diff options
| author | Mike Travis <travis@sgi.com> | 2009-01-10 21:58:11 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-01-11 19:13:22 +0100 |
| commit | d38b223c86db3162dc85b5a1997ac8a210e1660b (patch) | |
| tree | 3e232926a5fce47e910e4356e833be43b7b03592 /kernel/sched_rt.c | |
| parent | c90e785be2fd9dfaef1f030d0314e44052553736 (diff) | |
| download | lwn-d38b223c86db3162dc85b5a1997ac8a210e1660b.tar.gz lwn-d38b223c86db3162dc85b5a1997ac8a210e1660b.zip | |
cpumask: reduce stack usage in find_lowest_rq
Impact: reduce stack usage, cleanup
Use a cpumask_var_t in find_lowest_rq() and clean up other old
cpumask_t calls.
Signed-off-by: Mike Travis <travis@sgi.com>
Diffstat (limited to 'kernel/sched_rt.c')
| -rw-r--r-- | kernel/sched_rt.c | 36 |
1 files changed, 22 insertions, 14 deletions
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 954e1a81b796..da932f4c8524 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -960,16 +960,17 @@ static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu) static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask); -static inline int pick_optimal_cpu(int this_cpu, cpumask_t *mask) +static inline int pick_optimal_cpu(int this_cpu, + const struct cpumask *mask) { int first; /* "this_cpu" is cheaper to preempt than a remote processor */ - if ((this_cpu != -1) && cpu_isset(this_cpu, *mask)) + if ((this_cpu != -1) && cpumask_test_cpu(this_cpu, mask)) return this_cpu; - first = first_cpu(*mask); - if (first != NR_CPUS) + first = cpumask_first(mask); + if (first < nr_cpu_ids) return first; return -1; @@ -981,6 +982,7 @@ static int find_lowest_rq(struct task_struct *task) struct cpumask *lowest_mask = __get_cpu_var(local_cpu_mask); int this_cpu = smp_processor_id(); int cpu = task_cpu(task); + cpumask_var_t domain_mask; if (task->rt.nr_cpus_allowed == 1) return -1; /* No other targets possible */ @@ -1013,19 +1015,25 @@ static int find_lowest_rq(struct task_struct *task) if (this_cpu == cpu) this_cpu = -1; /* Skip this_cpu opt if the same */ - for_each_domain(cpu, sd) { - if (sd->flags & SD_WAKE_AFFINE) { - cpumask_t domain_mask; - int best_cpu; + if (alloc_cpumask_var(&domain_mask, GFP_ATOMIC)) { + for_each_domain(cpu, sd) { + if (sd->flags & SD_WAKE_AFFINE) { + int best_cpu; - cpumask_and(&domain_mask, sched_domain_span(sd), - lowest_mask); + cpumask_and(domain_mask, + sched_domain_span(sd), + lowest_mask); - best_cpu = pick_optimal_cpu(this_cpu, - &domain_mask); - if (best_cpu != -1) - return best_cpu; + best_cpu = pick_optimal_cpu(this_cpu, + domain_mask); + + if (best_cpu != -1) { + free_cpumask_var(domain_mask); + return best_cpu; + } + } } + free_cpumask_var(domain_mask); } /* |