From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f69.google.com (mail-pg0-f69.google.com [74.125.83.69]) by kanga.kvack.org (Postfix) with ESMTP id 47785681010 for ; Thu, 16 Feb 2017 14:03:59 -0500 (EST) Received: by mail-pg0-f69.google.com with SMTP id r207so32723254pgr.4 for ; Thu, 16 Feb 2017 11:03:59 -0800 (PST) Received: from shards.monkeyblade.net (shards.monkeyblade.net. [184.105.139.130]) by mx.google.com with ESMTP id y11si4615145plg.84.2017.02.16.11.03.58 for ; Thu, 16 Feb 2017 11:03:58 -0800 (PST) Date: Thu, 16 Feb 2017 14:03:55 -0500 (EST) Message-Id: <20170216.140355.2079700662225068523.davem@davemloft.net> Subject: Re: [PATCH v3 net-next 08/14] mlx4: use order-0 pages for RX From: David Miller In-Reply-To: References: <37bc04eb-71c9-0433-304d-87fcf8b06be3@mellanox.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: tom@herbertland.com Cc: tariqt@mellanox.com, edumazet@google.com, brouer@redhat.com, eric.dumazet@gmail.com, alexander.duyck@gmail.com, netdev@vger.kernel.org, kafai@fb.com, saeedm@mellanox.com, willemb@google.com, bblanco@plumgrid.com, ast@kernel.org, linux-mm@kvack.org From: Tom Herbert Date: Thu, 16 Feb 2017 09:05:26 -0800 > On Thu, Feb 16, 2017 at 5:08 AM, Tariq Toukan wrote: >> >> On 15/02/2017 6:57 PM, Eric Dumazet wrote: >>> >>> On Wed, Feb 15, 2017 at 8:42 AM, Tariq Toukan wrote: >>>> >>>> Isn't it the same principle in page_frag_alloc() ? >>>> It is called form __netdev_alloc_skb()/__napi_alloc_skb(). >>>> >>>> Why is it ok to have order-3 pages (PAGE_FRAG_CACHE_MAX_ORDER) there? >>> >>> This is not ok. >>> >>> This is a very well known problem, we already mentioned that here in the >>> past, >>> but at least core networking stack uses order-0 pages on PowerPC. >> >> You're right, we should have done this as well in mlx4 on PPC. >>> >>> mlx4 driver suffers from this problem 100% more than other drivers ;) >>> >>> One problem at a time Tariq. Right now, only mlx4 has this big problem >>> compared to other NIC. >> >> We _do_ agree that the series improves the driver's quality, stability, >> and performance in a fragmented system. >> >> But due to the late rc we're in, and the fact that we know what benchmarks >> our customers are going to run, we cannot Ack the series and get it >> as is inside kernel 4.11. >> > You're admitting that Eric's patches improve driver quality, > stability, and performance but you're not allowing this in the kernel > because "we know what benchmarks our customers are going to run". > Sorry, but that is a weak explanation. I have to agree with Tom and Eric. If your customers have gotten into the habit of using metrics which actually do not represent real life performance, that is a completely inappropriate reason to not include Eric's changes as-is. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org