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From: Frederic Konrad <fred.konrad@greensocs.com>
To: "Alexander Spyridakis" <a.spyridakis@virtualopensystems.com>,
	"Alex Bennée" <alex.bennee@linaro.org>
Cc: mttcg@listserver.greensocs.com,
	Peter Maydell <peter.maydell@linaro.org>,
	Mark Burton <mark.burton@greensocs.com>,
	QEMU Developers <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] [RFC PATCH] target-arm/psci.c: wake up sleeping CPUs (MTTCG)
Date: Thu, 25 Jun 2015 14:43:39 +0200	[thread overview]
Message-ID: <558BF77B.2020803@greensocs.com> (raw)
In-Reply-To: <CAJRNFKLd7CTwrVtn5EEHKUW40aKVWY4JkbwvsUKeGPYpeyULEg@mail.gmail.com>

On 25/06/2015 01:55, Alexander Spyridakis wrote:
> On 24 June 2015 at 17:34, Alex Bennée <alex.bennee@linaro.org> wrote:
>> Testing with Alexander's bare metal syncronisation tests fails in MTTCG
>> leaving one CPU spinning forever waiting for the second CPU to wake up.
>> We simply need to poke the halt_cond once we have processed the PSCI
>> power on call.
> Thanks Alex. Works for me, also with qemu_cpu_kick(target_cpu_state)
> as Paolo mentioned.
>
> The test seems to stress the current multi-threaded implementation
> quite a lot. With 8 CPUs running, the resulting errors are in the
> range of 500 per vCPU (10 million iterations).
> Performance is another issue as mentioned before, but even more
> pronounced with 8 cores. Upstream QEMU needs around 10 seconds to
> complete, with multi-threading around 100 seconds for the same test.
>
> Best regards.
Hi,

I can reproduce the atomic errors with the test something is definitely 
wrong.
I know about the performance issue I fixed it in the patch-set I'll send.

Thanks,
Fred

      parent reply	other threads:[~2015-06-25 12:43 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-24 15:34 [Qemu-devel] [RFC PATCH] target-arm/psci.c: wake up sleeping CPUs (MTTCG) Alex Bennée
2015-06-24 16:01 ` Paolo Bonzini
2015-06-24 17:18   ` Alex Bennée
2015-06-24 17:23     ` Paolo Bonzini
2015-06-24 18:15       ` Alex Bennée
2015-06-24 19:12     ` Peter Maydell
2015-06-25 15:44       ` Andrew Jones
2015-06-26  7:06         ` Alex Bennée
2015-06-26  8:05           ` Andrew Jones
2015-06-24 23:55 ` Alexander Spyridakis
2015-06-25  6:27   ` Alex Bennée
2015-06-25 12:43   ` Frederic Konrad [this message]

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