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From: Petr Vorel <pvorel@suse.cz>
To: ltp@lists.linux.it
Subject: [LTP] [PATCH] read_all: limit per cpu nodes to first ten cpus
Date: Tue, 13 Apr 2021 15:57:41 +0200	[thread overview]
Message-ID: <YHWjVd8+y3jwRCxb@pevik> (raw)
In-Reply-To: <f776dd1a02dc16efa8aa80bbe6f9b55186dc82cd.1618321799.git.jstancek@redhat.com>

Hi Jan,

> Some per cpu sysfs entries have high lock contention and when
> this is combined with systems which have many CPUs (meaning they
> also have many per cpu sysfs entries) the test spends most of
> time on these nodes and occasionally also hits timeout.

> For example, these entries are largest contributor on HPE Apollo 70
> (aarch64, 256 CPUs):
>   /sys/kernel/tracing/per_cpu/cpu247/*
>   /sys/devices/system/cpu/cpu239/acpi_cppc/*

Acked-by: Petr Vorel <petr.vorel@gmail.com>

Kind regards,
Petr

  reply	other threads:[~2021-04-13 13:57 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-13 13:50 [LTP] [PATCH] read_all: limit per cpu nodes to first ten cpus Jan Stancek
2021-04-13 13:57 ` Petr Vorel [this message]
2021-04-15 11:44 ` Cyril Hrubis
2021-04-15 13:29   ` Jan Stancek

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