On Tue, Jul 30, 2019 at 1:38 PM Johan Källström <[email protected]> wrote: > The CPU failsafe is nice to have as you could set the thread affinity to > offline cpus.
Created a "dpdk" cpuset and put cpus 4-7 into it (my system is mono numa with 8 cpus) # cd /sys/fs/cgroup/cpuset/ # mkdir dpdk # cd dpdk # echo 4-7 > cpuset.cpus # echo 0 > cpuset.mems Disabled cpu 5. # echo 0 > /sys/bus/cpu/devices/cpu5/online Put my shell that starts testpmd in this dpdk cpuset # echo 4439 > tasks EAL refuses an offline core when parsing the thread affinities and this did not change. $ ./master/app/testpmd --master-lcore 0 --lcores '(0,7)@(7,4,5)' --log-level *:debug --no-huge --no-pci -m 512 -- -i --total-num-mbufs=2048 EAL: Detected lcore 0 as core 0 on socket 0 EAL: Detected lcore 1 as core 1 on socket 0 EAL: Detected lcore 2 as core 2 on socket 0 EAL: Detected lcore 3 as core 3 on socket 0 EAL: Detected lcore 4 as core 0 on socket 0 EAL: Detected lcore 6 as core 2 on socket 0 EAL: Detected lcore 7 as core 3 on socket 0 EAL: Support maximum 128 logical core(s) by configuration. EAL: Detected 7 lcore(s) EAL: Detected 1 NUMA nodes EAL: core 5 unavailable EAL: invalid parameter for --lcores What did I miss? > > Maybe also add the example I gave you to trigger the bug? > https://bugs.dpdk.org/show_bug.cgi?id=322#c12 I managed to reproduce your error with the setup above (without relying on the cset tool that is not available on rhel afaics), I can add it to the commitlog yes. > This also shows how to set the default_affinity mask and proves that the > calculation will result in threads inside the cpuset on Linux. > > /Johan > > On tis, 2019-07-30 at 11:35 +0200, David Marchand wrote: > > When using -l/-c options, each lcore is mapped to a physical cpu in a > > 1:1 fashion. > > On the contrary, when using --lcores, each lcore has its own cpuset > > Use "thread affinity" instead of cpuset when we talk about setting the thread > affinity. > > I know that the term cpuset is used in the data structure, but it is not a > cpuset as described by 'man cpuset' (on Linux). This comment can be seen as > cosmetic, but I think that it could be good to have a clear definitions to > minimize confusion. Indeed, using cpuset is inappropriate. I will update the commitlog and the comment. -- David Marchand
