On Sun, Jul 31, 2016 at 7:03 AM, Adrian Chadd <adrian.ch...@gmail.com> wrote:
> Did you test on any 1, 2, 4, 8 cpu machines? just to see if there are
> any performance degredations on lower count CPUs?
The adaptive spinning path will never run on a uniprocessor. Except
for potential i-cache displacement you're not going to actually see
any effect unless there is substantial contention. You'll need all
threads consistently contending for the same lock. A potential
workload to exercise this would be to run ncpu threads sending small
UDP packets on a driver with a legacy mutex protected IFQ interface.
> Also, yeah, the MOD operator in each loop could get spendy on older
> CPUs (eg my MIPS CPUs, older ARM stuff, etc.) Is it possible to
> achieve much the same autotuning with pow2 operations instead of
> firstname.lastname@example.org mailing list
> To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
email@example.com mailing list
To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"