* [Qemu-devel] When AioHandler->is_external=true?
@ 2018-11-20 12:34 Dongli Zhang
2018-11-21 5:39 ` Fam Zheng
0 siblings, 1 reply; 2+ messages in thread
From: Dongli Zhang @ 2018-11-20 12:34 UTC (permalink / raw)
To: Qemu-block; +Cc: qemu-devel, famz
Hi,
Would you please help explain in which case AioHandler->is_external is true, and
when it is false?
I read about iothread and mainloop and I am little bit confused about it.
Thank you very much!
Dongli Zhang
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [Qemu-devel] When AioHandler->is_external=true?
2018-11-20 12:34 [Qemu-devel] When AioHandler->is_external=true? Dongli Zhang
@ 2018-11-21 5:39 ` Fam Zheng
0 siblings, 0 replies; 2+ messages in thread
From: Fam Zheng @ 2018-11-21 5:39 UTC (permalink / raw)
To: Dongli Zhang; +Cc: Qemu-block, qemu-devel
On Tue, 11/20 20:34, Dongli Zhang wrote:
> Hi,
>
> Would you please help explain in which case AioHandler->is_external is true, and
> when it is false?
>
> I read about iothread and mainloop and I am little bit confused about it.
VirtIO's ioeventfd is an example of is_external == true. It means the events
handler on this fd may initiate more I/O, such as read/write on virtual storage
backend, so are specially taken care of at certain points when we won't want
more I/O requests to be processed, such as when a block job is completing, or in
the middle of a QMP transaction.
Fam
^ permalink raw reply [flat|nested] 2+ messages in thread
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