From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrien Mazarguil Subject: Re: [PATCH] net/mlx5: fix Tx doorbell Date: Thu, 5 Jan 2017 19:12:12 +0100 Message-ID: <20170105181212.GR12822@6wind.com> References: <1481290078-4530-1-git-send-email-nelio.laranjeiro@6wind.com> <2da35386-f774-a1ca-c4f2-cc77f74f6e2c@intel.com> <20170105163226.GP12822@6wind.com> <20170105165223.GQ12822@6wind.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Nelio Laranjeiro , dev@dpdk.org To: Ferruh Yigit Return-path: Received: from mail-wm0-f48.google.com (mail-wm0-f48.google.com [74.125.82.48]) by dpdk.org (Postfix) with ESMTP id 6A7B82B91 for ; Thu, 5 Jan 2017 19:12:20 +0100 (CET) Received: by mail-wm0-f48.google.com with SMTP id a197so442004083wmd.0 for ; Thu, 05 Jan 2017 10:12:20 -0800 (PST) Content-Disposition: inline In-Reply-To: List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Thu, Jan 05, 2017 at 05:01:27PM +0000, Ferruh Yigit wrote: > On 1/5/2017 4:52 PM, Adrien Mazarguil wrote: > > On Thu, Jan 05, 2017 at 05:32:26PM +0100, Adrien Mazarguil wrote: > >> Hi Ferruh, > >> > >> On Thu, Jan 05, 2017 at 03:19:35PM +0000, Ferruh Yigit wrote: > >>> On 12/9/2016 1:27 PM, Nelio Laranjeiro wrote: > >>>> Too much data is uselessly written to the Tx doorbell. > >>>> > >>>> Fixes: 1d88ba171942 ("net/mlx5: refactor Tx data path") > >>>> > >>>> Signed-off-by: Nelio Laranjeiro > >>>> Acked-by: Adrien Mazarguil > >>>> > >>> > >>> Applied to dpdk-next-net/master, thanks. > >>> > >>> Is not CC'ing stable intentional, since this patch depends on a patch > >>> introduced in this release? If not intentional, please CC stable. > >> > >> I intended to update the commit message for this patch as in the meantime we > >> discovered it addresses a significant regression introduced in v16.11. > >> > >> CC'ing stable now. > >> > >> If possible, can you amend the commit log with: > >> > >> --- > >> > >> net/mlx5: fix Tx doorbell > >> > >> Too much data is uselessly written to the Tx doorbell, which since v16.11 > >> may also cause Tx queues to behave erratically and crash applications. > >> > >> This regression was seen on VF devices when the BlueFlame buffer size is > >> zero (txq->cqe_n == 0) due to the following change: > >> > >> - cqe = &(*txq->cqes)[ci & (txq->cqe_n - 1)].cqe64; > >> + cqe = &(*txq->cqes)[ci & ((1 << txq->cqe_n) - 1)]; > >> > >> Fixes: 1d88ba171942 ("net/mlx5: refactor Tx data path") > >> Fixes: e2f116ee3cac ("net/mlx5: reduce memory overhead for CQE handling") > >> > >> Signed-off-by: Nelio Laranjeiro > >> Acked-by: Adrien Mazarguil > >> Cc: stable@dpdk.org > >> > >> --- > > > > I mixed the commit that introduced the regression with a similar looking yet > > harmless one, here is the proper message to use, sorry for the noise: > > > > --- > > > > net/mlx5: fix Tx doorbell > > > > Too much data is uselessly written to the Tx doorbell, which since v16.11 > > may also cause Tx queues to behave erratically and crash applications. > > > > This regression was seen on VF devices when the BlueFlame buffer size is > > zero (txq->bf_buf_size) due to the following change: > > > > - txq->bf_offset ^= txq->bf_buf_size; > > + txq->bf_offset ^= (1 << txq->bf_buf_size); > > > > Fixes: 1d88ba171942 ("net/mlx5: refactor Tx data path") > > Fixes: d5793daefec8 ("net/mlx5: reduce memory overhead for BF handling") > > > > Signed-off-by: Nelio Laranjeiro > > Acked-by: Adrien Mazarguil > > Cc: stable@dpdk.org > > > > --- > > > > Can you please confirm commit in latest next-net? Not sure if the "Cc: stable@dpdk.org" line should have been kept, otherwise it's perfect, thanks Ferruh! -- Adrien Mazarguil 6WIND