Re: [PATCH v6 1/3] perf/core: use rb trees for pinned/flexible groups

From: Alexander Shishkin
Date: Wed Aug 30 2017 - 07:15:27 EST


Alexey Budankov <alexey.budankov@xxxxxxxxxxxxxxx> writes:

> On 30.08.2017 13:18, Alexander Shishkin wrote:
>> Alexey Budankov <alexey.budankov@xxxxxxxxxxxxxxx> writes:
>>
>>>>> Iterating cpu specific subtree like this:
>>>>>
>>>>> #define for_each_group_event(event, group, cpu, pmu, field) \
>>>>> for (event = rb_entry_safe(group_first(group, cpu, pmu), \
>>>>> typeof(*event), field); \
>>>>> event && event->cpu == cpu && event->pmu == pmu; \
>>>>> event = rb_entry_safe(rb_next(&event->field), \
>>>>> typeof(*event), field))
>>>>
>>>> Afaict, this assumes that you are also ordering on event->pmu, which
>>>> should be reflected in your _less function. And also assuming that
>>>> group_first() is doing the right thing. Can we see the code?
>>>
>>> I didn't do ordering by PMU for this patch set. Yet more I implemented
>>> groups_first() like this:
>>
>> Your iterator (quoted above) begs to differ.
>
> What do you specifically mean? I am doing iterations like this:

I mean the code that you've shown before, which is quoted above. It's
difficult to tell why something's not working if you don't show the
code.

Regards,
--
Alex