Messages in this thread | | | Date | Fri, 12 Nov 2010 10:42:31 -0500 | From | Don Zickus <> | Subject | Re: [V2 PATCH 0/6] x86, NMI: give NMI handler a face-lift |
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On Fri, Nov 12, 2010 at 09:05:03AM -0600, Jason Wessel wrote: > On 11/12/2010 08:43 AM, Don Zickus wrote: > > Restructuring the nmi handler to be more readable and simpler. > > > > This is just laying the ground work for future improvements in this area. > > > > I also left out one of Huang's patch until we figure out how we are going > > to proceed with a new notifier. > > > > Tested 32-bit and 64-bit on AMD and Intel machines. > > > > V2: add a patch to kill DIE_NMI_IPI and add in priorities > > > > > > Had you tested this code with kgdb boot tests at all? > > CONFIG_LOCKUP_DETECTOR=y > CONFIG_HARDLOCKUP_DETECTOR=y > CONFIG_KGDB=y > CONFIG_KGDB_TESTS_ON_BOOT=y > CONFIG_KGDB_TESTS_BOOT_STRING="V1F100" > > There has been a regression in kgdb due to the use of perf/NMI in the > lockup detector ever since the new version has been introduced. The > perf callbacks in the lockup detector were consuming NMI events not > related to the call back and causing the kernel debugger not to work at > all on SMP systems configured with the lockup detector.
Well 2.6.36 should have fixed that. Perf was blindly eating all NMI events if it had a user. With the new lockup detector, that created a 'user' for perf and it happily ate everything. But we spent a lot of time trying to fix that for 2.6.36. If we missed something, we would like to know.
To answer your question, I doubt this patch series will change that outcome if it is still broken.
> > I was curious to know if this patch series fixed the problem as well as > to know if you could run the regression test when you make changes > related to the lockup / NMI path as it affects the kernel debug API.
Absolutely. I look forward to running tests with consumers of NMI other than perf. :-)
Thanks for the tip.
Cheers, Don
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