Re: Question about using the perf c2c in UMA system

[Ian Rogers <irogers@google.com>]

On Mon, Apr 29, 2024 at 2:43 PM Leo Yan <leo.yan@linux.dev> wrote:
>
> Hi Baisheng,
>
> On Mon, Apr 08, 2024 at 10:52:59AM +0000, ?????? (Baisheng Gao) wrote:
> > Hi linux-perf-users,
> >
> > My perf tool version is 6.6, and I compiled it to run on an Android system.
> > The problem is:
> >
> > # ./perf c2c report
> > Failed setup nodes
> >
> > According to the articles on the Internet, it seems that the perf c2c is only supported
> > in NUMA system. However, the cache false sharing does not exist only in NUMA, and
> > the UMA system has also the problem. So I wonder how to support perf c2c in UMA.
>
> The log above is related with parsing NUMA nodes, but this doesn't
> mean 'perf c2c' must run on NUMA system. My understanding is both
> x86_64 (memory event) and Arm64 (SPE) support 'perf c2c' not only on
> NUMA.

The lack of SPE on most ARM hardware really is a pain. Can we add a
better error message to make it clearer to users that they need a
neoverse CPU? :-)

Thanks,
Ian

> Thanks,
> Leo
>