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From: Stefan Liebler <stli@linux.ibm.com>
To: libc-alpha@sourceware.org
Subject: Re: [PATCH v3] malloc: Remove bin scanning from memalign (bug 30723)
Date: Tue, 19 Sep 2023 16:32:39 +0200	[thread overview]
Message-ID: <9a9934d7-8174-cf18-994e-5a751475108f@linux.ibm.com> (raw)
In-Reply-To: <87a5uxtwaq.fsf@oldenburg.str.redhat.com>

On 11.08.23 17:48, Florian Weimer via Libc-alpha wrote:
> On the test workload (mpv --cache=yes with VP9 video decoding), the
> bin scanning has a very poor success rate (less than 2%).  The tcache
> scanning has about 50% success rate, so keep that.
> 
> Update comments in malloc/tst-memalign-2 to indicate the purpose
> of the tests.  Even with the scanning removed, the additional
> merging opportunities since commit 542b1105852568c3ebc712225ae78b
> ("malloc: Enable merging of remainders in memalign (bug 30723)")
> are sufficient to pass the existing large bins test.
Hi,

on s390x, I've observed these test-fails starting with this commit:
FAIL: malloc/tst-memalign-2
FAIL: malloc/tst-memalign-2-malloc-hugetlb1

With this output:
error: tst-memalign-2.c:158: not true: count > LN / 2
error: 1 test failures

Note, that I only see the fails if /proc/sys/kernel/randomize_va_space
is set to 0. Then I get count=3; LN=8;

If randomize_va_space is set to 2, the test passes and I get count=5; LN=8;

Is s390x the only architecture where we get this failure?

Bye,
Stefan

  reply	other threads:[~2023-09-19 14:37 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-11 15:48 Florian Weimer
2023-09-19 14:32 ` Stefan Liebler [this message]
2023-09-19 17:35   ` Florian Weimer
2023-09-20 14:35     ` Stefan Liebler
2023-09-20 15:31       ` Florian Weimer
2023-09-21 13:05         ` Stefan Liebler

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