From: Amit Shah <amit.shah@redhat.com>
To: Anthony Liguori <anthony@codemonkey.ws>
Cc: Marcelo Tosatti <mtosatti@redhat.com>,
qemu list <qemu-devel@nongnu.org>,
Juan Quintela <quintela@redhat.com>
Subject: [Qemu-devel] Re: [PATCH v6 18/18] virtio-serial-bus: wake up iothread upon guest read notification
Date: Wed, 28 Apr 2010 12:59:21 +0530 [thread overview]
Message-ID: <20100428072921.GT27314@amit-x200.redhat.com> (raw)
In-Reply-To: <4BD721C7.8010102@codemonkey.ws>
On (Tue) Apr 27 2010 [12:41:27], Anthony Liguori wrote:
> On 04/27/2010 07:34 AM, Amit Shah wrote:
>> From: Marcelo Tosatti<mtosatti@redhat.com>
>>
>> Wake up iothread when buffers are consumed.
>>
>> Signed-off-by: Marcelo Tosatti<mtosatti@redhat.com>
>> Signed-off-by: Amit Shah<amit.shah@redhat.com>
>>
>
> What's the race here? This looks very odd to me.
When the guest indicates it has added buffers to the vq, the iothread
can then start consuming them. Without this notification, the iothread
only polls for free buffers when it times out or gets woken up
otherwise.
Other virtio devices do it similarly as well.
Amit
next prev parent reply other threads:[~2010-04-28 13:23 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-27 12:33 [Qemu-devel] [PATCH v6 00/18] PULL: virtio-serial fixes Amit Shah
2010-04-27 12:33 ` [Qemu-devel] [PATCH v6 01/18] virtio-serial: save/load: Ensure target has enough ports Amit Shah
2010-04-27 12:33 ` [Qemu-devel] [PATCH v6 02/18] virtio-serial: save/load: Ensure nr_ports on src and dest are same Amit Shah
2010-04-27 12:33 ` [Qemu-devel] [PATCH v6 03/18] virtio-serial: save/load: Ensure we have hot-plugged ports instantiated Amit Shah
2010-04-27 12:33 ` [Qemu-devel] [PATCH v6 04/18] virtio-serial: save/load: Send target host connection status if different Amit Shah
2010-04-27 12:33 ` [Qemu-devel] [PATCH v6 05/18] virtio-serial: Use control messages to notify guest of new ports Amit Shah
2010-04-27 12:34 ` [Qemu-devel] [PATCH v6 06/18] virtio-serial: whitespace: match surrounding code Amit Shah
2010-04-27 12:34 ` [Qemu-devel] [PATCH v6 07/18] virtio-serial: Remove redundant check for 0-sized write request Amit Shah
2010-04-27 12:34 ` [Qemu-devel] [PATCH v6 08/18] virtio-serial: Update copyright year to 2010 Amit Shah
2010-04-27 12:34 ` [Qemu-devel] [PATCH v6 09/18] virtio-serial: Propagate errors in initialising ports / devices in guest Amit Shah
2010-04-27 12:34 ` [Qemu-devel] [PATCH v6 10/18] virtio-serial: Send out guest data to ports only if port is opened Amit Shah
2010-04-27 12:34 ` [Qemu-devel] [PATCH v6 11/18] iov: Introduce a new file for helpers around iovs, add iov_from_buf() Amit Shah
2010-04-27 12:34 ` [Qemu-devel] [PATCH v6 12/18] iov: Add iov_to_buf and iov_size helpers Amit Shah
2010-04-27 12:34 ` [Qemu-devel] [PATCH v6 13/18] virtio-serial: Handle scatter-gather buffers for control messages Amit Shah
2010-04-27 12:34 ` [Qemu-devel] [PATCH v6 14/18] virtio-serial: Handle scatter/gather input from the guest Amit Shah
2010-04-27 12:34 ` [Qemu-devel] [PATCH v6 15/18] virtio-serial: Apps should consume all data that guest sends out / Fix virtio api abuse Amit Shah
2010-04-27 12:34 ` [Qemu-devel] [PATCH v6 16/18] virtio-serial: Discard data that guest sends us when ports aren't connected Amit Shah
2010-04-27 12:34 ` [Qemu-devel] [PATCH v6 17/18] virtio-serial: Implement flow control for individual ports Amit Shah
2010-04-27 12:34 ` [Qemu-devel] [PATCH v6 18/18] virtio-serial-bus: wake up iothread upon guest read notification Amit Shah
2010-04-27 17:41 ` [Qemu-devel] " Anthony Liguori
2010-04-27 17:58 ` Marcelo Tosatti
2010-04-27 18:13 ` Anthony Liguori
2010-04-28 7:29 ` Amit Shah [this message]
2010-04-28 13:25 ` Anthony Liguori
2010-04-28 16:34 ` Amit Shah
2010-04-27 17:37 ` [Qemu-devel] Re: [PATCH v6 05/18] virtio-serial: Use control messages to notify guest of new ports Anthony Liguori
2010-04-28 4:27 ` Amit Shah
2010-04-28 13:26 ` Anthony Liguori
2010-04-28 17:54 ` [Qemu-devel] Re: [PATCH v6 01/18] virtio-serial: save/load: Ensure target has enough ports Anthony Liguori
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20100428072921.GT27314@amit-x200.redhat.com \
--to=amit.shah@redhat.com \
--cc=anthony@codemonkey.ws \
--cc=mtosatti@redhat.com \
--cc=qemu-devel@nongnu.org \
--cc=quintela@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).