From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>
Subject: Re: [PATCH] x86/IO-APIC: refine EOI-ing of migrating level interrupts
Date: Fri, 18 Nov 2011 18:01:39 +0000 [thread overview]
Message-ID: <4EC69D83.6010704@citrix.com> (raw)
In-Reply-To: <4EC625F90200007800061BFE@nat28.tlf.novell.com>
On 18/11/11 08:31, Jan Beulich wrote:
> Now that this is in, could you try (again on the offending system)
> whether adding e.g. a WARN_ON(vector != desc->arch.old_vector)
> prior to the just added call to eoi_IO_APIC_irq() (but inside the
> surrounding if()) would ever trigger (obviously you'd want to make
> sure that the code path actually gets executed at all - perhaps
> counting and printing the count once in a while would be the easiest
> thing to do)?
>
> If it does, we obviously need to stay with passing in vector. If not,
> we'd need to do another round of code inspection to determine
> whether indeed there's no race when relying on just the stored
> data.
>
> Thanks, Jan
So long as you also check for arch.old_vector != IRQ_UNASSIGNED_VECTOR,
this appears to be fine.
I will sort out a patch to change this behavior
--
Andrew Cooper - Dom0 Kernel Engineer, Citrix XenServer
T: +44 (0)1223 225 900, http://www.citrix.com
next prev parent reply other threads:[~2011-11-18 18:01 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-15 13:14 [PATCH] x86/IO-APIC: refine EOI-ing of migrating level interrupts Jan Beulich
2011-11-15 13:19 ` Andrew Cooper
2011-11-15 13:27 ` Jan Beulich
2011-11-15 13:35 ` Andrew Cooper
2011-11-15 13:43 ` Jan Beulich
2011-11-17 16:12 ` Andrew Cooper
2011-11-18 8:31 ` Jan Beulich
2011-11-18 18:01 ` Andrew Cooper [this message]
2011-11-18 18:57 ` Andrew Cooper
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