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sched: convert rebalance_domains() to cpumask_var_t.

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Impact: stack usage reduction

Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves
space in the stack.  cpumask_var_t is just a struct cpumask for
!CONFIG_CPUMASK_OFFSTACK.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Rusty Russell 2008-11-25 02:35:11 +10:30 committed by Ingo Molnar
parent 4d2732c63e
commit a0e902452d
1 changed files with 8 additions and 2 deletions
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10
kernel/sched.c
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@ -3850,7 +3850,11 @@ static void rebalance_domains(int cpu, enum cpu_idle_type idle)
unsigned long next_balance = jiffies + 60*HZ; unsigned long next_balance = jiffies + 60*HZ;
int update_next_balance = 0; int update_next_balance = 0;
int need_serialize; int need_serialize;
cpumask_t tmp; cpumask_var_t tmp;
/* Fails alloc? Rebalancing probably not a priority right now. */
if (!alloc_cpumask_var(&tmp, GFP_ATOMIC))
return;
for_each_domain(cpu, sd) { for_each_domain(cpu, sd) {
if (!(sd->flags & SD_LOAD_BALANCE)) if (!(sd->flags & SD_LOAD_BALANCE))
@ -3875,7 +3879,7 @@ static void rebalance_domains(int cpu, enum cpu_idle_type idle)
} }
if (time_after_eq(jiffies, sd->last_balance + interval)) { if (time_after_eq(jiffies, sd->last_balance + interval)) {
if (load_balance(cpu, rq, sd, idle, &balance, &tmp)) { if (load_balance(cpu, rq, sd, idle, &balance, tmp)) {
/* /*
* We've pulled tasks over so either we're no * We've pulled tasks over so either we're no
* longer idle, or one of our SMT siblings is * longer idle, or one of our SMT siblings is
@ -3909,6 +3913,8 @@ out:
*/ */
if (likely(update_next_balance)) if (likely(update_next_balance))
rq->next_balance = next_balance; rq->next_balance = next_balance;
free_cpumask_var(tmp);
} }
/* /*