On Fri, Apr 06, 2007 at 11:25:00PM -0700, Andrew Morton wrote:
> On Fri, 6 Apr 2007 14:41:50 -0700 "Keshavamurthy, Anil S" <[email protected]> wrote:
>
> > Subject: Avoid checking for cpu gone when CONFIG_HOTPLUG_CPU not defined
> >
> > Avoid checking for cpu gone in mm hot path when
> > CONFIG_HOTPLUG_CPU is not defined.
> >
> > Signed-off-by: Anil S Keshavamurthy <[email protected]>
> >
> > ---
> > arch/i386/kernel/smp.c | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > Index: work/arch/i386/kernel/smp.c
> > ===================================================================
> > --- work.orig/arch/i386/kernel/smp.c
> > +++ work/arch/i386/kernel/smp.c
> > @@ -365,10 +365,12 @@ static void flush_tlb_others(cpumask_t c
> > BUG_ON(cpu_isset(smp_processor_id(), cpumask));
> > BUG_ON(!mm);
> >
> > +#ifdef CONFIG_HOTPLUG_CPU
> > /* If a CPU which we ran on has gone down, OK. */
> > cpus_and(cpumask, cpumask, cpu_online_map);
> > - if (cpus_empty(cpumask))
> > + if (unlikely(cpus_empty(cpumask)))
> > return;
> > +#endif
> >
> > /*
> > * i'm not happy about this global shared spinlock in the
>
> Fair enough.
>
> The code you're touching in with the original CPU-hotplug-for-i386 patches.
>
> x86_64 doesn't do it. It handles tlb flushing differently anyway. But I
> suspect that x86_64 is just buggy, unless all callers of flush_tlb_others()
> have taken care to disable preemption prior to their calculation of the
> passed-in cpumask.
>
> Shudder. Gautham, this is code which we can cheerfully delete when we get
> the freezer stuff done. Fortunately, Anil's patch will make it nice and
> easy to find again.
Ok, I will make a note of this one.
If the IO-test results are good, I hope to post the patchset sometime
this week.
Thanks and Regards
gautham.
--
Gautham R Shenoy
Linux Technology Center
IBM India.
"Freedom comes with a price tag of responsibility, which is still a bargain,
because Freedom is priceless!"
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
