linux-kernel - Re: [PATCH v4 07/17] perf jevents: Sort json files entries

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <3f0579b3-2d58-c8c6-3e3f-ff966ad09bad@huawei.com>
Date:   Wed, 10 Aug 2022 16:53:41 +0100
From:   John Garry <john.garry@...wei.com>
To:     Ian Rogers <irogers@...gle.com>
CC:     Will Deacon <will@...nel.org>, James Clark <james.clark@....com>,
        "Mike Leach" <mike.leach@...aro.org>, Leo Yan <leo.yan@...aro.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        "Arnaldo Carvalho de Melo" <acme@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        "Alexander Shishkin" <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...nel.org>,
        Namhyung Kim <namhyung@...nel.org>,
        Andi Kleen <ak@...ux.intel.com>,
        "Zhengjun Xing" <zhengjun.xing@...ux.intel.com>,
        Ravi Bangoria <ravi.bangoria@....com>,
        Kan Liang <kan.liang@...ux.intel.com>,
        Adrian Hunter <adrian.hunter@...el.com>,
        <linux-kernel@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-perf-users@...r.kernel.org>,
        Stephane Eranian <eranian@...gle.com>
Subject: Re: [PATCH v4 07/17] perf jevents: Sort json files entries

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