On 1/24/23 16:52, Kevin Traynor wrote: > On 08/01/2023 03:55, Cheng Li wrote: >> In my test, if one logical core is pinned to PMD thread while the >> other logical(of the same physical core) is not. The PMD >> performance is affected the by the not-pinned logical core load. >> This maks it difficult to estimate the loads during a dry-run. >> >> Signed-off-by: Cheng Li <lic...@chinatelecom.cn> >> --- >> Documentation/topics/dpdk/pmd.rst | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/Documentation/topics/dpdk/pmd.rst >> b/Documentation/topics/dpdk/pmd.rst >> index 9006fd4..b220199 100644 >> --- a/Documentation/topics/dpdk/pmd.rst >> +++ b/Documentation/topics/dpdk/pmd.rst >> @@ -312,6 +312,10 @@ If not set, the default variance improvement threshold >> is 25%. >> when all PMD threads are running on cores from a single NUMA node. In >> this >> case cross-NUMA datapaths will not change after reassignment. >> + For the same reason, please ensure that the pmd threads are pinned to >> SMT >> + siblings if HyperThreading is enabled. Otherwise, PMDs within a NUMA may >> + not have the same performance.
Uhm... Am I reading this wrong or this note suggests to pin PMD threads to SMT siblings? It sounds like that's the opposite of what you were trying to say. Siblings are sharing the same physical core, so if some PMDs are pinned to siblings, the load prediction can not work correctly. Nit: s/pmd/PMD/ Best regards, Ilya Maximets. >> + >> The minimum time between 2 consecutive PMD auto load balancing iterations >> can >> also be configured by:: >> > > I don't think it's a hard requirement as siblings should not impact as much > as cross-numa might but it's probably good advice in general. > > Acked-by: Kevin Traynor <ktray...@redhat.com> > > _______________________________________________ > dev mailing list > d...@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-dev > _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
