John Baldwin wrote: > > On Monday 05 December 2005 03:45 pm, John Baldwin wrote: > > jhb 2005-12-05 20:45:24 UTC > > > > FreeBSD src repository > > > > Modified files: > > sys/kern subr_witness.c > > sys/sys _lock.h lock.h > > Log: > > Tweak witness handling of lock object to shave 2 pointers off of each > > lock object (and thus off of each mutex and sx lock): > > > > ... > > > > With these changes, struct mtx shrinks from 36 to 28 bytes on 32-bit > > platforms and from 72 to 56 bytes on 64-bit platforms. Note that this > > commit will completely and utterly destroy the kernel ABI, so no MFC. > > > > Tested on: alpha, amd64, i386, sparc64 > > andre@ reported a 5% perf increase from this change on at least one network > benchmark.
I tested only with WITNESS enabled and there it did in fact make a 5% difference on a HTTP connection performance test over the loopback interface. It is mostly limited by lock performance and I was measuring only 33 instructions on average between two lock operations (lock or unlock). -- Andre _______________________________________________ cvs-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/cvs-all To unsubscribe, send any mail to "[EMAIL PROTECTED]"