diff options
| author | Andrew Morton <akpm@osdl.org> | 2006-06-25 05:47:49 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-06-25 10:01:07 -0700 |
| commit | b61367732fc273977cc3fb85c272ce1a7bb1f533 (patch) | |
| tree | 92aa6fc7f58b65f322f32612741c64347bc57152 /kernel | |
| parent | 232acbcf5304c29f5bb03b0dddeaefd0f98ef45e (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')
| -rw-r--r-- | kernel/workqueue.c | 28 |
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, return ret; } -int schedule_on_each_cpu(void (*func) (void *info), void *info) +/** + * schedule_on_each_cpu - call a function on each online CPU from keventd + * @func: the function to call + * @info: a pointer to pass to func() + * + * Returns zero on success. + * Returns -ve errno on failure. + * + * Appears to be racy against CPU hotplug. + * + * schedule_on_each_cpu() is very slow. + */ +int schedule_on_each_cpu(void (*func)(void *info), void *info) { int cpu; - struct work_struct *work; + struct work_struct *works; - work = kmalloc(NR_CPUS * sizeof(struct work_struct), GFP_KERNEL); - - if (!work) + works = alloc_percpu(struct work_struct); + if (!works) return -ENOMEM; + for_each_online_cpu(cpu) { - INIT_WORK(work + cpu, func, info); + INIT_WORK(per_cpu_ptr(works, cpu), func, info); __queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu), - work + cpu); + per_cpu_ptr(works, cpu)); } flush_workqueue(keventd_wq); - kfree(work); + free_percpu(works); return 0; } |