Messages in this thread | | | Date | Mon, 15 Jun 2009 17:40:25 +0900 | From | Hidetoshi Seto <> | Subject | Re: [PATCH 02/16] x86, mce: call-in should be after updating global_nwo |
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huang ying wrote: > 2009/6/15 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>: >> At the beginning of Monarch synchronization, processors wait until >> all of them have entered the exception handler and then check the >> global_nwo to determine if any of them saw a fatal event. >> >> However since current code does call-in before updating global_nwo, >> it might happen that the global_nwo does not reflect some of local >> nwo at the time. This might break printing corrected errors not >> handled yet on panic. > > This is almost same as the patch that I just posted. I think this is > because it trigger a failure in mce-test suite, and we both find the > failure.
That's right.
> But your patch lacks memory barrier between mce_callin and global_nwo > updating/reading. Atomic operations does not imply memory barrier.
You are right. I agree that your patch is better fix.
It seems my patch includes cleanup for mce_start(), so I'll extract it and make another patch soon.
Thanks, H.Seto
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