On Wed, Feb 10, 2010 at 10:10:25PM +1100, Anton Blanchard wrote: > > Nick Piggin discovered that lwsync barriers around locks were faster than > isync > on 970. That was a long time ago and I completely dropped the ball in testing > his patches across other ppc64 processors. > > Turns out the idea helps on other chips. Using a microbenchmark that > uses a lot of threads to contend on a global pthread mutex (and therefore a > global futex), POWER6 improves 8% and POWER7 improves 2%. I checked POWER5 > and while I couldn't measure an improvement, there was no regression.
Ah, good to see this one come back. I also tested tbench over localhost btw which actually did show some speedup on the G5. BTW. this was the last thing left: http://www.mail-archive.com/linuxppc-dev@lists.ozlabs.org/msg29738.html Don't know if you took a look at that again, but maybe it's worth looking at. Hmm, we do actually seem to be growing number of smp_mb* calls in core kernel too. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
