[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [RFC PATCH v2 00/49] Series short description
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [RFC PATCH v2 00/49] Series short description |
Date: |
Wed, 30 Jul 2014 11:25:12 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 |
Il 30/07/2014 09:44, Pavel Dovgaluk ha scritto:
>> From: Paolo Bonzini [mailto:address@hidden On Behalf Of Paolo Bonzini
>>>> - patch 16 should also use subsections, and perhaps apply to all other
>>>> CPUs too?
>>>
>>> We implemented replay only for i386 and ARM. If we'll change other
>>> targets, it will not
>>> add record/replay capabilities to them, but can confuse the reviewers.
>>
>> Why are these fields only required by record/replay?
>
> No, these fields can cause non-determinism for normal execution mode too.
> But these changes are not related to reverse execution. I can make patches
> for them
> and submit them separately, if needed.
Yes, thanks. If it causes nondeterminism for normal execution mode too,
it's better to apply them to all targets. If possible use a subsection,
though.
>>>> - patch 27 makes sense but VIRTUAL is used to skip blinking when the VM
>>>> is stopped
>>>
>>> Right, this is kind of hack. I haven't found better solution yet.
>>
>> I think it's okay to use REALTIME, just add runstate_is_running() to the
>> "if (now >= s->cursor_blink_time)".
>>
>> That said, "every read to virtual clock is written to the
>> replay log" worries me a bit from the point of view of thread-safety.
>> Do you need to log all reads because you don't use icount? Reads can
>> only happen at given points if you use icount, and you could simply log
>> the icount value at each synchronization point.
>
> We made two implementations of virtual clock. One uses host realtime clock
> and thus should be written into the log. Another one uses icount and
> calculated
> in one of the replay modules (similar to regular icount implementation).
> This patch series contains only first implementation, because it looks more
> convenient:
> user does not have to specify icount shift value, when starting the recording
> or replaying.
I think from the upstreaming point of view it's better to stick with
what makes the code simpler. Start by submitting only the icount-based
implementation, the other can come later.
Paolo
- [Qemu-devel] [RFC PATCH v2 38/49] replay: command line options, (continued)
- [Qemu-devel] [RFC PATCH v2 38/49] replay: command line options, Pavel Dovgalyuk, 2014/07/17
- [Qemu-devel] [RFC PATCH v2 20/49] block: add suffix parameter to bdrv_open functions, Pavel Dovgalyuk, 2014/07/17
- [Qemu-devel] [RFC PATCH v2 39/49] replay: snapshotting the virtual machine, Pavel Dovgalyuk, 2014/07/17
- [Qemu-devel] [RFC PATCH v2 13/49] pl031: add missed field to vmstate, Pavel Dovgalyuk, 2014/07/17
- [Qemu-devel] [RFC PATCH v2 18/49] migration: add vmstate for int8 and char arrays, Pavel Dovgalyuk, 2014/07/17
- Re: [Qemu-devel] [RFC PATCH v2 00/49] Series short description, Frederic Konrad, 2014/07/18
- Re: [Qemu-devel] [RFC PATCH v2 00/49] Series short description, Paolo Bonzini, 2014/07/24
- Re: [Qemu-devel] [RFC PATCH v2 00/49] Series short description, Pavel Dovgaluk, 2014/07/28
- Message not available
- Re: [Qemu-devel] [RFC PATCH v2 00/49] Series short description, Paolo Bonzini, 2014/07/28
- Re: [Qemu-devel] [RFC PATCH v2 00/49] Series short description, Pavel Dovgaluk, 2014/07/30
- Re: [Qemu-devel] [RFC PATCH v2 00/49] Series short description,
Paolo Bonzini <=
- Re: [Qemu-devel] [RFC PATCH v2 00/49] Series short description, Frederic Konrad, 2014/07/30
- Re: [Qemu-devel] [RFC PATCH v2 00/49] Series short description, Paolo Bonzini, 2014/07/30
- Re: [Qemu-devel] [RFC PATCH v2 00/49] Series short description, Frederic Konrad, 2014/07/30
- Re: [Qemu-devel] [RFC PATCH v2 00/49] Series short description, Frederic Konrad, 2014/07/31
- Re: [Qemu-devel] [RFC PATCH v2 00/49] Series short description, Paolo Bonzini, 2014/07/31
- Re: [Qemu-devel] [RFC PATCH v2 00/49] Series short description, Pavel Dovgaluk, 2014/07/31