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Re: [Qemu-devel] [PATCH] target-arm: Use common CPU cycle infrastructure
From: |
Peter Maydell |
Subject: |
Re: [Qemu-devel] [PATCH] target-arm: Use common CPU cycle infrastructure |
Date: |
Mon, 5 Oct 2015 15:11:55 +0100 |
On 5 October 2015 at 15:09, Paolo Bonzini <address@hidden> wrote:
>
>
> On 03/10/2015 00:41, Peter Maydell wrote:
>> > What I meant to ask was, do you see any reason for cpu_get_ticks() to
>> > exist?
>> > If no architecture besides i386 wants to use it, perhaps the code should be
>> > moved there.
>>
>> OTOH various non-x86 things do use the closely related cpu_get_real_ticks(),
>> and the implementation of cpu_get_ticks() is very closely related to
>> the other clock code in cpus.c.
>
> cpu_get_real_ticks() is returning the host cycle counter;
> cpu_get_ticks() is stopping/resuming it when the VM is stopped/resumed.
> In other words, cpu_get_real_ticks() is to cpu_get_ticks() what
> QEMU_CLOCK_REALTIME is to QEMU_CLOCK_VIRTUAL.
...but it seems wrong to have anything in the simulation care
about the host cycle counter, especially since on some hosts
the underlying implementation is terrible.
thanks
-- PMM
- Re: [Qemu-devel] [PATCH] target-arm: Use common CPU cycle infrastructure, (continued)
- Re: [Qemu-devel] [PATCH] target-arm: Use common CPU cycle infrastructure, Christopher Covington, 2015/10/08
- Re: [Qemu-devel] [PATCH] target-arm: Use common CPU cycle infrastructure, Peter Maydell, 2015/10/08
- Re: [Qemu-devel] [PATCH] target-arm: Use common CPU cycle infrastructure, Christopher Covington, 2015/10/08
- Re: [Qemu-devel] [PATCH] target-arm: Use common CPU cycle infrastructure, Peter Crosthwaite, 2015/10/08
- Re: [Qemu-devel] [PATCH] target-arm: Use common CPU cycle infrastructure, Christopher Covington, 2015/10/08
- Re: [Qemu-devel] [PATCH] target-arm: Use common CPU cycle infrastructure, Peter Maydell, 2015/10/08
- Re: [Qemu-devel] [PATCH] target-arm: Use common CPU cycle infrastructure, Paolo Bonzini, 2015/10/08
- Re: [Qemu-devel] [PATCH] target-arm: Use common CPU cycle infrastructure,
Peter Maydell <=
- Re: [Qemu-devel] [PATCH] target-arm: Use common CPU cycle infrastructure, Paolo Bonzini, 2015/10/08
- Re: [Qemu-devel] [PATCH] target-arm: Use common CPU cycle infrastructure, Peter Maydell, 2015/10/08
- Re: [Qemu-devel] [PATCH] target-arm: Use common CPU cycle infrastructure, Paolo Bonzini, 2015/10/08
- Re: [Qemu-devel] [PATCH] target-arm: Use common CPU cycle infrastructure, Peter Maydell, 2015/10/08
- Re: [Qemu-devel] [PATCH] target-arm: Use common CPU cycle infrastructure, Paolo Bonzini, 2015/10/08