On Wed, 2012-10-31 at 18:10 +0000, Attilio Rao wrote: > On Wed, Oct 31, 2012 at 6:07 PM, Attilio Rao <atti...@freebsd.org> wrote: > > Author: attilio > > Date: Wed Oct 31 18:07:18 2012 > > New Revision: 242402 > > URL: http://svn.freebsd.org/changeset/base/242402 > > > > Log: > > Rework the known mutexes to benefit about staying on their own > > cache line in order to avoid manual frobbing but using > > struct mtx_padalign. > > Interested developers can now dig and look for other mutexes to > convert and just do it. > Please, however, try to enclose a description about the benchmark > which lead you believe the necessity to pad the mutex and possibly > some numbers, in particular when the lock belongs to structures or the > ABI itself. > > Next steps involve porting the same mtx(9) changes to rwlock(9) and > port pvh global pmap lock to rwlock_padalign. > > Thanks, > Attilio > >
Doesn't this padding to cache line size only help x86 processors in an SMP kernel? I was expecting to see some #ifdef SMP so that we don't pay a big price for no gain in small-memory ARM systems and such. But maybe I'm misunderstanding the reason for the padding. -- Ian _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
