[PATCH] tracing: Don't assume possible cpu list have contenious number

From: KOSAKI Motohiro
Date: Mon Mar 09 2009 - 21:50:14 EST



"for (++cpu ; cpu < num_possible_cpus(); cpu++)" statement assume
possible cpus have contenious number. but that's wrong assumption.

Insted, cpumask_next() should be used.


Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
---
kernel/trace/trace_workqueue.c | 14 +++++++-------
1 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/kernel/trace/trace_workqueue.c b/kernel/trace/trace_workqueue.c
index e6c4d00..46b12db 100644
--- a/kernel/trace/trace_workqueue.c
+++ b/kernel/trace/trace_workqueue.c
@@ -91,7 +91,7 @@ static void probe_workqueue_creation(struct task_struct *wq_thread, int cpu)
struct cpu_workqueue_stats *cws;
unsigned long flags;

- WARN_ON(cpu < 0 || cpu >= num_possible_cpus());
+ WARN_ON(cpu < 0);

/* Workqueues are sometimes created in atomic context */
cws = kzalloc(sizeof(struct cpu_workqueue_stats), GFP_ATOMIC);
@@ -175,12 +175,12 @@ static void *workqueue_stat_next(void *prev, int idx)
spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
if (list_is_last(&prev_cws->list, &workqueue_cpu_stat(cpu)->list)) {
spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
- for (++cpu ; cpu < num_possible_cpus(); cpu++) {
- ret = workqueue_stat_start_cpu(cpu);
- if (ret)
- return ret;
- }
- return NULL;
+ do {
+ cpu = cpumask_next(cpu, cpu_possible_mask);
+ if (cpu >= nr_cpu_ids)
+ return NULL;
+ } while (!(ret = workqueue_stat_start_cpu(cpu)));
+ return ret;
}
spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);

--
1.6.1.2



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