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. - 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/
