17/10/2023 12:27, Morten Brørup: > > >> From: Tummala, Sivaprasad <sivaprasad.tumm...@amd.com> > > >>> From: David Marchand <david.march...@redhat.com> > > >>> On Mon, Sep 25, 2023 at 5:11 PM Sivaprasad Tummala > > >>>> From: Sivaprasad Tummala <sivaprasad.tumm...@amd.com> > > >>>> > > >>>> By default, max lcores are limited to 128 for x86 platforms. > > >>>> On AMD EPYC processors, this limit needs to be increased to > > leverage > > >>>> all the cores. > > >>>> > > >>>> The patch adjusts the limit specifically for native compilation on > > >>>> AMD EPYC CPUs. > > >>>> > > >>>> Signed-off-by: Sivaprasad Tummala <sivaprasad.tumm...@amd.com> > > >>> > > >>> This patch is a revamp of > > >>> > > >> > > http://inbox.dpdk.org/dev/BY5PR12MB3681C3FC6676BC03F0B42CCC96789@BY5PR > > >>> 12MB3681.namprd12.prod.outlook.com/ > > >>> for which a discussion at techboard is supposed to have taken place. > > >>> But I didn't find a trace of it. > > >>> > > >>> One option that had been discussed in the previous thread was to > > >>> increase the max number of cores for x86. > > >>> I am unclear if this option has been properly evaluated/debatted. > > Here are the minutes from the previous techboard discussions: > [1]: http://inbox.dpdk.org/dev/YZ43U36bFWHYClAi@platinum/ > [2]: http://inbox.dpdk.org/dev/20211202112506.68acaa1a@hermes.local/ > > AFAIK, there has been no progress with dynamic max_lcores, so I guess the > techboard's conclusion still stands: > > There is no identified use-case where a single application requires more than > 128 lcores. If a case a use-case exists for a single application that uses > more than 128 lcores, the TB is ok to update the default config value. > > > >>> > > >>> Can the topic be brought again at techboard? > > >> > > >> Hi David, > > >> > > >> The patch is intended to detect AMD platforms and enable all CPU > > cores by default > > >> on native builds. > > This is done on native ARM builds, so why not on native X86 builds too? > > > >> > > >> As an optimization for memory footprint, users can override this by > > specifying "- > > >> Dmax_lcores" option based on DPDK lcores required for their usecases. > > >> > > >> Sure, will request to add this topic for discussion at techboard.
This is the summary of the techboard meeting: (see https://mails.dpdk.org/archives/dev/2023-October/279672.html) - There is some asks for more than 128 worker cores - Discussion about generally increasing the default max core count and trade-offs with memory consumption but this is longer term issue - Acceptance for the direction of this patch in the short term - Details of whether it should be for EPYC only or x86 to be figured out on mailing list So now let's figure out the details please. Suggestions?
