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From: Pranith Kumar <bobby.prani@gmail.com>
Date: Thu, 16 Oct 2014 12:01:23 -0400
Message-ID: <CAJhHMCBFQXzDhg8Ua7pM4uxtpGgydJsN-vy6cK3z2s6S0U=VyQ@mail.gmail.com>
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Subject: Re: [Qemu-devel] Counting barrier instructions in ARM
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To: Peter Maydell <peter.maydell@linaro.org>
Cc: QEMU Developers <qemu-devel@nongnu.org>

Hi Peter,

On Thu, Oct 16, 2014 at 4:05 AM, Peter Maydell <peter.maydell@linaro.org> wrote:
> On 16 October 2014 03:45, Pranith Kumar <bobby.prani@gmail.com> wrote:
>> The problem I am facing is that this seems to be crashing when run with a
>> multi-threaded executable.
>
> This is nothing to do with your changes -- user-mode QEMU does not
> support multi-threaded guest executables. QEMU may crash, hang,
> or stop with an assertion failure, fairly randomly. Don't try
> to run multithreaded guests :-)

OK, I will try to gather the statistics in system mode. Is there any
way to indicate from within the system to  qemu to start collecting the stats?

I dont want to collect the stats for bootup and other unrelated code paths.

>
>> Also the statistics gathered are not really accurate.
>
> This will be because you're using add rather than addi,
> so you're adding effectively a random number to the count
> every time (whatever TCG's "value in temporary 1" happens
> to be, I expect).

OK, I updated this when Max Filippov  pointed it out. Thanks!

-- 
Pranith