[lkml]   [2007]   [Mar]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] x86_64: avoid sending LOCAL_TIMER_VECTOR IPI to itself
Ingo Molnar wrote:
> * Ray Lee <> wrote:
>> Subject: [PATCH] x86_64: avoid sending LOCAL_TIMER_VECTOR IPI to
>> itself
>> Ray Lee reported, that on an UP kernel with "noapic" command line
>> option set, the box locks hard during boot.
> i think this bug deserves a bit more attention, because similar problems
> could be in other codepaths too.
> the problem here is that we tried to send an IPI to ourselves - which
> confused Ray's system which has an IO-APIC, but where due to noapic we
> keep the IO-APIC in its BIOS default.
> this isnt a new problem: the new time code just exposed it more
> prominently that it was visible before. (the SMP kernel probably would
> hang in a similar way on Ray's system)

Taking the hint, yes it does. (I'd never had a reason to test it before.)
Booting an SMP kernel without NOAPIC works, with NOAPIC hangs fairly early
on, implying a real fix to my problem belongs down at the arch level, I

> i dont see any clear debugging in the IPI code that excludes self-IPIs.
> I think the only valid way to do that is to use DEST_SELF. Andi?

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2007-03-25 21:27    [W:0.148 / U:0.840 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site