Messages in this thread | | | Date | Thu, 4 Jan 2018 22:48:09 +0100 | From | Pavel Machek <> | Subject | Re: [RFC PATCH] asm/generic: introduce if_nospec and nospec_barrier |
| |
On Thu 2018-01-04 21:23:59, Alan Cox wrote: > On Thu, 4 Jan 2018 21:39:24 +0100 (CET) > Jiri Kosina <jikos@kernel.org> wrote: > > > On Thu, 4 Jan 2018, Alan Cox wrote: > > > > > You never go from one user process to another except via the kernel. We > > > have no hardware scheduling going on. That means that if the kernel > > > and/or CPU imposes the correct speculation barriers you can't attack > > > anyone but yourself. > > > > So how does this work on HT with the shared BTB? There is no context > > switch (and hence no IBPB) happening between the threads sharing it. > > > > If you are paranoid in that case you either need to schedule things that > trust each other together or disable the speculation while that situation > occurs. However the kernel is always in the position to make that > decision.
Actually... I'm not paranoid but would like to run flightgear on one core (smt cpu #0), with smt cpu#1 being idle, while running compilations on second core (smt cpus #2 and #3).
Is there easy way to do that? Pavel
-- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html [unhandled content-type:application/pgp-signature] | |