linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: Juri Lelli <juri.lelli@redhat.com>
Cc: mingo@redhat.com, rostedt@goodmis.org,
	linux-kernel@vger.kernel.org, luca.abeni@santannapisa.it,
	claudio@evidence.eu.com, tommaso.cucinotta@santannapisa.it,
	bristot@redhat.com, mathieu.poirier@linaro.org,
	lizefan@huawei.com, cgroups@vger.kernel.org
Subject: Re: [PATCH v5 5/5] cpuset: Rebuild root domain deadline accounting information
Date: Tue, 25 Sep 2018 14:32:22 +0200	[thread overview]
Message-ID: <20180925123222.GA29985@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20180903142801.20046-6-juri.lelli@redhat.com>

On Mon, Sep 03, 2018 at 04:28:01PM +0200, Juri Lelli wrote:
> +/*
> + * Called with cpuset_mutex held (rebuild_sched_domains())
> + * Called with hotplug lock held (rebuild_sched_domains_locked())
> + * Called with sched_domains_mutex held (partition_and_rebuild_domains())

Isn't that what we have lockdep_assert_held() for?

> + */
> +static void rebuild_root_domains(void)
> +{
> +	struct cpuset *cs = NULL;
> +	struct cgroup_subsys_state *pos_css;
> +
> +	rcu_read_lock();
> +
> +	/*
> +	 * Clear default root domain DL accounting, it will be computed again
> +	 * if a task belongs to it.
> +	 */
> +	dl_clear_root_domain(&def_root_domain);
> +
> +	cpuset_for_each_descendant_pre(cs, pos_css, &top_cpuset) {
> +
> +		if (cpumask_empty(cs->effective_cpus)) {
> +			pos_css = css_rightmost_descendant(pos_css);
> +			continue;
> +		}
> +
> +		css_get(&cs->css);
> +
> +		rcu_read_unlock();

That looks really dodgy, but I suppose the comment near
css_next_descendant_pre() spells out that this is in fact OK.

> +		update_tasks_root_domain(cs);
> +
> +		rcu_read_lock();
> +		css_put(&cs->css);
> +	}
> +	rcu_read_unlock();
> +}

  reply	other threads:[~2018-09-25 12:32 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-03 14:27 [PATCH v5 0/5] sched/deadline: fix cpusets bandwidth accounting Juri Lelli
2018-09-03 14:27 ` [PATCH v5 1/5] sched/topology: Adding function partition_sched_domains_locked() Juri Lelli
2018-09-03 14:27 ` [PATCH v5 2/5] sched/core: Streamlining calls to task_rq_unlock() Juri Lelli
2018-09-03 14:27 ` [PATCH v5 3/5] cgroup/cpuset: make callback_lock raw Juri Lelli
2018-09-25 14:34   ` Juri Lelli
2018-11-07  9:59     ` Juri Lelli
2018-11-07 15:53     ` Tejun Heo
2018-11-07 16:38       ` Juri Lelli
2018-11-08 11:22         ` Juri Lelli
2018-11-08 19:11         ` Waiman Long
2018-11-09 10:34           ` Juri Lelli
2018-09-03 14:28 ` [PATCH v5 4/5] sched/core: Prevent race condition between cpuset and __sched_setscheduler() Juri Lelli
2018-10-03 19:42   ` Steven Rostedt
2018-10-04  9:04     ` Juri Lelli
2018-11-08 15:49       ` Waiman Long
2018-11-08 16:23         ` Juri Lelli
2018-09-03 14:28 ` [PATCH v5 5/5] cpuset: Rebuild root domain deadline accounting information Juri Lelli
2018-09-25 12:32   ` Peter Zijlstra [this message]
2018-09-25 13:07     ` Juri Lelli
2018-09-25 12:53   ` Peter Zijlstra
2018-09-25 13:08     ` Juri Lelli
2018-09-25  8:14 ` [PATCH v5 0/5] sched/deadline: fix cpusets bandwidth accounting Juri Lelli

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=20180925123222.GA29985@hirez.programming.kicks-ass.net \
    --to=peterz@infradead.org \
    --cc=bristot@redhat.com \
    --cc=cgroups@vger.kernel.org \
    --cc=claudio@evidence.eu.com \
    --cc=juri.lelli@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=lizefan@huawei.com \
    --cc=luca.abeni@santannapisa.it \
    --cc=mathieu.poirier@linaro.org \
    --cc=mingo@redhat.com \
    --cc=rostedt@goodmis.org \
    --cc=tommaso.cucinotta@santannapisa.it \
    --subject='Re: [PATCH v5 5/5] cpuset: Rebuild root domain deadline accounting information' \
    /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).