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 7/9] sched,debug: Convert sysctl sched_domains to debugfs
Date: Wed, 07 Apr 2021 11:46:32 +0100 [thread overview]
Message-ID: <87czv6nzhz.mognet@arm.com> (raw)
In-Reply-To: <20210326103935.264012208@infradead.org>
On 26/03/21 11:33, Peter Zijlstra wrote:
> Stop polluting sysctl, move to debugfs for SCHED_DEBUG stuff.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
> kernel/sched/debug.c | 255 ++++++++++--------------------------------------
> kernel/sched/sched.h | 2
> kernel/sched/topology.c | 1
> 3 files changed, 59 insertions(+), 199 deletions(-)
>
I do very much like to see a simple pair of seq_puts() replacing the
mess I put in there!
One comment below.
> --- a/kernel/sched/debug.c
> +++ b/kernel/sched/debug.c
> +void register_sched_domain_sysctl(void)
> +{
> + int cpu, i;
>
> if (!cpumask_available(sd_sysctl_cpus)) {
> if (!alloc_cpumask_var(&sd_sysctl_cpus, GFP_KERNEL))
> return;
> - }
> -
> - if (!init_done) {
> - init_done = true;
> - /* init to possible to not have holes in @cpu_entries */
> cpumask_copy(sd_sysctl_cpus, cpu_possible_mask);
> }
>
> - for_each_cpu(i, sd_sysctl_cpus) {
> - struct ctl_table *e = cpu_idx[i];
> + if (!sd_dentry)
> + sd_dentry = debugfs_create_dir("domains", debugfs_sched);
>
> - if (e->child)
> - sd_free_ctl_entry(&e->child);
> + for_each_cpu(cpu, sd_sysctl_cpus) {
> + struct sched_domain *sd;
> + struct dentry *d_cpu;
> + char buf[32];
> +
> + snprintf(buf, sizeof(buf), "cpu%d", cpu);
> + debugfs_remove(debugfs_lookup(buf, sd_dentry));
> + d_cpu = debugfs_create_dir(buf, sd_dentry);
> +
> + i = 0;
> + for_each_domain(cpu, sd) {
> + struct dentry *d_sd;
>
> - if (!e->procname) {
> - snprintf(buf, 32, "cpu%d", i);
> - e->procname = kstrdup(buf, GFP_KERNEL);
> - }
> - e->mode = 0555;
> - e->child = sd_alloc_ctl_cpu_table(i);
> + snprintf(buf, sizeof(buf), "domain%d", i);
> + d_sd = debugfs_create_dir(buf, d_cpu);
>
> - __cpumask_clear_cpu(i, sd_sysctl_cpus);
That seems to be the only place we cleared a CPU in that cpumask, and I
don't see its replacement, which would go against:
bbdacdfed2f5 ("sched/debug: Optimize sched_domain sysctl generation")
With my very limited understanding of debugfs and sysctl, it seems that
before we would have some stuff saved in sd_ctl_table and free/reinit just
the bits we needed. With debugfs_remove(), I think we wipe everything
clean, or did I read that wrong?
next prev 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
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 [this message]
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
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