linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Valentin Schneider <valentin.schneider@arm.com>
To: Peter Zijlstra <peterz@infradead.org>,
	mingo@kernel.org, mgorman@suse.de, juri.lelli@redhat.com,
	vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
	rostedt@goodmis.org, bsegall@google.com, bristot@redhat.com,
	joshdon@google.com
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, greg@kroah.com
Subject: Re: [PATCH 4/9] sched: Move SCHED_DEBUG to debugfs
Date: Wed, 07 Apr 2021 11:46:43 +0100	[thread overview]
Message-ID: <87blaqnzho.mognet@arm.com> (raw)
In-Reply-To: <20210326103935.025550243@infradead.org>

On 26/03/21 11:33, Peter Zijlstra wrote:
>  __read_mostly bool sched_debug_enabled;
>  
> +struct dentry *debugfs_sched;
> +
>  static __init int sched_init_debug(void)
>  {
> -	debugfs_create_file("sched_features", 0644, NULL, NULL,
> -			&sched_feat_fops);
> +	struct dentry __maybe_unused *numa;
> +
> +	debugfs_sched = debugfs_create_dir("sched", NULL);
> +
> +	debugfs_create_file("features", 0644, debugfs_sched, NULL, &sched_feat_fops);
> +	debugfs_create_bool("debug_enabled", 0644, debugfs_sched, &sched_debug_enabled);
> +

Could we kill this too? I'm probably biased because I've spent some amount
of time banging my head at topology problems, but this two-tiered debugging
setup (KCONFIG + cmdline or post-boot write) has always irked me.

I can't find the threads in a hurry, but ISTR justifications for keeping
this around were:
- Most distros have CONFIG_SCHED_DEBUG=y because knobs and ponies
- Topology debug prints are "too verbose"
- NUMA distance matrix processing gets slower

If we make it so distros stop / don't need to select CONFIG_SCHED_DEBUG,
then I don't think the above really stands anymore (also, sched_init_numa()
now has the same complexity regardless of sched_debug), and we could keep
everything under CONFIG_SCHED_DEBUG.

  parent reply	other threads:[~2021-04-07 10:47 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-26 10:33 [PATCH 0/9] sched: Clean up SCHED_DEBUG Peter Zijlstra
2021-03-26 10:33 ` [PATCH 1/9] sched/numa: Allow runtime enabling/disabling of NUMA balance without SCHED_DEBUG Peter Zijlstra
2021-03-26 10:33 ` [PATCH 2/9] sched: Remove sched_schedstats sysctl out from under SCHED_DEBUG Peter Zijlstra
2021-03-26 10:33 ` [PATCH 3/9] sched: Dont make LATENCYTOP select SCHED_DEBUG Peter Zijlstra
2021-03-26 10:33 ` [PATCH 4/9] sched: Move SCHED_DEBUG to debugfs Peter Zijlstra
2021-03-26 11:06   ` Greg KH
2021-04-07 10:46   ` Valentin Schneider [this message]
2021-04-07 12:26     ` Peter Zijlstra
2021-04-07 12:57       ` Valentin Schneider
2021-03-26 10:33 ` [PATCH 5/9] sched,preempt: Move preempt_dynamic to debug.c Peter Zijlstra
2021-03-26 10:33 ` [PATCH 6/9] debugfs: Implement debugfs_create_str() Peter Zijlstra
2021-03-26 11:05   ` Greg KH
2021-03-26 11:18     ` Peter Zijlstra
2021-03-26 11:30       ` Greg KH
2021-03-26 11:38         ` [PATCH v2 " Peter Zijlstra
2021-03-26 12:18           ` Greg KH
2021-03-26 12:53           ` Rasmus Villemoes
2021-03-26 12:57             ` Greg KH
2021-03-26 13:10               ` Rasmus Villemoes
2021-03-26 14:12                 ` Peter Zijlstra
2021-03-26 14:19                   ` Greg KH
2021-03-26 14:22             ` Peter Zijlstra
2021-03-26 14:58               ` Rasmus Villemoes
2021-03-26 15:19                 ` Peter Zijlstra
2021-03-27 10:41                   ` Greg KH
2021-03-26 14:50   ` [PATCH v3 " Peter Zijlstra
2021-03-27 10:42     ` Greg KH
2021-03-27 22:24   ` [PATCH " Al Viro
2021-03-28  0:33     ` Steven Rostedt
2021-03-26 10:33 ` [PATCH 7/9] sched,debug: Convert sysctl sched_domains to debugfs Peter Zijlstra
2021-03-26 13:11   ` Dietmar Eggemann
2021-04-07 10:46   ` Valentin Schneider
2021-04-07 12:18     ` Peter Zijlstra
2021-03-26 10:34 ` [PATCH 8/9] sched: Move /proc/sched_debug " Peter Zijlstra
2021-03-26 11:05   ` Greg KH
2021-03-26 10:34 ` [PATCH 9/9] sched,fair: Alternative sched_slice() Peter Zijlstra
2021-03-26 12:08   ` Dietmar Eggemann
2021-03-26 14:07     ` Peter Zijlstra
2021-03-26 15:37   ` Vincent Guittot
2021-03-26 18:30     ` 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=87blaqnzho.mognet@arm.com \
    --to=valentin.schneider@arm.com \
    --cc=bristot@redhat.com \
    --cc=bsegall@google.com \
    --cc=dietmar.eggemann@arm.com \
    --cc=greg@kroah.com \
    --cc=joshdon@google.com \
    --cc=juri.lelli@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mgorman@suse.de \
    --cc=mingo@kernel.org \
    --cc=peterz@infradead.org \
    --cc=rostedt@goodmis.org \
    --cc=vincent.guittot@linaro.org \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
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).