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From: "Bernhard M. Wiedemann" <>
To: Ian Rogers <>, Ben Hutchings <>
Cc: Arnaldo Carvalho de Melo <>,,
Subject: Re: [PATCH] perf jevents: Sort list of input files
Date: Mon, 20 Mar 2023 22:30:00 +0100	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

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On 20/03/2023 21.48, Ian Rogers wrote:
> I think this may already be addressed by sorting prior to output:
> Could you confirm?

Hi Ian,

I was testing on 6.2.6 which includes that patch and it was still affected.
The trouble with sorting at the end is, that there can be influences of 
ordering in earlier processing steps, that don't get ironed out by the 
sort later.

Some more experimenting showed that only the ftw scandir needed sorting, 
which allows to further simplify the patch to

      """Replicate the directory/file walking behavior of C's ...
-    for item in os.scandir(path):
+    for item in sorted(os.scandir(path), key=lambda e:
        action(parents, item)

Without the patch, a random diff in pmu-events.c starts with
-static const struct compact_pmu_event pme_amdzen2[] = {
+static const struct compact_pmu_event pme_silvermont[] = {

While I'm testing on scratch ext4 filesystems where dirindex causes 
randomness, you could also use the disorderfs FUSE-filesystem with its 
shuffle mode to give you random order.

Bernhard M.

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  reply	other threads:[~2023-03-20 21:31 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-20 20:18 [PATCH] perf jevents: Sort list of input files Bernhard M. Wiedemann
2023-03-20 20:48 ` Ian Rogers
2023-03-20 21:30   ` Bernhard M. Wiedemann [this message]
2023-03-20 21:39     ` Ian Rogers
2023-03-20 22:24     ` Arnaldo Carvalho de Melo
2023-03-21  6:30       ` Bernhard M. Wiedemann
2023-03-21 12:38         ` Arnaldo Carvalho de Melo

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