From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 63192C43381 for ; Mon, 25 Mar 2019 15:49:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3D4622087E for ; Mon, 25 Mar 2019 15:49:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729477AbfCYPth (ORCPT ); Mon, 25 Mar 2019 11:49:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42836 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729368AbfCYPtg (ORCPT ); Mon, 25 Mar 2019 11:49:36 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D6365308A968; Mon, 25 Mar 2019 15:49:35 +0000 (UTC) Received: from carbon (ovpn-200-46.brq.redhat.com [10.40.200.46]) by smtp.corp.redhat.com (Postfix) with ESMTP id 203C7453D; Mon, 25 Mar 2019 15:49:30 +0000 (UTC) Date: Mon, 25 Mar 2019 16:49:29 +0100 From: Jesper Dangaard Brouer To: Eric Dumazet Cc: Felix Fietkau , netdev@vger.kernel.org, davem@davemloft.net, fw@strlen.de, pabeni@redhat.com, brouer@redhat.com Subject: Re: [PATCH v3] net: use bulk free in kfree_skb_list Message-ID: <20190325164929.03d67fb6@carbon> In-Reply-To: <5d973ed2-1915-a87d-d10f-6a0f68240ac0@gmail.com> References: <20190325091456.54285-1-nbd@nbd.name> <5d973ed2-1915-a87d-d10f-6a0f68240ac0@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.41]); Mon, 25 Mar 2019 15:49:36 +0000 (UTC) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, 25 Mar 2019 02:27:14 -0700 Eric Dumazet wrote: > > +#ifdef CONFIG_SLUB > > + /* SLUB writes into objects when freeing */ > > + prefetchw(segs); > > +#endif > > This is done too late : > You should probably either remove this prefetchw() > or do it before reading segs->next at the beginning of the loop. Agree. Not sure the prefetchw optimization makes sense here. IHMO just drop it in this patch. -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer