Re: [PATCH] x86/hotplug: Silence APIC only after all irq's are migrated

2020-08-20 Thread Raj, Ashok
On Thu, Aug 20, 2020 at 11:21:24AM -0700, Evan Green wrote: > > > > > > I'm slightly unclear about whether interrupts are disabled at the core > > > by this point or not. I followed native_cpu_disable() up to > > > __cpu_disable(), up to take_cpu_down(). This is passed into a call to > > >

Re: [PATCH] x86/hotplug: Silence APIC only after all irq's are migrated

2020-08-20 Thread Evan Green
On Mon, Aug 17, 2020 at 11:33 AM Raj, Ashok wrote: > > Hi Evan > > Some details below, > > On Mon, Aug 17, 2020 at 11:12:17AM -0700, Evan Green wrote: > > Hi Ashok, > > Thank you, Srikanth, and Sukumar for some very impressive debugging here. > > > > On Fri, Aug 14, 2020 at 2:38 PM Ashok Raj

Re: [PATCH] x86/hotplug: Silence APIC only after all irq's are migrated

2020-08-20 Thread Mathias Nyman
On 15.8.2020 0.38, Ashok Raj wrote: > When offlining CPU's, fixup_irqs() migrates all interrupts away from the > outgoing CPU to an online CPU. Its always possible the device sent an > interrupt to the previous CPU destination. Pending interrupt bit in IRR in > lapic identifies such interrupts.

Re: [PATCH] x86/hotplug: Silence APIC only after all irq's are migrated

2020-08-17 Thread Raj, Ashok
Hi Evan Some details below, On Mon, Aug 17, 2020 at 11:12:17AM -0700, Evan Green wrote: > Hi Ashok, > Thank you, Srikanth, and Sukumar for some very impressive debugging here. > > On Fri, Aug 14, 2020 at 2:38 PM Ashok Raj wrote: > > > > When offlining CPU's, fixup_irqs() migrates all

Re: [PATCH] x86/hotplug: Silence APIC only after all irq's are migrated

2020-08-17 Thread Evan Green
Hi Ashok, Thank you, Srikanth, and Sukumar for some very impressive debugging here. On Fri, Aug 14, 2020 at 2:38 PM Ashok Raj wrote: > > When offlining CPU's, fixup_irqs() migrates all interrupts away from the > outgoing CPU to an online CPU. Its always possible the device sent an > interrupt to

Re: [PATCH] x86/hotplug: Silence APIC only after all irq's are migrated

2020-08-15 Thread Raj, Ashok
Hi Randy, On Fri, Aug 14, 2020 at 04:25:32PM -0700, Randy Dunlap wrote: > On 8/14/20 2:38 PM, Ashok Raj wrote: > > When offlining CPU's, fixup_irqs() migrates all interrupts away from the > > CPUs, Thanks for catching these. I'll fix all these suggested changes in my next rev

Re: [PATCH] x86/hotplug: Silence APIC only after all irq's are migrated

2020-08-15 Thread Raj, Ashok
Hi Randy For some unknown reason my previous response said its taiting to be delivered. On Fri, Aug 14, 2020 at 04:25:32PM -0700, Randy Dunlap wrote: > On 8/14/20 2:38 PM, Ashok Raj wrote: > > When offlining CPU's, fixup_irqs() migrates all interrupts away from the > > CPUs,

Re: [PATCH] x86/hotplug: Silence APIC only after all irq's are migrated

2020-08-14 Thread Randy Dunlap
On 8/14/20 2:38 PM, Ashok Raj wrote: > When offlining CPU's, fixup_irqs() migrates all interrupts away from the CPUs, > outgoing CPU to an online CPU. Its always possible the device sent an It's > interrupt to the previous CPU destination.

[PATCH] x86/hotplug: Silence APIC only after all irq's are migrated

2020-08-14 Thread Ashok Raj
When offlining CPU's, fixup_irqs() migrates all interrupts away from the outgoing CPU to an online CPU. Its always possible the device sent an interrupt to the previous CPU destination. Pending interrupt bit in IRR in lapic identifies such interrupts. apic_soft_disable() will not capture any new