On Fri, Jun 09, 2017 at 01:36:08AM +1000, Nicholas Piggin wrote: > The hwsync in the context switch code to prevent MMIO access being > reordered from the point of view of a single process if it gets > migrated to a different CPU is not required because there is an hwsync > performed earlier in the context switch path. > > Comment this so it's clear enough if anything changes on the scheduler > or the powerpc sides. Remove the hwsync from _switch. > > This improves context switch performance by 2-3% on POWER8. > > Cc: Peter Zijlstra <pet...@infradead.org> > Signed-off-by: Nicholas Piggin <npig...@gmail.com>
Acked-by: Peter Zijlstra (Intel) <pet...@infradead.org>