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authorChristoph Lameter <clameter@engr.sgi.com>2006-01-08 10:00:43 +0100
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-09 05:12:40 +0100
commit15316ba81aee6775d6079fb46c66c801989e7d10 (patch)
treec6190bdcc6e15fd8b5657a5932313e296b475577 /kernel
parent[PATCH] mm: free_pages opt (diff)
downloadlinux-15316ba81aee6775d6079fb46c66c801989e7d10.tar.xz
linux-15316ba81aee6775d6079fb46c66c801989e7d10.zip
[PATCH] add schedule_on_each_cpu()
swap migration's isolate_lru_page() currently uses an IPI to notify other processors that the lru caches need to be drained if the page cannot be found on the LRU. The IPI interrupt may interrupt a processor that is just processing lru requests and cause a race condition. This patch introduces a new function run_on_each_cpu() that uses the keventd() to run the LRU draining on each processor. Processors disable preemption when dealing the LRU caches (these are per processor) and thus executing LRU draining from another process is safe. Thanks to Lee Schermerhorn <lee.schermerhorn@hp.com> for finding this race condition. Signed-off-by: Christoph Lameter <clameter@sgi.com> 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.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 2bd5aee1c736..62d47220696a 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -419,6 +419,25 @@ int schedule_delayed_work_on(int cpu,
return ret;
}
+int schedule_on_each_cpu(void (*func) (void *info), void *info)
+{
+ int cpu;
+ struct work_struct *work;
+
+ work = kmalloc(NR_CPUS * sizeof(struct work_struct), GFP_KERNEL);
+
+ if (!work)
+ return -ENOMEM;
+ for_each_online_cpu(cpu) {
+ INIT_WORK(work + cpu, func, info);
+ __queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu),
+ work + cpu);
+ }
+ flush_workqueue(keventd_wq);
+ kfree(work);
+ return 0;
+}
+
void flush_scheduled_work(void)
{
flush_workqueue(keventd_wq);