From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f176.google.com (mail-pd0-f176.google.com [209.85.192.176]) by kanga.kvack.org (Postfix) with ESMTP id A82FC6B006E for ; Tue, 5 May 2015 19:28:54 -0400 (EDT) Received: by pdbqd1 with SMTP id qd1so212266767pdb.2 for ; Tue, 05 May 2015 16:28:54 -0700 (PDT) Received: from shards.monkeyblade.net (shards.monkeyblade.net. [2001:4f8:3:36:211:85ff:fe63:a549]) by mx.google.com with ESMTP id qk1si26507445pbb.80.2015.05.05.16.28.53 for ; Tue, 05 May 2015 16:28:53 -0700 (PDT) Date: Tue, 05 May 2015 19:28:51 -0400 (EDT) Message-Id: <20150505.192851.1294286421369630011.davem@davemloft.net> Subject: Re: [net-next PATCH 0/6] Add skb_free_frag to replace put_page(virt_to_head_page(ptr)) From: David Miller In-Reply-To: <20150504231000.1538.70520.stgit@ahduyck-vm-fedora22> References: <20150504231000.1538.70520.stgit@ahduyck-vm-fedora22> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: alexander.h.duyck@redhat.com Cc: linux-mm@kvack.org, netdev@vger.kernel.org, akpm@linux-foundation.org From: Alexander Duyck Date: Mon, 04 May 2015 16:14:42 -0700 > This patch set cleans up some of the handling of page frags used in the skb > allocation. The issue was we were having to use a number of calls to > virt_to_head_page in a number of places and then following that up with > put_page. Both calls end up being expensive, the first due to size, and > the second due to the fact that we end up having to call a number of other > functions before we finally see the page freed in the case of compound > pages. > > The skb_free_frag function is meant to resolve that by providing a > centralized location for the virt_to_head_page call and by coalesing > several checks such as the check for PageHead into a single check so that > we can keep the instruction cound minimal when freeing the page frag. > > With this change I am seeing an improvement of about 5% in a simple > receive/drop test. I'm going to need to see some buyin from the mm folks on this series. -- 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