Attachment 156844 Details for Bug 242868 – tasklet2.patch

tasklet2.patch

tasklet2.patch (text/plain), 1.17 KB, created by IBM Bug Proxy on 2007-06-13 03:45:21 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: IBM Bug Proxy

Created: 2007-06-13 03:45:21 UTC

Size: 1.17 KB

patch

obsolete

>Index: 2.6-rt/kernel/softirq.c
>===================================================================
>--- 2.6-rt.orig/kernel/softirq.c	2007-06-12 20:30:11.000000000 -0700
>+++ 2.6-rt/kernel/softirq.c	2007-06-12 20:37:22.000000000 -0700
>@@ -544,6 +544,7 @@
> __tasklet_common_schedule(struct tasklet_struct *t, struct tasklet_head *head, unsigned int nr)
> {
> 	if (tasklet_trylock(t)) {
>+again:
> 		/* We may have been preempted before tasklet_trylock
> 		 * and __tasklet_action may have already run.
> 		 * So double check the sched bit while the takslet
>@@ -554,8 +555,21 @@
> 			t->next = head->list;
> 			head->list = t;
> 			raise_softirq_irqoff(nr);
>+			tasklet_unlock(t);
>+		} else {
>+			/* This is subtle. If we hit the corner case above
>+			 * It is possible that we get preempted right here,
>+			 * and another task has successfully called
>+			 * tasklet_schedule(), then this function, and
>+			 * failed on the trylock. Thus we must be sure
>+			 * before releasing the tasklet lock, that the
>+			 * SCHED_BIT is clear. Otherwise the tasklet
>+			 * may get its SCHED_BIT set, but not added to the
>+			 * list
>+			 */
>+			if (!tasklet_tryunlock(t))
>+				goto again;
> 		}
>-		tasklet_unlock(t);
> 	}
> }
>

Actions: View

Attachments on bug 242868: 156317 | 156318 | 156319 | 156835 | 156844 | 156940 | 156942