svn commit: r234074 - in head/sys: amd64/amd64 i386/i386
attilio at freebsd.org
Tue Apr 10 12:55:33 UTC 2012
Il 10 aprile 2012 12:41, Marius Strobl <marius at alchemy.franken.de> ha scritto:
> On Tue, Apr 10, 2012 at 01:03:56AM +0100, Attilio Rao wrote:
>> Il 10 aprile 2012 00:09, Marius Strobl <marius at alchemy.franken.de> ha scritto:
>> > On Mon, Apr 09, 2012 at 10:41:19PM +0000, Attilio Rao wrote:
>> >> Author: attilio
>> >> Date: Mon Apr ??9 22:41:19 2012
>> >> New Revision: 234074
>> >> URL: http://svn.freebsd.org/changeset/base/234074
>> >> Log:
>> >> ?? BSP is not added to the mask of valid target CPUs for interrupts
>> >> ?? in set_apic_interrupt_ids(). Besides, set_apic_interrupts_ids() is not
>> >> ?? called in the !SMP case too.
>> >> ?? Fix this by:
>> >> ?? - Adding the BSP as an interrupt target directly in cpu_startup().
>> >> ?? - Remove an obsolete optimization where the BSP are skipped in
>> >> ?? ?? set_apic_interrupt_ids().
>> >> ?? Reported by: ?? ?? ?? ??jh
>> >> ?? Reviewed by: ?? ?? ?? ??jhb
>> >> ?? MFC after: ??3 days
>> >> ?? X-MFC: ?? ?? ?? ?? ?? ?? ??r233961
>> >> ?? Pointy hat to: ?? ?? ??me
>> >> Modified:
>> >> ?? head/sys/amd64/amd64/machdep.c
>> >> ?? head/sys/amd64/amd64/mp_machdep.c
>> >> ?? head/sys/i386/i386/machdep.c
>> >> ?? head/sys/i386/i386/mp_machdep.c
>> >> Modified: head/sys/amd64/amd64/machdep.c
>> >> ==============================================================================
>> >> --- head/sys/amd64/amd64/machdep.c ?? ??Mon Apr ??9 22:01:43 2012 ?? ?? ?? ??(r234073)
>> >> +++ head/sys/amd64/amd64/machdep.c ?? ??Mon Apr ??9 22:41:19 2012 ?? ?? ?? ??(r234074)
>> >> @@ -295,6 +295,11 @@ cpu_startup(dummy)
>> >> ?? ?? ?? vm_pager_bufferinit();
>> >> ?? ?? ?? cpu_setregs();
>> >> +
>> >> + ?? ?? /*
>> >> + ?? ?? ??* Add BSP as an interrupt target.
>> >> + ?? ?? ??*/
>> >> + ?? ?? intr_add_cpu(0);
>> >> ??}
>> > If I'm not mistaken, intr_add_cpu() is under #ifdef SMP, so it should be
>> > here as well.
>> You are right, sorry, I did forgot to test without SMP.
>> I think we still need intr_add_cpu() on cpu_startup() because of the
>> case smp_disabled = 1.
>> I think the attached patch should make its dirty job, opinion?
> I currently fail to see why the latter approach would be necessary,
> i.e. IMO wrapping the intr_add_cpu() calls in cpu_startup() should
> be sufficient. In case the kernel is compiled without SMP support,
> interrupt balancing support isn't available in the first place and
> the BSP is always the only available target (see the UP version of
> intr_next_cpu() at the end of x86/x86/intr_machdep.c), so there's
> no need to add the BSP as a valid target. If an SMP kernel is run
> on a UP machine or with SMP disabled, interrupt balancing support
> is available but the intr_add_cpu() calls in cpu_startup() will add
> the BSP as (the only) target, so everything should be fine. Maybe
> you can elaborate on why you think an SMP kernel with SMP disabled
> needs special handling.
I do not understand what you mean.
Right now there is a compile time issue where for !SMP kernel it won't
compile and this is what I'm trying to fix now, so I don't understand
what do you mean here.
Peace can only be achieved by understanding - A. Einstein
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