RE: [PATCH] fix x2apic defect that Linux kernel doesn't mask 8259Ainterrupt during the time window between changing VT-d table base addressand initializing these VT-d entries(smpboot.c and apic.c )

[Zhang, Lin-Bao (Linux Kernel R&D)]

> -----Original Message-----
> From: Suresh Siddha [mailto:suresh.b.siddha@xxxxxxxxx]
> Sent: 2012å10æ10æ 18:02
> > > So I looked at why you are seeing the problem with v2.6.32 but not
> > > with the recent kernels. And I think I found out the reason.
> >
> > I want to know what masking IO-APIC means?
> 
> As the platform is configured to use virtual-wire B and the corresponding
> IO-APIC RTE is masked, that interrupt will be dropped.
> 
thanks for your explanation and confirm, I also consulted BIOS guys , 
yes, interrupt will be dropped , software didn't see them,and don't go to handle them. 
So we OS don't need to disable 8259A interrupt during the window 
, only if 2.6.32 has applied your patch(triggered some actions to mask IO-apic)
That's good. Perfect design . thanks.

Here we go!
  
---------------
-- Bob(LinBao Zhang)
HP linux kernel enginner


N‹§²æìr¸›yúèšØb²X¬¶ÇvØ^–)Þ{.nÇ+‰·¥Š{±‘êçzX§¶›¡Ü}©ž²ÆzÚ&j:+v‰¨¾«‘êçzZ+€Ê+zf£¢·hšˆ§~†­†Ûiÿûàz¹®w¥¢¸?™¨è­Ú&¢)ßf”ù^jÇy§m…á@A«a¶Úÿ0¶ìh®å’i