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Date: Tue, 09 Oct 2012 14:01:28 +0200
From: Paolo Bonzini <pbonzini@redhat.com>
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Subject: Re: [Qemu-devel] Block I/O outside the QEMU global mutex was "Re:
 [RFC PATCH 00/17] Support for multiple "AIO contexts""
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To: Avi Kivity <avi@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>, Anthony Liguori <aliguori@us.ibm.com>, Ping Fan Liu <pingfank@linux.vnet.ibm.com>, Stefan Hajnoczi <stefanha@gmail.com>, qemu-devel@nongnu.org, Jan Kiszka <jan.kiszka@siemens.com>

Il 09/10/2012 13:55, Avi Kivity ha scritto:
> Oh, agree 100% raw + native aio wants to bypass coroutines/threads
> completely.

Even posix-aio-compat can bypass coroutines.

> We could perhaps even avoid refcounting, by shutting down the device
> thread as part of hotunplug.

Yes, you "just" join the thread, ask it to exit, and not hot-unplug
until it's done.

> [could we also avoid refcounting by doing the equivalent of
> stop_machine() during hotunplug?]

That's quite an interesting alternative.

Paolo