LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Christian Borntraeger <borntraeger@de.ibm.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: peterz@infradead.org, bristot@redhat.com, bsegall@google.com,
	dietmar.eggemann@arm.com, greg@kroah.com,
	gregkh@linuxfoundation.org, joshdon@google.com,
	juri.lelli@redhat.com, linux-kernel@vger.kernel.org,
	linux@rasmusvillemoes.dk, mgorman@suse.de, mingo@kernel.org,
	valentin.schneider@arm.com, vincent.guittot@linaro.org,
	linux-s390@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: sched: Move SCHED_DEBUG sysctl to debugfs
Date: Tue, 27 Apr 2021 17:17:09 +0200	[thread overview]
Message-ID: <ae04549f-b009-9d90-d312-5c544f5a5e14@de.ibm.com> (raw)
In-Reply-To: <20210427110926.24f41fbb@gandalf.local.home>



On 27.04.21 17:09, Steven Rostedt wrote:
> On Tue, 27 Apr 2021 16:59:25 +0200
> Christian Borntraeger <borntraeger@de.ibm.com> wrote:
> 
>> Peter,
>>
>> I just realized that we moved away sysctl tunabled to debugfs in next.
>> We have seen several cases where it was benefitial to set
>> sched_migration_cost_ns to a lower value. For example with KVM I can
>> easily get 50% more transactions with 50000 instead of 500000.
>> Until now it was possible to use tuned or /etc/sysctl.conf to set
>> these things permanently.
>>
>> Given that some people do not want to have debugfs mounted all the time
>> I would consider this a regression. The sysctl tunable was always
>> available.
>>
>> I am ok with the "informational" things being in debugfs, but not
>> the tunables. So how do we proceed here?
> 
> Should there be a schedfs created?
> 
> This is the reason I created the tracefs file system, was to get the
> tracing code out of debugfs, as debugfs is a catch all for everything and
> can lead to poor and insecure interfaces that people do not want to add on
> systems that they still want tracing on.
> 
> Or perhaps we should add a "tunefs" for tunables that are stable interfaces
> that should not be in /proc but also not in debugfs.

Yes, a tunefs or schedfs could be considered a replacement for sysctl.
It will still break existing setups with kernel.sched* things in /etc/sysctl.conf
but at least there is a stable transition path.



  reply	other threads:[~2021-04-27 15:18 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-12 10:14 [PATCH v2 0/9] sched: Clean up SCHED_DEBUG Peter Zijlstra
2021-04-12 10:14 ` [PATCH v2 1/9] sched/numa: Allow runtime enabling/disabling of NUMA balance without SCHED_DEBUG Peter Zijlstra
2021-04-12 10:14 ` [PATCH v2 2/9] sched: Remove sched_schedstats sysctl out from under SCHED_DEBUG Peter Zijlstra
2021-04-16 15:53   ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2021-04-12 10:14 ` [PATCH v2 3/9] sched: Dont make LATENCYTOP select SCHED_DEBUG Peter Zijlstra
2021-04-16 15:53   ` [tip: sched/core] sched: Don't " tip-bot2 for Peter Zijlstra
2021-04-12 10:14 ` [PATCH v2 4/9] sched: Move SCHED_DEBUG sysctl to debugfs Peter Zijlstra
2021-04-15 16:29   ` [PATCH] sched/debug: Rename the sched_debug parameter to sched_debug_verbose Peter Zijlstra
2021-04-19 19:26     ` Josh Don
2021-04-16 15:53   ` [tip: sched/core] sched: Move SCHED_DEBUG sysctl to debugfs tip-bot2 for Peter Zijlstra
2021-04-27 14:59   ` Christian Borntraeger
2021-04-27 15:09     ` Steven Rostedt
2021-04-27 15:17       ` Christian Borntraeger [this message]
2021-04-28  8:47       ` Peter Zijlstra
2021-04-28  8:46     ` Peter Zijlstra
2021-04-28  8:54       ` Christian Borntraeger
2021-04-28  8:58         ` Christian Borntraeger
2021-04-28  9:25         ` Peter Zijlstra
2021-04-28  9:31           ` Christian Borntraeger
2021-04-28  9:42       ` Christian Borntraeger
2021-04-28 12:38         ` Peter Zijlstra
2021-04-28 14:49           ` Christian Borntraeger
2021-07-07 12:34           ` [PATCH 0/1] Improve yield (was: sched: Move SCHED_DEBUG sysctl to debugfs) Christian Borntraeger
2021-07-07 12:34             ` [PATCH 1/1] sched/fair: improve yield_to vs fairness Christian Borntraeger
2021-07-07 18:07               ` kernel test robot
2021-07-23  9:35               ` Mel Gorman
2021-07-23 12:36                 ` Christian Borntraeger
2021-07-23 16:21                   ` Mel Gorman
2021-07-26 18:41                     ` Christian Borntraeger
2021-07-26 19:32                       ` Mel Gorman
2021-07-27  6:59                         ` Christian Borntraeger
2021-07-27 18:57                       ` Benjamin Segall
2021-07-28 16:23                         ` Christian Borntraeger
2021-08-10  8:49                           ` Vincent Guittot
2021-07-27 13:29                     ` Peter Zijlstra
2021-07-27 13:33                 ` Peter Zijlstra
2021-07-27 14:31                   ` Mel Gorman
2021-04-12 10:14 ` [PATCH v2 5/9] sched,preempt: Move preempt_dynamic to debug.c Peter Zijlstra
2021-04-16 15:53   ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2021-04-12 10:14 ` [PATCH v2 6/9] debugfs: Implement debugfs_create_str() Peter Zijlstra
2021-04-16 15:53   ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2021-04-12 10:14 ` [PATCH v2 7/9] sched,debug: Convert sysctl sched_domains to debugfs Peter Zijlstra
2021-04-13 14:55   ` Valentin Schneider
2021-04-15  9:06     ` Peter Zijlstra
2021-04-15 12:16       ` Dietmar Eggemann
2021-04-15 12:34       ` Valentin Schneider
2021-04-15 13:02         ` Peter Zijlstra
2021-04-12 10:14 ` [PATCH v2 8/9] sched: Move /proc/sched_debug " Peter Zijlstra
2021-04-16 15:53   ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2021-04-12 10:14 ` [PATCH v2 9/9] sched,fair: Alternative sched_slice() Peter Zijlstra
2021-04-12 10:26   ` Peter Zijlstra
2021-04-16 15:53   ` [tip: sched/core] " tip-bot2 for Peter Zijlstra

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=ae04549f-b009-9d90-d312-5c544f5a5e14@de.ibm.com \
    --to=borntraeger@de.ibm.com \
    --cc=bristot@redhat.com \
    --cc=bsegall@google.com \
    --cc=dietmar.eggemann@arm.com \
    --cc=greg@kroah.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=joshdon@google.com \
    --cc=juri.lelli@redhat.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-s390@vger.kernel.org \
    --cc=linux@rasmusvillemoes.dk \
    --cc=mgorman@suse.de \
    --cc=mingo@kernel.org \
    --cc=peterz@infradead.org \
    --cc=rostedt@goodmis.org \
    --cc=valentin.schneider@arm.com \
    --cc=vincent.guittot@linaro.org \
    --subject='Re: sched: Move SCHED_DEBUG sysctl to debugfs' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).