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authorAndrew Morton <akpm@osdl.org>2006-06-25 08:47:49 -0400
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-25 13:01:07 -0400
commitb61367732fc273977cc3fb85c272ce1a7bb1f533 (patch)
tree92aa6fc7f58b65f322f32612741c64347bc57152 /kernel/workqueue.c
parent232acbcf5304c29f5bb03b0dddeaefd0f98ef45e (diff)
[PATCH] schedule_on_each_cpu(): reduce kmalloc() size
schedule_on_each_cpu() presently does a large kmalloc - 96 kbytes on 1024 CPU 64-bit. Rework it so that we do one 8192-byte allocation and then a pile of tiny ones, via alloc_percpu(). This has a much higher chance of success (100% in the current VM). This also has the effect of reducing the memory requirements from NR_CPUS*n to num_possible_cpus()*n. Cc: Christoph Lameter <clameter@engr.sgi.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/workqueue.c')
-rw-r--r--kernel/workqueue.c28
1 files changed, 20 insertions, 8 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 740c5abceb07..f869aff6bc0c 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -428,22 +428,34 @@ int schedule_delayed_work_on(int cpu,
428 return ret; 428 return ret;
429} 429}
430 430
431int schedule_on_each_cpu(void (*func) (void *info), void *info) 431/**
432 * schedule_on_each_cpu - call a function on each online CPU from keventd
433 * @func: the function to call
434 * @info: a pointer to pass to func()
435 *
436 * Returns zero on success.
437 * Returns -ve errno on failure.
438 *
439 * Appears to be racy against CPU hotplug.
440 *
441 * schedule_on_each_cpu() is very slow.
442 */
443int schedule_on_each_cpu(void (*func)(void *info), void *info)
432{ 444{
433 int cpu; 445 int cpu;
434 struct work_struct *work; 446 struct work_struct *works;
435 447
436 work = kmalloc(NR_CPUS * sizeof(struct work_struct), GFP_KERNEL); 448 works = alloc_percpu(struct work_struct);
437 449 if (!works)
438 if (!work)
439 return -ENOMEM; 450 return -ENOMEM;
451
440 for_each_online_cpu(cpu) { 452 for_each_online_cpu(cpu) {
441 INIT_WORK(work + cpu, func, info); 453 INIT_WORK(per_cpu_ptr(works, cpu), func, info);
442 __queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu), 454 __queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu),
443 work + cpu); 455 per_cpu_ptr(works, cpu));
444 } 456 }
445 flush_workqueue(keventd_wq); 457 flush_workqueue(keventd_wq);
446 kfree(work); 458 free_percpu(works);
447 return 0; 459 return 0;
448} 460}
449 461