Date: Fri, 9 May 2014 13:49:14 -0400 From: John Baldwin <jhb@freebsd.org> To: Adrian Chadd <adrian@freebsd.org> Cc: Alexander Motin <mav@freebsd.org>, freebsd-current <freebsd-current@freebsd.org>, "freebsd-arch@freebsd.org" <freebsd-arch@freebsd.org> Subject: Re: [rfc] bind per-cpu timeout threads to each CPU Message-ID: <201405091349.14381.jhb@freebsd.org> In-Reply-To: <CAJ-VmonmrB7Z-PKH7P1DOJjSvFD_nRHqaiFJUuwvHoTUtiEVoQ@mail.gmail.com> References: <530508B7.7060102@FreeBSD.org> <CAJ-VmonUiSeCxnbYcjtWZ8uxa0c2ys5Za_GMLQenwu8zmEuFpQ@mail.gmail.com> <CAJ-VmonmrB7Z-PKH7P1DOJjSvFD_nRHqaiFJUuwvHoTUtiEVoQ@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Thursday, May 08, 2014 11:43:39 pm Adrian Chadd wrote: > Hi, > > I'd like to revisit this now. > > I'd like to commit this stuff as-is and then take some time to revisit > the catch-all softclock from cpu0 swi. It's more complicated than it > needs to be as it just assumes timeout_cpu == cpuid of cpu 0. So > there's no easy way to slide in a new catch-all softclock. > > Once that's done I'd like to then experiment with turning on the pcpu > tcp timer stuff and gluing that into the RSS CPU ID / netisr ID stuff. > > Thanks, To be clear, are you going to commit the change to bind all but CPU 0 to their CPU but let the "default" swi float for now? I think that is fine to commit, but I wouldn't want to bind the "default" swi for now. > -a > > > On 20 February 2014 13:48, Adrian Chadd <adrian@freebsd.org> wrote: > > On 20 February 2014 11:17, John Baldwin <jhb@freebsd.org> wrote: > > > >> (A further variant of this would be to divorce cpu0's swi from the > >> catch-all softclock and let the catch-all softclock float, but bind > >> all the per-cpu swis) > > > > I like this idea. If something (eg per-CPU TCP timers, if it's turned > > on) makes a very specific decision about the CPU then it should be > > fixed. Otherwise a lot of the underlying assumptions for things like > > RSS just aren't guaranteed to hold. > > > > It could also perhaps extend to some abstract pool of CPUs later, if > > we wanted to do things like one flowing swi per socket or whatnot when > > we start booting on 1024 core boxes... > > > > -a > -- John Baldwin
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201405091349.14381.jhb>