Messages in this thread | | | Date | Thu, 28 Jun 2007 15:52:21 -0400 | From | Chuck Ebbert <> | Subject | Re: [PATCH] MTRR: Fix race causing set_mtrr to go into infinite loop |
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On 06/25/2007 06:34 PM, Andi Kleen wrote: > On Tuesday 26 June 2007 00:05:17 Chuck Ebbert wrote: >> On 06/25/2007 05:38 PM, Loic Prylli wrote: >> >> [cc: Andi] >> >>> Processors synchronization in set_mtrr requires the .gate field >>> to be set after .count field is properly initialized. Without an explicit >>> barrier, the compiler was reordering those memory stores. That was sometimes >>> causing a processor (in ipi_handler) to see the .gate change and >>> decrement .count before the latter is set by set_mtrr() (which >>> then hangs in a infinite loop with irqs disabled). > > Hmm, perhaps we should just put the smp_wmb into atomic_set(). > Near all other atomic operations have memory barriers too. I think > that would be the better fix.
Can we get something merged before 2.6.22-final?
The original patch seems okay... - 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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