Re: [Qemu-devel] [PATCH v3 2/4] timer: protect timers_state's clock with seqlock

[liu ping fan]

On Tue, Aug 27, 2013 at 11:18 PM, Alex Bligh <address@hidden> wrote:
>
> On 27 Aug 2013, at 04:21, Liu Ping Fan wrote:
>
>> Note in tcg mode, vm_clock still read inside BQL, so icount is
>
> Should refer to QEMU_CLOCK_VIRTUAL if after my patches
>
Will change the log.
>> left without private lock's protection. As for cpu_ticks_* in
>> timers_state, it is still protected by BQL.
>
> I *think* what you are saying here is that after this patch,
> reading QEMU_CLOCK_VIRTUAL is threadsafe unless use_icount
> is true, in which case it is not thread safe as existing
> callers rely on the BQL.
>
Yes.
> The commit could be a bit more specific here, not least as
> if I read it right, that will need fixing before
> QEMU_CLOCK_VIRTUAL is used at all in other other threads.
>
Yes, this patch should be ready, before we use timers on other threads.

Thx,
Pingfan
> --
> Alex Bligh
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