>-----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.
> > >> 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. Regards, Bhanu Prakash. > >Thanks, >-- >fbl _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
