From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: Re: [PATCH] net/hyperv: Fix the stop/wake queue mechanism Date: Fri, 9 Dec 2011 08:35:08 -0800 Message-ID: <20111209163508.GA19001@suse.de> References: <1322855785-22776-1-git-send-email-haiyangz@microsoft.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: KY Srinivasan , "davem@davemloft.net" , "linux-kernel@vger.kernel.org" , "netdev@vger.kernel.org" , "devel@linuxdriverproject.org" To: Haiyang Zhang Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Fri, Dec 09, 2011 at 04:00:59PM +0000, Haiyang Zhang wrote: > > -----Original Message----- > > From: Haiyang Zhang [mailto:haiyangz@microsoft.com] > > Sent: Friday, December 02, 2011 2:56 PM > > To: Haiyang Zhang; KY Srinivasan; davem@davemloft.net; gregkh@suse.de; > > linux-kernel@vger.kernel.org; netdev@vger.kernel.org; > > devel@linuxdriverproject.org > > Subject: [PATCH] net/hyperv: Fix the stop/wake queue mechanism > > > > The ring buffer is only used to pass meta data for outbound packets. The > > actual payload is accessed by DMA from the host. So the stop/wake queue > > mechanism based on counting and comparing number of pages sent v.s. > > number > > of pages in the ring buffer is wrong. Also, there is a race condition in > > the stop/wake queue calls, which can stop xmit queue forever. > > > > The new stop/wake queue mechanism is based on the actual bytes used by > > outbound packets in the ring buffer. The check for number of outstanding > > sends after stop queue prevents the race condition that can cause wake > > queue happening earlier than stop queue. > > > > Signed-off-by: Haiyang Zhang > > Signed-off-by: K. Y. Srinivasan > > Reported-by: Long Li > > --- > > drivers/net/hyperv/netvsc.c | 14 +++++++++++--- > > drivers/net/hyperv/netvsc_drv.c | 24 +----------------------- > > 2 files changed, 12 insertions(+), 26 deletions(-) > > Hi Greg, > > Since the netvsc haven't been merged into Dave's tree yet after out of staging, > could you consider this patch for your tree? It's in my "to-apply" queue already. thanks, greg k-h