From: Peter Zijlstra <peterz@infradead.org>
To: luca abeni <luca.abeni@unitn.it>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
linux-kernel@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
Juri Lelli <juri.lelli@arm.com>,
Claudio Scordino <claudio@evidence.eu.com>
Subject: Re: [RFC v3 1/6] Track the active utilisation
Date: Tue, 6 Dec 2016 09:35:01 +0100 [thread overview]
Message-ID: <20161206083501.GW3092@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20161205233005.54275bd6@sweethome>
On Mon, Dec 05, 2016 at 11:30:05PM +0100, luca abeni wrote:
> Hi Peter,
>
> On Fri, 18 Nov 2016 15:23:59 +0100
> Peter Zijlstra <peterz@infradead.org> wrote:
> [...]
> > u64 running_bw;
> >
> > static void add_running_bw(struct sched_dl_entity *dl_se, struct
> > dl_rq *dl_rq) {
> > u64 old = dl_rq->running_bw;
> >
> > dl_rq->running_bw += dl_se->dl_bw;
> > SCHED_WARN_ON(dl_rq->running_bw < old); /* overflow */
> > }
> >
> > static void sub_running_bw(struct sched_dl_entity *dl_se, struct
> > dl_rq *dl_rq) {
> > u64 old = dl_rq->running_bw;
> >
> > dl_rq->running_bw -= dl_se->dl_bw;
> > SCHED_WARN_ON(dl_rq->running_bw > old); /* underflow */
> > }
>
> I wanted to change "SCHED_WARN_ON(dl_rq->running_bw > old); /*
> underflow */" into "if (SCHED_WARN_ON(...)) dl_rq->running_bw = 0" (to
> avoid using nonsensical "running_bw" values), but I see that
> "SCHED_WARN_ON()" cannot be used inside an if (this seems to be a
> difference respect to "SCHED_WARN()").
There's a SCHED_WARN? Did you mean to say WARN_ON()?
And yes, mostly by accident I think, I'm not a big user of that pattern
and neglected it when I did SCHED_WARN_ON().
> This is because of the definition used when CONFIG_SCHED_DEBUG is not
> defined (I noticed the issue when testing with random kernel
> configurations).
I'm fine changing the definition, just find something that works. The
current ((void)(x)) thing was to avoid unused complaints -- although I'm
not sure there were any.
next prev parent reply other threads:[~2016-12-06 8:35 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-24 14:06 [RFC v3 0/6] CPU reclaiming for SCHED_DEADLINE Luca Abeni
2016-10-24 14:06 ` [RFC v3 1/6] Track the active utilisation Luca Abeni
2016-10-25 9:09 ` Daniel Bristot de Oliveira
2016-10-25 9:29 ` luca abeni
2016-10-25 13:58 ` Steven Rostedt
2016-10-25 18:04 ` Luca Abeni
2016-11-18 14:23 ` Peter Zijlstra
2016-11-18 15:10 ` luca abeni
2016-11-18 15:28 ` Peter Zijlstra
2016-11-18 16:42 ` Steven Rostedt
2016-12-05 22:30 ` luca abeni
2016-12-06 8:35 ` Peter Zijlstra [this message]
2016-12-06 8:57 ` luca abeni
2016-12-06 13:47 ` luca abeni
2016-11-01 16:45 ` Juri Lelli
2016-11-01 21:10 ` luca abeni
2016-11-08 17:56 ` Juri Lelli
2016-11-08 18:17 ` Luca Abeni
2016-11-08 18:53 ` Juri Lelli
2016-11-08 19:09 ` Luca Abeni
2016-11-08 20:02 ` Juri Lelli
2016-11-09 15:25 ` luca abeni
2016-11-09 16:29 ` luca abeni
2016-11-18 14:55 ` Peter Zijlstra
2016-11-18 13:55 ` Peter Zijlstra
2016-11-18 15:06 ` luca abeni
2016-10-24 14:06 ` [RFC v3 2/6] Improve the tracking of " Luca Abeni
2016-11-01 16:46 ` Juri Lelli
2016-11-01 21:46 ` luca abeni
2016-11-02 2:35 ` luca abeni
2016-11-10 10:04 ` Juri Lelli
2016-11-10 11:56 ` Juri Lelli
2016-11-10 12:15 ` luca abeni
2016-11-10 12:34 ` Juri Lelli
2016-11-10 12:45 ` luca abeni
2016-11-02 2:41 ` luca abeni
2016-11-18 15:36 ` Peter Zijlstra
2016-11-18 15:56 ` luca abeni
2016-11-18 15:47 ` Peter Zijlstra
2016-11-18 16:06 ` luca abeni
2016-11-18 18:49 ` Peter Zijlstra
2016-10-24 14:06 ` [RFC v3 3/6] Fix the update of the total -deadline utilization Luca Abeni
2016-10-24 14:06 ` [RFC v3 4/6] GRUB accounting Luca Abeni
2016-10-24 14:06 ` [RFC v3 5/6] Do not reclaim the whole CPU bandwidth Luca Abeni
2016-10-24 14:06 ` [RFC v3 6/6] Make GRUB a task's flag Luca Abeni
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