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Date: Mon, 02 Feb 2015 09:31:34 +0100
From: Frederic Konrad <fred.konrad@greensocs.com>
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Subject: Re: [Qemu-devel] [RFC 01/10] target-arm: protect cpu_exclusive_*.
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To: Peter Maydell <peter.maydell@linaro.org>
Cc: mttcg@listserver.greensocs.com, "J. Kiszka" <jan.kiszka@siemens.com>, Mark Burton <mark.burton@greensocs.com>, QEMU Developers <qemu-devel@nongnu.org>, Alexander Graf <agraf@suse.de>, Paolo Bonzini <pbonzini@redhat.com>

On 29/01/2015 16:17, Peter Maydell wrote:
> On 16 January 2015 at 17:19,  <fred.konrad@greensocs.com> wrote:
>> From: KONRAD Frederic <fred.konrad@greensocs.com>
>>
>> This adds a lock to avoid multiple exclusive access at the same time in case of
>> TCG multithread.
>>
>> Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
Hi Peter,
> All the same comments I had on this patch earlier still apply:
>
>   * I think adding mutex handling code to all the target-*
>     frontends rather than providing facilities in common
>     code for them to use is the wrong approach
Ok we will fix that.
>   * You will fail to unlock the mutex if the ldrex or strex
>     takes a data abort
>   * This is making no attempt to learn from or unify with
>     the existing attempts at handling exclusives in linux-user.
>     When we've done this work we should have a single
>     mechanism for handling exclusives in a multithreaded
>     host environment which is used by both softmmu and useronly
>     configs
Can you point me to the existing attempts in linux-user?

Thanks,
Fred
>
> thanks
> -- PMM