Re: [PATCH -v5][RFC]: mutex: implement adaptive spinning

Steven Rostedt
2009-01-07T23:50:00Z

On Wed, 7 Jan 2009, Linus Torvalds wrote:
> On Wed, 7 Jan 2009, Dave Kleikamp wrote:
> >
> > Do you need to even do that if CONFIG_DEBUG_PAGEALLOC is unset?
>
> No.
>
> > Something like:
> >
> > #ifdef CONFIG_DEBUG_PAGEALLOC
> > /*
> > * Need to access the cpu field knowing that
> > * DEBUG_PAGEALLOC could have unmapped it if
> > * the mutex owner just released it and exited.
> > */
> > if (probe_kernel_address(&thread->cpu, cpu))
> > break;
> > #else
> > cpu = thread->cpu;
> > #endif
>
> yes. That would work fine.

What about memory hotplug as Ingo mentioned?

Should that be:

#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_MEMORY_HOTPLUG)

??

-- Steve