On Tue, Oct 29, 2013 at 09:25:42AM +0100, Ingo Molnar wrote: > > * Neil Horman <nhor...@tuxdriver.com> wrote: > > > Heres my data for running the same test with taskset restricting > > execution to only cpu0. I'm not quite sure whats going on here, > > but doing so resulted in a 10x slowdown of the runtime of each > > iteration which I can't explain. As before however, both the > > parallel alu run and the prefetch run resulted in speedups, but > > the two together were not in any way addative. I'm going to keep > > playing with the prefetch stride, unless you have an alternate > > theory. > > Could you please cite the exact command-line you used for running > the test? > > Thanks, > > Ingo >
Sure it was this: for i in `seq 0 1 3` do echo $i > /sys/module/csum_test/parameters/module_test_mode taskset -c 0 perf stat --repeat 20 -C 0 -ddd perf bench sched messaging -- /root/test.sh done >> counters.txt 2>&1 where test.sh is: #!/bin/sh echo 1 > /sys/module/csum_test/parameters/test_fire As before, module_test_mode selects a case in a switch statement I added in do_csum to test one of the 4 csum variants we've been discusing (base, prefetch, parallel ALU or both), and test_fire is a callback trigger I use in the test module to run 100000 iterations of a checksum operation. As you requested, I ran the above on cpu 0 (-C 0 on perf and -c 0 on taskset), and I removed all irq affinity to cpu 0. Regards Neil -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
