Re: [dpdk-dev] [PATCH 0/4] Extend --lcores to run on cores > RTE_MAX_LCORE

[Luca Boccassi <bluca@debian.org>]

On Tue, 2020-06-09 at 16:30 +0000, Song, Keesang wrote:
> [AMD Public Use]
> 
> Hi Kevin and Luca,
> 
> We are still waiting for the response.
> Can you help on this for the backports in 18.11 and 19.11?
> It would work for our customers even with changing the default value of ' CONFIG_RTE_MAX_LCORE' to 256 in common_base file in 18.11 and 19.11.
> 
> Thanks,
> Keesang

How to send patches for inclusion in LTS releases if not already
backported is documented here:

https://core.dpdk.org/contribute/#send

If you do the work to backport and test, on the surface it seems fine
to have those in 19.11.4

> -----Original Message-----
> From: Song, Keesang 
> Sent: Monday, June 1, 2020 3:54 PM
> To: Thomas Monjalon <thomas@monjalon.net>
> Cc: David Marchand <david.marchand@redhat.com>; dev@dpdk.org; aconole@redhat.com; ferruh.yigit@intel.com; bluca@debian.org; ktraynor@redhat.com; bruce.richardson@intel.com; honnappa.nagarahalli@arm.com; drc@linux.vnet.ibm.com; stable@dpdk.org; Aman Kumar <aman.kumar@vvdntech.in>; Grimm, Jon <Jon.Grimm@amd.com>
> Subject: RE: [dpdk-dev] [PATCH 0/4] Extend --lcores to run on cores > RTE_MAX_LCORE
> 
> [AMD Public Use]
> 
> Thanks Thomas for the response.
> For a correction, the patchwork has not been submitted for the current LTS release, 19.11.2, but was merged into 20.02 and onward. 
> The reason I brought this again was to address LTS users and many other application based on the LTS releases(18.11 & 19.11).
> Since I found many of our customers and users are still relying on the latest LTS version, I'm seeking an aid for adding this change into at least 19.11, LTS branch.
> We could argue that this is actually not a bug, in a way, it's inconvenient for Openstack or cloud deployed DPDK application since it's often inapt to change the base config and recompile the max lcore limit.
> If backporting is still not a preferred way(pushing this patchwork into 19.11), then can we instead consider changing only the default value of ' CONFIG_RTE_MAX_LCORE' to 256 in common_base file?
> 
> # Compile Environment Abstraction Layer
> #
> CONFIG_RTE_MAX_LCORE=128 --> 256
> 
> I'd appreciate if anyone can advise me know what we can do about this to move forward.
> 
> -----Original Message-----
> From: Thomas Monjalon <thomas@monjalon.net>
> Sent: Monday, June 1, 2020 2:23 PM
> To: Song, Keesang <Keesang.Song@amd.com>
> Cc: David Marchand <david.marchand@redhat.com>; dev@dpdk.org; aconole@redhat.com; ferruh.yigit@intel.com; bluca@debian.org; ktraynor@redhat.com; bruce.richardson@intel.com; honnappa.nagarahalli@arm.com; drc@linux.vnet.ibm.com; stable@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH 0/4] Extend --lcores to run on cores > RTE_MAX_LCORE
> 
> [CAUTION: External Email]
> 
> 29/05/2020 05:05, Song, Keesang:
> > Hi Thomas & David,
> > 
> > We haven't got the final status on this patch, and I don't see this change even from the latest LTS 20.04 repo.
> > So I'd like to confirm whether this patch has been safely submitted to the main upstream.
> > Can you check the status of that commit?
> > 
> > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpatc
> > hwork.dpdk.org%2Fpatch%2F63507%2F&amp;data=02%7C01%7CKeesang.Song%40am
> > d.com%7Cd71ea9aca917447dfb3e08d80671f34c%7C3dd8961fe4884e608e11a82d994
> > e183d%7C0%7C0%7C637266433776198364&amp;sdata=1EgxevCILVMMLgyQC%2FzaWYJ
> > XJ%2BOijs0Rtym1TA0VS28%3D&amp;reserved=0
> 
> As you can see below, there is a pending question:
>         "is it a new feature or a fix?"
> 
> Kevin and Luca are the arbiters for the backports in 18.11 and 19.11.
> 
> 
> > -----Original Message-----
> > From: Thomas Monjalon <thomas@monjalon.net>
> > Sent: Friday, February 21, 2020 12:04 AM
> > 
> > Hi,
> > 
> > 21/01/2020 01:24, Thomas Monjalon:
> > > 02/12/2019 16:35, David Marchand:
> > > > We are currently stuck with no option but recompile a DPDK if the 
> > > > system has more cores than RTE_MAX_LCORE.
> > > > A bit of a pity when you get a system with more than 200+ cores 
> > > > and your testpmd has been built and packaged with RTE_MAX_LCORE == 128.
> > > > 
> > > > The --lcores does not need to care about the underlying cores, 
> > > > remove this limitation.
> > > > David Marchand (4):
> > > >   eal/windows: fix cpuset macro name
> > > >   eal: do not cache lcore detection state
> > > >   eal: display all detected cores at startup
> > > >   eal: remove limitation on cpuset with --lcores
> > > 
> > > The patches look good but it is very hard to review parsing code (last patch).
> > > We will better experience corner cases after merging.
> > > 
> > > Applied for -rc1, thanks
> > 
> > This patch was merged in 20.02.
> > We don't have any feedback about issues so it's probably working fine.
> > 
> > It is solving a problem for running DPDK on machines having a lot of cores.
> > Now the difficult question: is it a new feature or a fix?
> > Should we backport this patchset?