Re: [PATCH] perf: Fix sibling iteration

[Alexey Budankov]

On 16.03.2018 13:31, Peter Zijlstra wrote:
> On Fri, Mar 16, 2018 at 12:59:34PM +0300, Alexey Budankov wrote:
>> Hi,
>> On 15.03.2018 20:01, Peter Zijlstra wrote:
>>> Subject: perf: Fix sibling iteration
>>> From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
>>> Date: Thu Mar 15 17:36:56 CET 2018
>>>
>>> Mark noticed that the change to sibling_list changed some iteration
>>> semantics; because previously we used group_list as list entry,
>>> sibling events would always have an empty sibling_list.
>>>
>>> But because we now use sibling_list for both list head and list entry,
>>> siblings will report as having siblings.
>>>
>>> Fix this with a custom for_each_sibling_event() iterator.
>>>
>>> Suggested-by: Mark Rutland <mark.rutland@xxxxxxx>
>>> Reported-by: Mark Rutland <mark.rutland@xxxxxxx>
>>> Fixes: 8343aae66167 ("perf/core: Remove perf_event::group_entry")
>>> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
>>> ---
>>
>> Applied to tip repo and run testing on Fedora 27/x86_64 (client skylake 8 cores):
> 
> There is at least one more known issue with that patch, but neither Mark
> nor me could reproduce so far, so we don't know if we're right about the
> cause.

Please share more information regarding the issue. I am ready to help.

Thanks,
Alexey