2016-08-18 14:20 GMT-07:00 Bodireddy, Bhanuprakash < bhanuprakash.bodire...@intel.com>:
> >-----Original Message----- > >From: Flavio Leitner [mailto:f...@sysclose.org] > >Sent: Thursday, August 18, 2016 2:15 PM > >To: Bodireddy, Bhanuprakash <bhanuprakash.bodire...@intel.com> > >Cc: Daniele Di Proietto <diproiet...@ovn.org>; dev@openvswitch.org > >Subject: Re: [ovs-dev] [PATCH V6] netdev-dpdk: Set pmd thread priority > > > >On Tue, Aug 16, 2016 at 02:30:04PM +0000, Bodireddy, Bhanuprakash wrote: > >> >-----Original Message----- > >> >From: Daniele Di Proietto [mailto:diproiet...@ovn.org] > >> >Sent: Tuesday, August 16, 2016 1:44 AM > >> >To: Bodireddy, Bhanuprakash <bhanuprakash.bodire...@intel.com> > >> >Cc: dev@openvswitch.org; Flavio Leitner <f...@sysclose.org> > >> >Subject: Re: [PATCH V6] netdev-dpdk: Set pmd thread priority > >> > > >> >I found a crash if apply this patch, "dpdk-lcore-mask" is not set and > >> >"-c 0x1" is passed to "dpdk-extra". > >> My bad, I didn't test with dpdk-extra options. I see that the crash was > due to > >strtol. > >> > >> >Also, I believe Flavio had a comment on the previous version of this > >> >patch. Would it be enough to use setpriority(2)? > >> I sent out my comments in another mail. I agree to Flavio's suggestion > >> as this seems less dangerous and is guaranteed to work even in case of > >> misconfiguration. I tested this approach and have a concern with > >setpriority(). > >> > >> To apply the new nice value to the thread, thread id is needed and due > >> to absence of glibc wrapper for gettid, I have to use > syscall(SYS_gettid). I > >want to know if this is acceptable in OVS or better way to handle this? > >> > >> Void ovs_numa_thread_setpriority(int nice OVS_UNUSED) { .... > >> #if defined(__linux__) && defined(SYS_gettid) > >> pid_t tid = syscall(SYS_gettid); > >> err = setpriority(PRIO_PROCESS, tid, nice); > >> .... > >> #endif > >> } > > > >I don't know a better way to implement this and it seems ovs-numa.c > already > >has some ifdefs specific to linux. > > > >Do you know if this problem happen on BSD? > I don't know if this is a problem on BSD. I searched a bit and found BSD > code using "syscall(SYS_thr_self, &tid)" > to retrieve the tid. > > The dummy ovs-numa works (and thus compile) everywhere, for pmd tests, but the module only works on linux. I think it's fine to implement something only for linux and return EOPNOTSUPP (only if dummy is not enabled) for everything else. I think passing 0 as thread_id to setpriority() changes the current thread priority, so there's probably no need for SYS_gettid. > > > > > >> Without priority patch: > >> > >> $ ps -eLo tid,pri,psr,comm | grep -e lcore -e revalidator -e > ovs-vswitchd -e > >pmd > >> 22509 19 4 ovs-vswitchd > >> 22512 19 5 lcore-slave-5 > >> 22513 19 6 lcore-slave-6 > >> 22514 19 7 lcore-slave-7 > >> 22589 19 4 revalidator37 > >> 22590 19 4 revalidator52 > >> 22591 19 4 revalidator42 > >> 22592 19 4 revalidator38 > >> 22593 19 4 revalidator39 > >> 22594 19 4 revalidator45 > >> 22595 19 4 revalidator53 > >> 22596 19 4 revalidator54 > >> 22598 19 4 pmd61 [Default priority] > >> > >> With priority patch: > >> > >> $ ps -eLo tid,pri,psr,comm | grep -e lcore -e revalidator -e > ovs-vswitchd -e > >pmd > >> 24879 19 4 ovs-vswitchd > >> 24881 19 5 lcore-slave-5 > >> 24882 19 6 lcore-slave-6 > >> 24883 19 7 lcore-slave-7 > >> 24951 19 4 revalidator55 > >> 24952 19 4 revalidator37 > >> 24953 19 4 revalidator52 > >> 24954 19 4 revalidator42 > >> 24955 19 4 revalidator38 > >> 24956 19 4 revalidator39 > >> 24957 19 4 revalidator45 > >> 24958 19 4 revalidator53 > >> 24964 39 4 pmd61 [Higher priority set] > > > >Looks good, so if you affinity your bash to the CPU running > >pmd61 thread, are you able to use it? > > Yes, I tested this case and there seems to be no problem here. > So there's no need to make it exclusive with dpdk-lcore-mask anymore, right? Thanks, Daniele > > Regards, > Bhanu Prakash. > > > > >Thanks, > >-- > >fbl > > _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
