Re: [MM] Make mm counters per cpu instead of atomic

Zhang, Yanmin
2009-11-19T00:45:38Z

On Tue, 2009-11-17 at 12:25 -0500, Christoph Lameter wrote:
> On Tue, 17 Nov 2009, Zhang, Yanmin wrote:
>
> > The right change above should be:
> > struct mm_counter *m = per_cpu_ptr(mm->rss, cpu);
>
> Right.
>
> > With the change, command 'make oldconfig' and a boot command still
> > hangs.
>
> Not sure if its worth spending more time on this but if you want I will
> consolidate the fixes so far and put out another patchset.
>
> Where does it hang during boot?
>
1) A init boot script calss pidof and pidof hands in
access_process_vm => (mutex_lock <=> mutex_unlock), so actually in
mm_reader_lock.
2) 'make oldconfig' hangs in sys_map => msleep, actually in mm_writer_lock.

I will check it today.