[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [RFC PATCH 0/4] aio: Don't poll ioeventfd in nested aio
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [RFC PATCH 0/4] aio: Don't poll ioeventfd in nested aio_poll() |
Date: |
Thu, 28 May 2015 14:01:34 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 |
On 28/05/2015 13:49, Fam Zheng wrote:
> On Thu, 05/28 13:19, Paolo Bonzini wrote:
>>
>>
>> On 28/05/2015 13:16, Fam Zheng wrote:
>>>> On 28/05/2015 03:46, Fam Zheng wrote:
>>>>> The main context uses iohandler and aio_dispatch, neither calls
>>>>> aio_set_dispatching(). However, if we have [2], they can be changed to
>>>>> aio_poll(), then would this idea work?
>>>>
>>>> I think it's a bad idea to handle aio_poll for context B in a different
>>>> way, just because you have an outer aio_poll for context A...
>>>
>>> But we already do something similar: ignoring slirp, main_loop_wait() is
>>> like
>>> an iothread aio_poll() without the "outermost differentiation", while the
>>> current aio_poll() in bdrv_drain() is roughly "main_loop_wait() minus
>>> iohandlers".
>>
>> Right, but the two sets of iohandlers are stored in different places, so
>> it's obvious that you don't execute all of them. On the other hand,
>> examining global state in aio_poll is really bad.
>>
>
> OK.
>
> Would moving the ioeventfds to a new top level aio_loop_wait() be any better?
> That way no global state is needed.
If we need pause/resume anyway due to block/mirror.c's use of
block_job_defer_to_main_loop, I think this is not a problem anymore?
Paolo
- [Qemu-devel] [RFC PATCH 2/4] aio-win32: Implement aio_set_io_event_notifier, (continued)
- [Qemu-devel] [RFC PATCH 2/4] aio-win32: Implement aio_set_io_event_notifier, Fam Zheng, 2015/05/27
- [Qemu-devel] [RFC PATCH 3/4] virtio-blk: Use aio_set_io_event_notifier in dataplane, Fam Zheng, 2015/05/27
- [Qemu-devel] [RFC PATCH 4/4] virtio-scsi-dataplane: User aio_set_io_event_notifier, Fam Zheng, 2015/05/27
- Re: [Qemu-devel] [RFC PATCH 0/4] aio: Don't poll ioeventfd in nested aio_poll(), Paolo Bonzini, 2015/05/27
- Re: [Qemu-devel] [RFC PATCH 0/4] aio: Don't poll ioeventfd in nested aio_poll(), Fam Zheng, 2015/05/27
- Re: [Qemu-devel] [RFC PATCH 0/4] aio: Don't poll ioeventfd in nested aio_poll(), Paolo Bonzini, 2015/05/28
- Re: [Qemu-devel] [RFC PATCH 0/4] aio: Don't poll ioeventfd in nested aio_poll(), Fam Zheng, 2015/05/28
- Re: [Qemu-devel] [RFC PATCH 0/4] aio: Don't poll ioeventfd in nested aio_poll(), Paolo Bonzini, 2015/05/28
- Re: [Qemu-devel] [RFC PATCH 0/4] aio: Don't poll ioeventfd in nested aio_poll(), Fam Zheng, 2015/05/28
- Re: [Qemu-devel] [RFC PATCH 0/4] aio: Don't poll ioeventfd in nested aio_poll(),
Paolo Bonzini <=
- Re: [Qemu-devel] [RFC PATCH 0/4] aio: Don't poll ioeventfd in nested aio_poll(), Fam Zheng, 2015/05/28
- Re: [Qemu-devel] [RFC PATCH 0/4] aio: Don't poll ioeventfd in nested aio_poll(), Paolo Bonzini, 2015/05/28