From: Paul Thomas <pthomas8589@gmail.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-rt-users <linux-rt-users@vger.kernel.org>,
dunc.mcphie@gmail.com, Anders Roxell <anders.roxell@linaro.org>
Subject: Re: poor cyclictest results with 5.0 series rt for arm64
Date: Tue, 16 Jul 2019 20:44:53 -0400 [thread overview]
Message-ID: <CAD56B7eswTRxbeA8foXyVVZ7Bd+_y40dtOLkHxuAf4kVge7VDg@mail.gmail.com> (raw)
In-Reply-To: <alpine.DEB.2.21.1907170111160.1767@nanos.tec.linutronix.de>
On Tue, Jul 16, 2019 at 7:14 PM Thomas Gleixner <tglx@linutronix.de> wrote:
>
> On Tue, 16 Jul 2019, Paul Thomas wrote:
>
> > > > We do have trace data for a instance where cyclictest hit 5000 uS, but
> > > > the file is large 11MB, and I wasn't sure if I should directly attach
> > > > it to the email. What is the best way to post or send this?
> > >
> > > Can you upload the trace to some place? If you don't have storage, just use
> > > bugzilla.kernel.org and open a bug, attach it and post a reference.
> >
> > Hi Thomas,
> >
> > I've put the last 60k line of the trace on the bug report here:
> > https://bugzilla.kernel.org/show_bug.cgi?id=204189
> >
> > Just looking at the timestamp time of cyclicte-2778 I can see the last
> > two finish_task_switch calls are seperated by 5801 uS. Is just before
> > that the correct place to be looking?
>
> Right. If I'm reading it correctly, I think I know what's wrong. Can you
> please revert:
>
> 80e7f3b05365 ("arch/arm64: Add lazy preempt support")
>
> Either that patch is broken or it got broken on forward porting it from
> 4.19. Need to look with brain awake tomorrow.
Yes! this looks like it fixes it. The hash I see is slightly different:
b7f42e8fb48cbe38e4c2d0cab48309aadfa6d032
But the name was the same "arch/arm64: Add lazy preempt support"
I did a quick run with 5.0.19-rt11 with these results:
root@xu5:/opt/rt-tests# ./cyclictest -S -m -n -p 99 -i 200 -h 400 -D 900
# /dev/cpu_dma_latency set to 0us
policy: fifo: loadavg: 0.64 0.74 0.60 1/131 1931
T: 0 ( 1913) P:99 I:200 C:4499993 Min: 5 Act: 8 Avg: 7 Max: 20
T: 1 ( 1914) P:99 I:200 C:4499899 Min: 5 Act: 8 Avg: 7 Max: 16
T: 2 ( 1915) P:99 I:200 C:4499799 Min: 5 Act: 8 Avg: 7 Max: 17
T: 3 ( 1916) P:99 I:200 C:4499704 Min: 5 Act: 8 Avg: 7 Max: 16
We'll do some more testing tomorrow.
-Paul
next prev parent reply other threads:[~2019-07-17 0:45 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-12 11:18 poor cyclictest results with 5.0 series rt for arm64 Paul Thomas
[not found] ` <CAD56B7c2=95r7r-6tr0Mby8jSeuQPDNSd4LELnUw1LVRn9Rqew@mail.gmail.com>
2019-07-12 11:32 ` Paul Thomas
2019-07-16 20:24 ` Thomas Gleixner
2019-07-16 21:50 ` Paul Thomas
2019-07-16 23:14 ` Thomas Gleixner
2019-07-17 0:44 ` Paul Thomas [this message]
2019-07-17 8:03 ` Thomas Gleixner
2019-07-17 8:10 ` Thomas Gleixner
2019-07-17 9:02 ` Thomas Gleixner
2019-07-17 10:21 ` Thomas Gleixner
2019-07-17 22:28 ` Paul Thomas
2019-08-13 9:53 ` Sebastian Andrzej Siewior
2019-08-13 18:02 ` Paul Thomas
2019-08-14 11:26 ` Sebastian Andrzej Siewior
2019-08-14 16:17 ` [PATCH RT] arm64: preempt: Check preemption level before looking at lazy-preempt Sebastian Andrzej Siewior
2019-08-14 16:17 ` [PATCH RT] x86: " Sebastian Andrzej Siewior
2019-08-14 17:04 ` poor cyclictest results with 5.0 series rt for arm64 Paul Thomas
2019-08-15 8:29 ` Sebastian Andrzej Siewior
2019-08-15 12:33 ` John Ogness
2019-08-15 13:30 ` Paul Thomas
2019-08-15 13:42 ` Sebastian Andrzej Siewior
2019-08-15 13:52 ` Paul Thomas
2019-08-15 14:19 ` Sebastian Andrzej Siewior
2019-08-15 15:12 ` Paul Thomas
2019-08-15 15:15 ` Sebastian Andrzej Siewior
2019-08-15 15:31 ` Paul Thomas
2019-08-15 18:00 ` Paul Thomas
2019-08-15 18:57 ` Sebastian Andrzej Siewior
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