Messages in this thread | | | Date | Thu, 19 Jun 2014 11:09:16 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [bisected] pre-3.16 regression on open() scalability |
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On Thu, Jun 19, 2014 at 09:42:18AM -0500, Christoph Lameter wrote: > On Wed, 18 Jun 2014, Andi Kleen wrote: > > > I still think it's totally the wrong direction to pollute so > > many fast paths with this obscure debugging check workaround > > unconditionally. > > > > cond_resched() is in EVERY sleeping lock and in EVERY memory allocation! > > And these are really critical paths for many workloads. > > > > If you really wanted to do this I think you would first need > > to define a cond_resched_i_am_not_fast() or somesuch. > > > > Or put it all behind some debugging ifdef. > > Again I am fully on Andi's side here. Please remove these frequent calls > to cond_resched. If one wants a fully preemptable kernel then please use > CONFIG_PREEMPT.
That is a separate issue, but unnecessary calls to cond_resched() should of course be removed -- no argument there.
Thanx, Paul
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