Re: perf top for arm64?

From: John Garry
Date: Tue Dec 10 2019 - 12:18:02 EST

On 10/12/2019 17:08, Jiri Olsa wrote:
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?

ok, I can look to do that.

But, as you know, we still need to fix perf top for other architectures affected.