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

Linus Torvalds
2009-01-07T23:20:39Z

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.

Linus