lkml.org 
[lkml]   [2019]   [Dec]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: perf top for arm64?
From
Date
Hi John,

On 2019/12/11 1:08, 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?

I've also seen the similar problem when I was looking to add support
for 'perf kvm stat' on arm64 [1] (which though got stuck due to some
other reasons for a very long time :(

It would be great if your patch can address this issue!


[1] https://lore.kernel.org/patchwork/patch/1087531/


Thanks,
Zenghui

\
 
 \ /
  Last update: 2019-12-11 03:37    [W:0.127 / U:1.152 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site