From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: Jan Stancek <jstancek@redhat.com>
Cc: linux-mm@kvack.org, lwoodman <lwoodman@redhat.com>,
Rafael Aquini <aquini@redhat.com>,
Andrea Arcangeli <aarcange@redhat.com>
Subject: Re: [bug?] mallocstress poor performance with THP on arm64 system
Date: Thu, 15 Feb 2018 12:02:46 +0300 [thread overview]
Message-ID: <20180215090246.qrsnncq3ajtbdlfy@node.shutemov.name> (raw)
In-Reply-To: <1847959563.1954032.1518649501357.JavaMail.zimbra@redhat.com>
On Wed, Feb 14, 2018 at 06:05:01PM -0500, Jan Stancek wrote:
> Hi,
>
> mallocstress[1] LTP testcase takes ~5+ minutes to complete
> on some arm64 systems (e.g. 4 node, 64 CPU, 256GB RAM):
> real 7m58.089s
> user 0m0.513s
> sys 24m27.041s
>
> But if I turn off THP ("transparent_hugepage=never") it's a lot faster:
> real 0m4.185s
> user 0m0.298s
> sys 0m13.954s
>
It's multi-threaded workload. My *guess* is that poor performance is due
to lack of ARCH_ENABLE_SPLIT_PMD_PTLOCK support on arm64.
--
Kirill A. Shutemov
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next prev parent reply other threads:[~2018-02-15 9:02 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1523287676.1950020.1518648233654.JavaMail.zimbra@redhat.com>
2018-02-14 23:05 ` Jan Stancek
2018-02-15 9:02 ` Kirill A. Shutemov [this message]
2018-02-16 17:30 ` Punit Agrawal
2018-02-15 18:40 ` Punit Agrawal
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