On Sat, May 10, 2014 at 12:53:37AM +0000, Adrian Chadd wrote: > Author: adrian > Date: Sat May 10 00:53:36 2014 > New Revision: 265792 > URL: http://svnweb.freebsd.org/changeset/base/265792 > > Log: > Add in support to optionally pin the swi threads. > > Under enough load, the swi's can actually be preempted and migrated > to other currently free cores. When doing RSS experiments, this lead > to the per-CPU TCP timers not lining up any more with the RX CPU said > flows were ending up on, leading to increased lock contention. > > Since there was a little pushback on flipping them on by default, > I've left the default at "don't pin." > > The other less obvious problem here is that the default swi > is also the same as the destination swi for CPU #0. So if one > pins the swi on CPU #0, there's no default floating swi. > > A nice future project would be to create a separate swi for > the "default" floating swi, as well as per-CPU swis that are > (optionally) pinned.
MFC planed? I have 10.0 box with aprox. 16Gbit TCP at peak. _______________________________________________ svn-src-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
