From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Vishal Chourasia <vishalc@linux.vnet.ibm.com>
Cc: ritesh.list@gmail.com, vschneid@redhat.com,
vincent.guittot@linaro.org, srikar@linux.vnet.ibm.com,
Peter Zijlstra <peterz@infradead.org>,
aneesh.kumar@linux.ibm.com, linux-kernel@vger.kernel.org,
sshegde@linux.ibm.com, mingo@redhat.com,
linuxppc-dev@lists.ozlabs.org
Subject: Re: sched/debug: CPU hotplug operation suffers in a large cpu systems
Date: Tue, 8 Nov 2022 13:24:39 +0100 [thread overview]
Message-ID: <Y2pKh3H0Ukvmfuco@kroah.com> (raw)
In-Reply-To: <Y2oozs/YgqqRV5hq@li-05afa54c-330e-11b2-a85c-e3f3aa0db1e9.ibm.com>
On Tue, Nov 08, 2022 at 03:30:46PM +0530, Vishal Chourasia wrote:
>
> Thanks Greg & Peter for your direction.
>
> While we pursue the idea of having debugfs based on kernfs, we thought about
> having a boot time parameter which would disable creating and updating of the
> sched_domain debugfs files and this would also be useful even when the kernfs
> solution kicks in, as users who may not care about these debugfs files would
> benefit from a faster CPU hotplug operation.
Ick, no, you would be adding a new user/kernel api that you will be
required to support for the next 20+ years. Just to get over a
short-term issue before you solve the problem properly.
If you really do not want these debugfs files, just disable debugfs from
your system. That should be a better short-term solution, right?
Or better yet, disable SCHED_DEBUG, why can't you do that?
thanks,
greg k-h
WARNING: multiple messages have this Message-ID (diff)
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Vishal Chourasia <vishalc@linux.vnet.ibm.com>
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: Tue, 8 Nov 2022 13:24:39 +0100 [thread overview]
Message-ID: <Y2pKh3H0Ukvmfuco@kroah.com> (raw)
In-Reply-To: <Y2oozs/YgqqRV5hq@li-05afa54c-330e-11b2-a85c-e3f3aa0db1e9.ibm.com>
On Tue, Nov 08, 2022 at 03:30:46PM +0530, Vishal Chourasia wrote:
>
> Thanks Greg & Peter for your direction.
>
> While we pursue the idea of having debugfs based on kernfs, we thought about
> having a boot time parameter which would disable creating and updating of the
> sched_domain debugfs files and this would also be useful even when the kernfs
> solution kicks in, as users who may not care about these debugfs files would
> benefit from a faster CPU hotplug operation.
Ick, no, you would be adding a new user/kernel api that you will be
required to support for the next 20+ years. Just to get over a
short-term issue before you solve the problem properly.
If you really do not want these debugfs files, just disable debugfs from
your system. That should be a better short-term solution, right?
Or better yet, disable SCHED_DEBUG, why can't you do that?
thanks,
greg k-h
next prev parent reply other threads:[~2022-11-08 12:25 UTC|newest]
Thread overview: 38+ 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
2022-10-18 11:04 ` Greg Kroah-Hartman
2022-10-26 6:37 ` Vishal Chourasia
2022-10-26 6:37 ` Vishal Chourasia
2022-10-26 7:02 ` Greg Kroah-Hartman
2022-10-26 7:02 ` Greg Kroah-Hartman
2022-10-26 9:10 ` Peter Zijlstra
2022-10-26 9:10 ` Peter Zijlstra
2022-11-08 10:00 ` Vishal Chourasia
2022-11-08 10:00 ` Vishal Chourasia
2022-11-08 12:24 ` Greg Kroah-Hartman [this message]
2022-11-08 12:24 ` Greg Kroah-Hartman
2022-11-08 14:51 ` Srikar Dronamraju
2022-11-08 14:51 ` Srikar Dronamraju
2022-11-08 15:38 ` Greg Kroah-Hartman
2022-11-08 15:38 ` Greg Kroah-Hartman
2022-12-12 19:17 ` Phil Auld
2022-12-12 19:17 ` Phil Auld
2022-12-13 2:17 ` kernel test robot
2022-12-13 2:17 ` kernel test robot
2022-12-13 6:23 ` Greg Kroah-Hartman
2022-12-13 6:23 ` Greg Kroah-Hartman
2022-12-13 13:22 ` Phil Auld
2022-12-13 13:22 ` Phil Auld
2022-12-13 14:31 ` Greg Kroah-Hartman
2022-12-13 14:31 ` Greg Kroah-Hartman
2022-12-13 14:45 ` Phil Auld
2022-12-13 14:45 ` Phil Auld
2023-01-19 15:31 ` Phil Auld
2023-01-19 15:31 ` Phil Auld
2022-12-13 23:41 ` Michael Ellerman
2022-12-13 23:41 ` Michael Ellerman
2022-12-14 2:26 ` Phil Auld
2022-12-14 2:26 ` Phil Auld
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