Messages in this thread | | | Date | Mon, 27 Jun 2016 09:55:22 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH] locking/osq: Drop the overload of osq lock |
| |
On Sun, Jun 26, 2016 at 12:59:01PM +0800, panxinhui wrote: > > > 在 2016年6月26日,03:12,Peter Zijlstra <peterz@infradead.org> 写道: > > > > On Sun, Jun 26, 2016 at 01:27:51AM +0800, panxinhui wrote: > > > >> by the way I still think mutex_unlock has a big overload too. > > > > Do you mean overhead? > > > oh, maybe you are right.
> mutex_unlock ’s implementation uses inc_return variant on ppc, and > that’s expensive. I am thinking of using cmpxchg instead.
That statement doesn't make any sense. PPC is an LL/SC arch, inc_return and cmpxchg are the 'same' LL/SC loop.
| |