Messages in this thread | | | From | "Tian, Kevin" <> | Date | Sat, 7 May 2011 05:43:12 +0800 | Subject | RE: [PATCH v2 2/2] x86: don't unmask disabled irqs when migrating them |
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> From: Stefano Stabellini [mailto:stefano.stabellini@eu.citrix.com] > Sent: Friday, May 06, 2011 10:29 PM > > On Fri, 6 May 2011, Tian, Kevin wrote: > > > From: Thomas Gleixner > > > Sent: Friday, May 06, 2011 6:00 PM > > > > > > On Fri, 6 May 2011, Tian, Kevin wrote: > > > > x86: don't unmask disabled irqs when migrating them > > > > > > > > it doesn't make sense to mask/unmask a disabled irq when migrating > > > > it from offlined cpu to another, because it's not expected to > > > > handle any instance of it. Current mask/set_affinity/unmask steps > > > > may trigger unexpected instance on disabled irq which then simply > > > > bug on when there is no handler for it. One failing example is observed in > Xen. > > > > Xen pvops > > > > > > So there is no handler, why the heck is there an irq action? > > > > > > if (!irq_has_action(irq) .... > > > continue; > > > > > > Should have caught an uninitialized interrupt. If Xen abuses > > > interrupts that way, then it rightfully explodes. And we do not fix it by magic > somewhere else. > > > > sorry that my bad description here. there does be a dummy handler > > registered on such irqs which simply throws out a BUG_ON when hit. I > > should just say such injection is not expected instead of no handler. > > :-) > > I don't think this patch is necessary anymore after the event channel handling > cleanup patches I have just sent to the list. > Could you please try the following two patches: > > http://marc.info/?l=linux-kernel&m=130468120032172&w=2 > http://marc.info/?l=linux-kernel&m=130468178200468&w=2 > > and let me know if you still need this patch?
thanks, and I'll take a look at them.
Thanks Kevin
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