Messages in this thread | | | From | Mark Gross <> | Subject | Re: [PATCH] multithreaded coredumps for elf exeecutables | Date | Thu, 21 Mar 2002 09:59:49 -0500 |
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On Thursday 21 March 2002 12:34 pm, Alan Cox wrote: > > This why I grabbed all those locks, and did the two sets of IPI's in the > > tcore patch. Once the runqueue lock is grabbed, even if that process on > > the > > If you IPI holding a lock whats going to happen if while the IPI is going > across the cpus the other processor tries to grab the runqueue lock and > is spinning on it with interrupts off ?
Then the at least 2 CPU's would quickly become dead locked on the synchronization IPI this patch sends at the end of the suspend_other_threads function call.
Interrupts shouldn't be turned off when grabbing the runqueue lock. Its also a bad thing if they would happen to be off while calling into to schedule.
I think schedule was designed to be called only while interrupts are turned on. It BUG's if "in_interrupt" to enforce this.
--mgross
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