Messages in this thread |  | | Date | Fri, 30 Aug 2002 01:12:38 -0700 | From | Andrew Morton <> | Subject | Re: [patch] scheduler fixes, 2.5.32-BK |
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Ingo Molnar wrote: > > > - changes the migration code to use struct completion. Andrew pointed out > > that there might be a small window in where the up() touches the > > semaphore while the waiting task goes on and frees its stack. And > > completion is more suited for this kind of stuff anyway. > > actually, i think the race does not exist. up() is perfectly safely done > on the on-stack semaphore, because both the wake_up() done by __up() and > the __down() path takes the waitqueue spinlock, so i cannot see where the > up() touches the semaphore after the down()-ed task has been woken up. >
yep, looks like the killing of the semaphore_lock made the race go away.
But ia64, sparc and x86_64 use semaphore_lock, so they still are exposed. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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