work_on_cpu: Use our own workqueue.

Impact: remove potential clashes with generic kevent workqueue

Annoyingly, some places we want to use work_on_cpu are already in
workqueues.  As per Ingo's suggestion, we create a different workqueue
for work_on_cpu.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index a35afdb..1f0c509 100644 (file)
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -971,6 +971,8 @@ undo:
 }
 
 #ifdef CONFIG_SMP
+static struct workqueue_struct *work_on_cpu_wq __read_mostly;
+
 struct work_for_cpu {
        struct work_struct work;
        long (*fn)(void *);
@@ -1001,7 +1003,7 @@ long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg)
        INIT_WORK(&wfc.work, do_work_for_cpu);
        wfc.fn = fn;
        wfc.arg = arg;
-       schedule_work_on(cpu, &wfc.work);
+       queue_work_on(cpu, work_on_cpu_wq, &wfc.work);
        flush_work(&wfc.work);
 
        return wfc.ret;
@@ -1019,4 +1021,8 @@ void __init init_workqueues(void)
        hotcpu_notifier(workqueue_cpu_callback, 0);
        keventd_wq = create_workqueue("events");
        BUG_ON(!keventd_wq);
+#ifdef CONFIG_SMP
+       work_on_cpu_wq = create_workqueue("work_on_cpu");
+       BUG_ON(!work_on_cpu_wq);
+#endif
 }