[PATCH v4 07/17] perf jevents: Sort json files entries

John Garry john.garry at huawei.com
Wed Aug 10 08:53:41 PDT 2022


On 10/08/2022 15:23, Ian Rogers wrote:
>> We sort the attributes of the events alphabetically by attribute name,
>> right? Is there any advantage in this? Do we need it for later?
> 
> The sort order is given by the tuple:
> (not j.desc is None, fix_none(j.topic), fix_none(j.name),
> fix_none(j.pmu), fix_none(j.metric_name))
> which is putting events with descriptions and topics before those
> without, then sorting by name, then pmu and finally metric_name. The
> advantage is that when we qsort alias events:
> https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/tree/tools/perf/util/pmu.c?h=perf/core#n1759
> the events are already in the sorted format, which should make the
> code faster -

ok, so can you mention that in the commit message? Just writing that you 
want to replicate cmp_sevent from pmu.c does not tell us this clearly.

 > it still has to qsort the sysfs events.

thanks,
John




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