Re: Linux 4.9.6 ( Restore IO-APIC irq_chip retrigger callback , breaks my box )

[Ruslan Ruslichenko -X (rruslich - GLOBALLOGIC INC at Cisco)]

On 02/06/2017 07:41 PM, Greg KH wrote:
> On Mon, Feb 06, 2017 at 06:30:15PM +0100, Gabriel C wrote:
> > On 26.01.2017 08:48, Greg KH wrote:
> >
> > Hi Greg,
> >
> > > I'm announcing the release of the 4.9.6 kernel.
> >
> > Somewhat late , however I didn't tested 4.9.6 but jumped from 4.9.5 to 4.9.7
> > and found out by box won't boot anymore.
> >
> > It hangs early and freeze with a lot RCU warnings.
> > Since I cannot setup a netconsole right now I cannot post the errors , really sorry.
> >
> > ( but I could make a picture if needed )
> >
> >
> > I bisected it down to :
> >
> > > Ruslan Ruslichenko (1):
> > >        x86/ioapic: Restore IO-APIC irq_chip retrigger callback
> > Reverting this one fixes the problem for me..
> >
> > Also this problem exists in Linus tree , I tested on:
> > 4.10.0-rc6-00167-ga0a28644c1cf
> Ok, at least we are consistent :)
>
> > The box is a PRIMERGY TX200 S5 , 2 socket , 2 x E5520 CPU(s) installed.
> >
> > Config:
> > https://raw.githubusercontent.com/frugalware/frugalware-current/master/source/base/kernel/config.x86_64
> Ruslan, any thoughts about what to do here?
This looks strange. What this patch does is just revert previous 
behavior, broken by d32932d02e18.
So we can try to test with last v4.1 stable, where retrigger callback 
were still present.

Also on v4.10 maybe check with software emulation of this feature and 
reverted patch, e.g.:

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index e487493..49c3c71 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -170,6 +170,7 @@ config X86
        select USER_STACKTRACE_SUPPORT
        select VIRT_TO_BUS
        select X86_FEATURE_NAMES                if PROC_FS
+       select HARDIRQS_SW_RESEND

 config INSTRUCTION_DECODER
        def_bool y

I think for further debugging logs will be needed.
> thanks,
>
> greg k-h