Messages in this thread | | | Date | Thu, 28 Nov 2013 15:47:14 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH]: exec: avoid propagating PF_NO_SETAFFINITY into userspace child |
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On Thu, Nov 28, 2013 at 09:38:48AM -0500, Tejun Heo wrote: > Hey, Peter. > > On Thu, Nov 28, 2013 at 03:31:45PM +0100, Peter Zijlstra wrote: > > But the WQ_UNBOUND thingies should be just that and should thus not have > > the NO_SETAFFINITY flag set because there is no valid reason to have it > > set. > > > > Regardless of whether the threads are shared between unbound workqueues > > or not. > > Hah? No, we do not want to allow userland to be able to set > affinities on any workqueue workers, period. That's just inviting > people to do weirdest things and then reporting things like "crypt > jobs on some of our 500 machines end up stuck on a single cpu once in > a while" which will eventually be tracked down to some weird shell > script setting affinity on workers doing something else. > > We really want to insulate workers and pool operation from userland. > e.g. unbound workqueues now default to per-NUMA affinity unless > explicitly told not to, which leads to better overall behavior for > most workloads. We do wanna keep those details from userland so that > they can be improved in the future too.
Bah, windows mentality of we know better.
If they do stupid they get stupid; the only thing we should be concerned about is correctness, they shouldn't be able to crash the system.
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