From: Avi Kivity <avi@redhat.com>
To: Gleb Natapov <gleb@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>,
davidel@xmailserver.org, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH-RFC 2/2] eventfd: EFD_STATE flag
Date: Tue, 04 Aug 2009 12:25:49 +0300 [thread overview]
Message-ID: <4A77FE9D.3020505@redhat.com> (raw)
In-Reply-To: <20090804091755.GD4764@redhat.com>
On 08/04/2009 12:17 PM, Gleb Natapov wrote:
>> If a different read comes after the write but after our read, it will
>> have transferred the value, resulting in the same situation.
>>
>> I think reads should never block with a state based mechanism.
>>
>>
> Reader may want to poll for the status change.
>
Without epoll(), it's inherently racy since reads from other processes
can clear the status.
The "last read value" needs to be maintained for each reader, which is
not possible with read().
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2009-08-04 9:20 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1248803500.git.mst@redhat.com>
2009-07-28 17:54 ` [PATCH-RFC 1/2] eventfd: reorganize the code to simplify new flags Michael S. Tsirkin
2009-07-28 17:55 ` [PATCH-RFC 2/2] eventfd: EFD_STATE flag Michael S. Tsirkin
2009-08-03 15:09 ` Avi Kivity
2009-08-03 15:14 ` Michael S. Tsirkin
2009-08-03 15:29 ` Avi Kivity
2009-08-03 16:57 ` Michael S. Tsirkin
2009-08-04 8:53 ` Avi Kivity
2009-08-04 8:54 ` Michael S. Tsirkin
2009-08-04 9:17 ` Avi Kivity
2009-08-04 9:17 ` Gleb Natapov
2009-08-04 9:25 ` Avi Kivity [this message]
2009-08-04 9:23 ` Gleb Natapov
2009-08-04 9:30 ` Avi Kivity
2009-08-04 9:26 ` Michael S. Tsirkin
2009-08-04 10:06 ` Avi Kivity
2009-08-04 9:33 ` Michael S. Tsirkin
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