From: Vishal Chourasia <vishalc@linux.vnet.ibm.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
linux-kernel@vger.kernel.org, mingo@redhat.com,
vincent.guittot@linaro.org, vschneid@redhat.com,
srikar@linux.vnet.ibm.com, sshegde@linux.ibm.com,
linuxppc-dev@lists.ozlabs.org, ritesh.list@gmail.com,
aneesh.kumar@linux.ibm.com
Subject: Re: sched/debug: CPU hotplug operation suffers in a large cpu systems
Date: Wed, 26 Oct 2022 12:07:01 +0530 [thread overview]
Message-ID: <Y1jVjX9FUuUilcjA@li-05afa54c-330e-11b2-a85c-e3f3aa0db1e9.ibm.com> (raw)
In-Reply-To: <Y06ISBWhJflnV+NI@kroah.com>
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On Tue, Oct 18, 2022 at 01:04:40PM +0200, Greg Kroah-Hartman wrote:
> Why do you need to? What tools require these debugfs files to be
> present?
We are not entirely sure what applications (if any) might be using this interface.
> And if you only have 7-8 files per CPU, that does not seem like a lot of
> files overall (14000-16000)? If you only offline 1 cpu, how is removing
> 7 or 8 files a bottleneck? Do you really offline 1999 cpus for a 2k
> system?
It's 7-8 files per domain per cpu, so, in a system with approx 2k cpus and five
domains, the total file count goes above 70k-80k files. And, when we offline 1
CPU, the entire directory is rebuilt, resulting in creation of all the files
again.
Thanks
-- vishal.c
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next prev parent reply other threads:[~2022-10-26 6:38 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-17 13:10 sched/debug: CPU hotplug operation suffers in a large cpu systems Vishal Chourasia
2022-10-17 14:19 ` Peter Zijlstra
2022-10-17 14:54 ` Greg Kroah-Hartman
2022-10-18 10:37 ` Vishal Chourasia
2022-10-18 11:04 ` Greg Kroah-Hartman
2022-10-26 6:37 ` Vishal Chourasia [this message]
2022-10-26 7:02 ` Greg Kroah-Hartman
2022-10-26 9:10 ` Peter Zijlstra
2022-11-08 10:00 ` Vishal Chourasia
2022-11-08 12:24 ` Greg Kroah-Hartman
2022-11-08 14:51 ` Srikar Dronamraju
2022-11-08 15:38 ` Greg Kroah-Hartman
2022-12-12 19:17 ` Phil Auld
2022-12-13 2:17 ` kernel test robot
2022-12-13 6:23 ` Greg Kroah-Hartman
2022-12-13 13:22 ` Phil Auld
2022-12-13 14:31 ` Greg Kroah-Hartman
2022-12-13 14:45 ` Phil Auld
2023-01-19 15:31 ` Phil Auld
2022-12-13 23:41 ` Michael Ellerman
2022-12-14 2:26 ` Phil Auld
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