From: Juri Lelli <juri.lelli@arm.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Juri Lelli <juri.lelli@gmail.com>,
Clark Williams <williams@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [RFC][PATCH 3/3 v2] sched: Add bandwidth ratio to /proc/sched_debug
Date: Wed, 3 Feb 2016 17:56:46 +0000 [thread overview]
Message-ID: <20160203175646.GD12132@e106622-lin> (raw)
In-Reply-To: <20160203165955.184691855@goodmis.org>
Hi,
On 03/02/16 11:57, Steven Rostedt wrote:
> From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>
>
> Playing with SCHED_DEADLINE and cpusets, I found that I was unable to create
> new SCHED_DEADLINE tasks, with the error of EBUSY as if the bandwidth was
> already used up. I then realized there wa no way to see what bandwidth is
> used by the runqueues to debug the issue.
>
> By adding the dl_bw->bw and dl_bw->total_bw to the output of the deadline
> info in /proc/sched_debug, this allows us to see what bandwidth has been
> reserved and where a problem may exist.
>
> For example, before the issue we see the ratio of the bandwidth:
>
> # cat /proc/sys/kernel/sched_rt_runtime_us
> 950000
> # cat /proc/sys/kernel/sched_rt_period_us
> 1000000
>
> # grep dl /proc/sched_debug
> dl_rq[0]:
> .dl_nr_running : 0
> .dl_bw->bw : 996147
> .dl_bw->total_bw : 0
> dl_rq[1]:
> .dl_nr_running : 0
> .dl_bw->bw : 996147
> .dl_bw->total_bw : 0
> dl_rq[2]:
> .dl_nr_running : 0
> .dl_bw->bw : 996147
> .dl_bw->total_bw : 0
> dl_rq[3]:
> .dl_nr_running : 0
> .dl_bw->bw : 996147
> .dl_bw->total_bw : 0
> dl_rq[4]:
> .dl_nr_running : 0
> .dl_bw->bw : 996147
> .dl_bw->total_bw : 0
> dl_rq[5]:
> .dl_nr_running : 0
> .dl_bw->bw : 996147
> .dl_bw->total_bw : 0
> dl_rq[6]:
> .dl_nr_running : 0
> .dl_bw->bw : 996147
> .dl_bw->total_bw : 0
> dl_rq[7]:
> .dl_nr_running : 0
> .dl_bw->bw : 996147
> .dl_bw->total_bw : 0
>
I think this is already quite useful. But, do you think we can also
display information about the root_domain (like the span for example)?
Or do we have that some place else already?
Thanks,
- Juri
next prev parent reply other threads:[~2016-02-03 17:56 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-03 16:56 [RFC][PATCH 0/3 v2] sched: Display deadline bandwidth and other SCHED_DEBUG clean up Steven Rostedt
2016-02-03 16:56 ` [RFC][PATCH 1/3 v2] sched: Move sched_feature file setup into debug.c Steven Rostedt
2016-02-03 16:57 ` [RFC][PATCH 2/3 v2] sched: Move sched_domain_sysctl to debug.c Steven Rostedt
2016-02-03 16:57 ` [RFC][PATCH 3/3 v2] sched: Add bandwidth ratio to /proc/sched_debug Steven Rostedt
2016-02-03 17:56 ` Juri Lelli [this message]
2016-02-03 18:10 ` Steven Rostedt
2016-02-10 15:13 ` [RFC][PATCH 0/3 v2] sched: Display deadline bandwidth and other SCHED_DEBUG clean up Steven Rostedt
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