virtualization.lists.linux-foundation.org archive mirror
 help / color / mirror / Atom feed
From: "Michael S. Tsirkin" <mst@redhat.com>
To: Qin Chuanyu <qinchuanyu@huawei.com>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	kvm@vger.kernel.org, virtualization@lists.linux-foundation.org
Subject: Re: [PATCH V2 5/6] vhost_net: poll vhost queue after marking DMA is done
Date: Wed, 12 Feb 2014 18:01:17 +0200	[thread overview]
Message-ID: <20140212160117.GA25440@redhat.com> (raw)
In-Reply-To: <52FB24EA.3060001@huawei.com>

On Wed, Feb 12, 2014 at 03:38:18PM +0800, Qin Chuanyu wrote:
> another question is that vhost_zerocopy_callback is called by kfree_skb,
> it may called in different thread context.
> vhost_poll_queue is called decided by ubufs->kref.refcount, this may
> cause there isn't any thread call  vhost_poll_queue, but at least
> one is needed. and this cause network break.
> We could repeat it by using 8 netperf thread in guest to xmit tcp to
> its host.

Thanks a lot for the report, will send the patch soon.

> 
> I think if using atomic_read to decide while do vhost_poll_queue or not,
> at least a spink_lock is needed.

No, nothing so drastic.

  parent reply	other threads:[~2014-02-12 16:01 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-30  4:29 [PATCH V2 0/6] vhost code cleanup and minor enhancement Jason Wang
2013-08-30  4:29 ` [PATCH V2 1/6] vhost_net: make vhost_zerocopy_signal_used() returns void Jason Wang
2013-09-02  5:51   ` Michael S. Tsirkin
2013-09-02  6:29     ` Jason Wang
2013-08-30  4:29 ` [PATCH V2 2/6] vhost_net: use vhost_add_used_and_signal_n() in vhost_zerocopy_signal_used() Jason Wang
2013-09-02  5:50   ` Michael S. Tsirkin
2013-09-02  6:28     ` Jason Wang
2013-08-30  4:29 ` [PATCH V2 3/6] vhost: switch to use vhost_add_used_n() Jason Wang
2013-08-30  4:29 ` [PATCH V2 4/6] vhost_net: determine whether or not to use zerocopy at one time Jason Wang
2013-08-30 18:35   ` Sergei Shtylyov
2013-09-02  3:15     ` Jason Wang
2013-08-30  4:29 ` [PATCH V2 5/6] vhost_net: poll vhost queue after marking DMA is done Jason Wang
2013-08-30 16:44   ` Ben Hutchings
2013-09-02  3:06     ` Jason Wang
2014-02-12  7:38   ` Qin Chuanyu
     [not found]   ` <52FB24EA.3060001@huawei.com>
2014-02-12 10:06     ` Jason Wang
2014-02-12 16:01     ` Michael S. Tsirkin [this message]
2013-08-30  4:29 ` [PATCH V2 6/6] vhost_net: correctly limit the max pending buffers Jason Wang
2013-09-02  5:56   ` Michael S. Tsirkin
2013-09-02  6:30     ` Jason Wang
2013-09-02  8:37       ` Jason Wang

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=20140212160117.GA25440@redhat.com \
    --to=mst@redhat.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=qinchuanyu@huawei.com \
    --cc=virtualization@lists.linux-foundation.org \
    /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).