Hi Cliff, On Wed, Oct 5, 2011 at 7:15 PM, Cliff Frey <[email protected]> wrote: > You could try adding BURST 10 or something to your FromDevice configuration > and see if that makes a difference. > You could also try changing tasks_per_iter (there is a top level handler, so > you could add "Script(write tasks_per_iter 300)" to your config). > I don't actually think that either of the above will make much difference... > as I believe that the click task should currently try and send 128 packets > each time it is scheduled (tasks_per_iter * BURST == 128 * 1 == 128). > However, the BURST one is definitely worth trying. > You could also try changing the "weight" on your ethernet driver, but that > also should default to 64 or higher, so I don't understand how/why so few > packets would be processed each time. > If you run ifconfig after the test, are there any error counters that are > very high?
Thanks for the hints. No, there aren't any error values on the NIC driver. If I turn off click (click-uninstall), then the packet rate rises up to approx 1,38 Mio pps (receive and drop by the kernel) and the context switch rate decreases to less than 1000 per sec. I tried the whole experiment multiple times - each time the same as described. Is the click kernel thread running in high-priority or RT mode? This could maybe explain the starvation of the ksoftirqd. Thanks, Daniel > Cliff > On Wed, Oct 5, 2011 at 8:58 AM, Daniel Borkmann <[email protected]> > wrote: >> >> On Wed, Oct 5, 2011 at 4:06 PM, Eddie Kohler <[email protected]> wrote: >> > I'm thinking probably we should do that automatically. >> >> Hmm, if someone wants to do debugging, then it might not work (since >> the syms are stripped), except you have a special target for debug, >> for instance. >> >> What I recently noticed running Click in kernelspace: the number of >> context switches per second is very high (... too high) on a high >> packet rate. More details: >> >> I have two machines Intel Core 2 Quad Q6600 CPU, 4 GB RAM, Intel >> 82566DC Ethernet Controller (e1000e driver). Both have Debian 6.0. One >> machine has a vanilla Linux 3.0 running pktgen with 64 Byte packets >> (max. load), the other one is running Linux 2.6.38 with click in >> kernelspace. Both are directly connected. The config is: >> source::FromDevice(eth0); drop::SimpleIdle; source->drop. I was >> measuring packets per second and the system's context switches per >> second, both gathered from procfs. The result was that I reached about >> 460k pps while having a context switch rate of about 200k cs/sec (!). >> (The high rate explains the rather low pps rate.) Running >> (multithreaded) click in userspace on top of Linux 3.0, I got about >> 545k pps and less than 1000 cs/sec. >> >> Has anyone measured similar values? Could it be, that the click kernel >> thread is pushing away CPU time for the ksoftirqd doing NAPI (sofirqs >> for RX) on the e1000e? >> >> Thanks, >> Daniel >> >> > >> > Eddie >> > >> > On 10/5/11 9:32 AM, Daniel Borkmann wrote: >> >> >> >> Hi Sandeep, >> >> >> >> thanks for your reply! :-) >> >> >> >> Stripping the debug symbols out of the module like ... >> >> >> >> root@xyz:~# strip -g /usr/local/lib/click.ko >> >> >> >> ... worked for me; I already was on the latest Git repository. >> >> >> >> Thanks, >> >> Daniel >> >> >> >> On Wed, Oct 5, 2011 at 3:14 PM, sandeep<[email protected]> wrote: >> >>> >> >>> I also had the same problem but it disappeared after I updated to the >> >>> latest >> >>> git repository. https://github.com/kohler/click/tarball/master >> >>> >> >>> Kind Regards, >> >>> Sandeep, >> >>> PhD Student, >> >>> CTVR - Trinity College Dublin >> >>> On Wed, Oct 5, 2011 at 1:36 PM, Daniel >> >>> Borkmann<[email protected]> >> >>> wrote: >> >>>> >> >>>> Hi list, >> >>>> I managed to build the patchless Click kernel version under 2.6.38, >> >>>> but insmod fails with the following: >> >>>> >> >>>> root@pc-10089:~# click-install forw.click >> >>>> insmod: error inserting '/usr/local/lib/click.ko': -1 Cannot allocate >> >>>> memory >> >>>> click-install: '/sbin/insmod /usr/local/lib/click.ko' failed >> >>>> >> >>>> Any ideas? Did anyone have same issues? >> >>>> >> >>>> Thanks, >> >>>> Daniel >> >>>> _______________________________________________ >> >>>> click mailing list >> >>>> [email protected] >> >>>> https://amsterdam.lcs.mit.edu/mailman/listinfo/click >> >>> >> >>> >> >> >> >> >> >> >> > >> >> >> >> -- >> Web: http://gnumaniacs.org >> >> _______________________________________________ >> click mailing list >> [email protected] >> https://amsterdam.lcs.mit.edu/mailman/listinfo/click > > -- Web: http://gnumaniacs.org _______________________________________________ click mailing list [email protected] https://amsterdam.lcs.mit.edu/mailman/listinfo/click
