From: Ramana Radhakrishnan <ramana.gcc@googlemail.com>
To: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
Cc: Richard Earnshaw <Richard.Earnshaw@arm.com>,
Ramana Radhakrishnan <ramana.radhakrishnan@foss.arm.com>,
Christophe Lyon <christophe.lyon@linaro.org>,
GCC Patches <gcc-patches@gcc.gnu.org>, nd <nd@arm.com>,
Kyrylo Tkachov <Kyrylo.Tkachov@arm.com>
Subject: Re: [PATCH][ARM] Switch to default sched pressure algorithm
Date: Sat, 12 Oct 2019 00:58:00 -0000 [thread overview]
Message-ID: <CAJA7tRYRtATabn+0=QSZcJoqiOjyM=2BH1SoCtGOZ5MvEiUVyw@mail.gmail.com> (raw)
In-Reply-To: <VI1PR0801MB2127EFEA50E18D03FB13A55A83970@VI1PR0801MB2127.eurprd08.prod.outlook.com>
On Fri, Oct 11, 2019 at 6:19 PM Wilco Dijkstra <Wilco.Dijkstra@arm.com> wrote:
>
> Hi Ramana,
>
> > Can you see what happens with the Cortex-A8 or Cortex-A9 schedulers to
> > spread the range across some v7-a CPUs as well ? While they aren't that popular today I
> > would suggest you look at them because the defaults for v7-a are still to use the
> > Cortex-A8 scheduler and the Cortex-A9 scheduler might well also get used in places given
> > the availability of hardware.
>
> The results are practically identical to Cortex-A53 and A57 - there is a huge codesize win
> across the board on SPEC2006, there isn't a single benchmark that is larger (ie. more
> spilling).
>
> > I'd be happy to move this forward if you could show if there is no *increase* in spills
> > for the same range of benchmarks that you are doing for the Cortex-A8 and Cortex-A9
> > schedulers.
>
> There certainly isn't. I don't think results like these could be any more one-sided, it's a
> significant win for every single benchmark, both for codesize and performance!
>
Ok go ahead - please be sensitive to testsuite regressions.
Ramana
> What isn't clear is whether something has gone horribly wrong in the scheduler which
> could be fixed/reverted, but as it is right now I can't see it being useful at all. This means
> we should also reevaluate whether pressure scheduling now hurts AArch64 too.
>
> Cheers,
> Wilco
next prev parent reply other threads:[~2019-10-12 0:52 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-29 17:20 Wilco Dijkstra
2019-07-30 9:29 ` Christophe Lyon
2019-07-30 9:34 ` Ramana Radhakrishnan
2019-07-30 12:53 ` Richard Earnshaw (lists)
2019-07-30 15:16 ` Wilco Dijkstra
2019-10-10 21:38 ` Ramana Radhakrishnan
2019-10-11 17:33 ` Wilco Dijkstra
2019-10-11 21:44 ` Wilco Dijkstra
2019-10-12 1:07 ` Ramana Radhakrishnan
2019-10-12 0:58 ` Ramana Radhakrishnan [this message]
2019-10-15 18:05 ` Christophe Lyon
2019-10-16 12:51 ` Wilco Dijkstra
2019-10-16 15:43 ` Richard Earnshaw (lists)
2019-12-19 13:26 ` Wilco Dijkstra
2019-08-19 15:53 ` Wilco Dijkstra
2019-09-02 12:11 ` Wilco Dijkstra
2019-09-09 17:05 ` Wilco Dijkstra
2019-10-10 17:25 ` Wilco Dijkstra
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