab(cs) != is_spread_slab(trialcs))
|| (is_spread_page(cs) != is_spread_page(trialcs)));

+ if (spread_flag_changed) {
+ err = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL);
+ if (err < 0)
+ goto out;
+ }
+
mutex_lock(&callback_mutex);
cs->flags = trialcs->flags;
mutex_unlock(&callback_mutex);
@@ -1343,9 +1345,10 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
if (!cpumask_empty(trialcs->cpus_allowed) && balance_flag_changed)
rebuild_sched_domains_locked();

- if (spread_flag_changed)
+ if (spread_flag_changed) {
update_tasks_flags(cs, &heap);
- heap_free(&heap);
+ heap_free(&heap);
+ }
out:
free_trial_cpuset(trialcs);
return err;
--
1.7.12.rc2.18.g61b472e

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/