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

From: Alexander Shishkin
Date: Wed Aug 30 2017 - 06:19:09 EST


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.

Regards,
--
Alex