Re: perf top for arm64?
From: Jiri Olsa
Date: Tue Dec 10 2019 - 12:08:53 EST
On Tue, Dec 10, 2019 at 04:52:52PM +0000, John Garry wrote:
> On 10/12/2019 16:36, Jiri Olsa wrote:
> > On Tue, Dec 10, 2019 at 04:13:49PM +0000, John Garry wrote:
> > > Hi all,
> > >
> > > I find to my surprise that "perf top" does not work for arm64:
> > >
> > > root@ubuntu:/home/john/linux# tools/perf/perf top
> > > Couldn't read the cpuid for this machine: No such file or directory
> Hi Jirka,
> > there was recent change that check on cpuid and quits:
> > 608127f73779 perf top: Initialize perf_env->cpuid, needed by the per arch annotation init routine
> ok, this is new code. I obviously didn't check the git history...
> But, apart from this, there are many other places where get_cpuid() is
> called. I wonder what else we're missing out on, and whether we should still
> add it.
right, I was just wondering how come vendor events are working for you,
but realized we have get_cpuid_str being called in there ;-)
I think we should add it as you have it prepared already,
could you post it with bigger changelog that would explain
where it's being used for arm?