From: Paolo Bonzini <pbonzini@redhat.com>
To: Catalin Vasile <catalinvasile92@gmail.com>, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] eventfd_signal()
Date: Fri, 08 May 2015 13:32:11 +0200 [thread overview]
Message-ID: <554C9EBB.6050600@redhat.com> (raw)
In-Reply-To: <554C9D0B.205@redhat.com>
On 08/05/2015 13:24, Paolo Bonzini wrote:
>
>
> On 08/05/2015 12:58, Catalin Vasile wrote:
>> Is eventfd blocking? By that I mean: If I signal the guest for
>> something, will that thread remain blocked till the guest clears the
>> interrupt?
>
> No. If you want that, write 2^64-2 to the eventfd and do a
>
> pfd.fd = ...
> pfd.events = POLLOUT;
> poll(&pfd, 1, -1);
>
> after the write.
>
> With this algorithm, a write will fail with EINVAL if there is already
> another pending write somewhere. The "poll" will still work after the
> failed write.
Oops, EAGAIN...
Paolo
prev parent reply other threads:[~2015-05-08 11:32 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-08 10:58 [Qemu-devel] eventfd_signal() Catalin Vasile
2015-05-08 11:24 ` Paolo Bonzini
2015-05-08 11:32 ` Paolo Bonzini [this message]
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