Date: Fri, 6 Sep 2013 00:37:33 +0200 From: Zbigniew Bodek <zbb@semihalf.com> To: Jia-Shiun Li <jiashiun@gmail.com> Cc: "freebsd-arm@freebsd.org" <freebsd-arm@freebsd.org> Subject: Re: stream benchmarking on RPi Message-ID: <CAG7dG%2Bxn9yCCPn30SXWnC6ppYkoWCjTKhBtgwcH-s46wHAdCJA@mail.gmail.com> In-Reply-To: <CAHNYxxNtBcjD_Khq1_pYCMdPwZJmQ0M_GTmcaGWtoLOJkz_86g@mail.gmail.com> References: <CAHNYxxNtBcjD_Khq1_pYCMdPwZJmQ0M_GTmcaGWtoLOJkz_86g@mail.gmail.com>
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2013/9/5 Jia-Shiun Li <jiashiun@gmail.com> > Hi all, > > just did a brief test using stream, the memory bandwidth benchmark, on > RPi with Raspbian and FreeBSD. Share these info to see if someone > might think of it useful. > > FreeBSD is faster at copying. I guess that must be attributed to > recent VM and/or superpage commits. I remembered it to be under > 300MB/s months before. On the other hand, scale, add, and triad are > significantly slower. Anyone have clues or any wild guesses? > > > Below the only compiler option given for cc/gcc is -O3. > > Raspbian 2013-07-26 (lk 3.6, gcc 4.6): > ------------------------------------------------------------- > Function Best Rate MB/s Avg time Min time Max time > Copy: 257.3 0.062703 0.062189 0.063824 > Scale: 205.1 0.079135 0.077993 0.082000 > Add: 284.1 0.085253 0.084480 0.088597 > Triad: 274.3 0.087799 0.087501 0.087940 > ------------------------------------------------------------- > > FreeBSD 10.0-CURRENT r255120 w/ cc(clang): > ------------------------------------------------------------- > Function Best Rate MB/s Avg time Min time Max time > Copy: 365.5 0.045321 0.043779 0.052929 > Scale: 31.2 0.531028 0.513082 0.550906 > Add: 68.5 0.367295 0.350467 0.391310 > Triad: 26.9 0.902672 0.893316 0.908908 > ------------------------------------------------------------- > > FreeBSD 10.0-CURRENT r255120 w/ gcc (4.2.1): > ------------------------------------------------------------- > Function Best Rate MB/s Avg time Min time Max time > Copy: 264.6 0.063977 0.060470 0.081000 > Scale: 31.0 0.535830 0.516093 0.551035 > Add: 46.7 0.534768 0.514323 0.553834 > Triad: 23.1 1.047644 1.038968 1.066887 > ------------------------------------------------------------- > > Hello Jia-Shiun. Thanks for your effort in testing. I am actually in the middle of superpages tests and another benchmark and set of results will be very helpful especially for comparison. Just for the record: did you enable superpages for your kernel? SP are not yet enabled by default, therefore one needs to set vm.pmap.sp_enabled to non-zero value in loader.conf (if you are using loader) or set this value in src by editing sys/arm/arm/pmap-v6.c -> sp_enabled. Nevertheless I've made short tests on Armada XP (clang). I used two array sizes (default and 2 x default). I also made few runs to ensure that the results are steady. Please check below (improvement in copy can be seen but from what one can observe via sysctl vm.pmap.section not so many superpages are "requested" during the test): Array size = 10000000 (elements) ================================ sp disabled ------------------------------------------------------------- Function Best Rate MB/s Avg time Min time Max time Copy: 1311.9 0.124910 0.121956 0.126486 Scale: 64.2 2.546568 2.493977 2.570808 Add: 112.1 2.163666 2.140962 2.205463 Triad: 51.3 4.683770 4.675176 4.689565 sp enabled ------------------------------------------------------------- Function Best Rate MB/s Avg time Min time Max time Copy: 1368.9 0.119831 0.116878 0.121894 Scale: 64.6 2.527607 2.476270 2.551667 Add: 112.9 2.147966 2.125261 2.189840 Triad: 51.6 4.654865 4.647609 4.662289 Array size = 20000000 (elements) ================================ sp disabled ------------------------------------------------------------- Function Best Rate MB/s Avg time Min time Max time Copy: 1271.2 0.257928 0.251738 0.260991 Scale: 64.2 5.092455 4.987830 5.139630 Add: 112.0 4.331419 4.287459 4.416701 Triad: 51.3 9.366274 9.349165 9.379344 sp enabled ------------------------------------------------------------- Function Best Rate MB/s Avg time Min time Max time Copy: 1333.3 0.250755 0.240014 0.253216 Scale: 64.5 5.065569 4.963166 5.114160 Add: 112.4 4.312079 4.268610 4.395812 Triad: 51.6 9.325673 9.309094 9.338787 Best regards Zbigniew Bodek
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