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=-14.4 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=no 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 29DDBC433DF for ; Fri, 9 Oct 2020 07:35:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B653122264 for ; Fri, 9 Oct 2020 07:35:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="vc+c/HnX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732072AbgJIHfQ (ORCPT ); Fri, 9 Oct 2020 03:35:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45634 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726326AbgJIHfQ (ORCPT ); Fri, 9 Oct 2020 03:35:16 -0400 Received: from mail-il1-x142.google.com (mail-il1-x142.google.com [IPv6:2607:f8b0:4864:20::142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 191B0C0613D2 for ; Fri, 9 Oct 2020 00:35:16 -0700 (PDT) Received: by mail-il1-x142.google.com with SMTP id t12so8359898ilh.3 for ; Fri, 09 Oct 2020 00:35:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=PaPXS9VT+lYpkpjJinLXWcnp4KLFdSw8VYN9MeahkOk=; b=vc+c/HnXsil9RCVjjRH9kMTQepASSQ3iP0pY8hU/I8Denk1MgicOEPNjc9X1jwlHf9 GGPPC1F85R4jWz97xQnXpDExNtbnnmXybB7nbhff3V6k/qTEg3X/l9pqiOGdFQPBHUcl u8557vYVFImOa4zwDH5x/zPwP41qQyuieR3pIvnHWR7SlrhkH+IGu3RMDm8aHb5jUoac MjGQgENRUPP+RntU8ToiC15h74xVhzsXHOdxqKm+A95VX1JtxsP32aHIOaSfdRF0cptg ciGCwO43SU1fTSleFXILP9IXgpXl0G2x4Uhfee5JA5o5RnRG+UxN3u/Iv6tyEFod1wu6 V0pg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=PaPXS9VT+lYpkpjJinLXWcnp4KLFdSw8VYN9MeahkOk=; b=TiQY2wyumDDfcDKPXIlN7wV/CXuiUVyNzZOUkvT0RBvEPvLCXhAlOsx+S9nN82xwJE luRholMquCR47TvL7zj8/VGw7eEY3ppMFg5umiuCmhz+g/+6SqCsOPrvjSuEnOqCdMdL eIAUfj5Gvpcm1du4x8XJwHB/AjRWNHwLni9szZPgcPoUVzExckUvyKhRhJ4+ULmrl4w1 ojnDXbZVFjJJLKS8MVHWyDzUm8y1EkR7a5xT1LjQiUhmhNaIj5Rf7prmfrn3T5qGinKt 2Z6waRluwPWenVliOqXy/awJO/MP6W5NGUXQHA582PhJB9LsIijQZq8UCKvR/jxbAV71 Pkaw== X-Gm-Message-State: AOAM532dH6t17khsC5Thkoppn8jlMmO4kqfAy6ni3PUP9ysYdU6yagxl c/EHSLEnClqJ01kiZTMr/iPjZLH3dGdHwBmHZNmXJmWhR6E= X-Google-Smtp-Source: ABdhPJxmjZ+oiv+GpfzJEVFzb0pp5bzDfk6DgO8MrORZeprLJDyfxcokgPHKT0kTK2QZP+5M0WwCbTuQiFlm2tkCTZY= X-Received: by 2002:a92:5e42:: with SMTP id s63mr9822939ilb.205.1602228915147; Fri, 09 Oct 2020 00:35:15 -0700 (PDT) MIME-Version: 1.0 References: <20201007165111.172419-1-eric.dumazet@gmail.com> <20201008171846.335b435a@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> In-Reply-To: <20201008171846.335b435a@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> From: Eric Dumazet Date: Fri, 9 Oct 2020 09:35:03 +0200 Message-ID: Subject: Re: [PATCH net-next] net/sched: get rid of qdisc->padded To: Jakub Kicinski Cc: Eric Dumazet , "David S . Miller" , netdev , Cong Wang , Allen Pais Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Fri, Oct 9, 2020 at 2:18 AM Jakub Kicinski wrote: > > On Wed, 7 Oct 2020 09:51:11 -0700 Eric Dumazet wrote: > > diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h > > index 6c762457122fd0091cb0f2bf41bda73babc4ac12..d8fd8676fc724110630904909f64d7789f3a4b47 100644 > > --- a/include/net/sch_generic.h > > +++ b/include/net/sch_generic.h > > @@ -91,7 +91,7 @@ struct Qdisc { > > struct net_rate_estimator __rcu *rate_est; > > struct gnet_stats_basic_cpu __percpu *cpu_bstats; > > struct gnet_stats_queue __percpu *cpu_qstats; > > - int padded; > > + int pad; > > refcount_t refcnt; > > > > /* > > Hi Eric! > > Why keep the pad field? the member to lines down is > __cacheline_aligned, so we shouldn't have to manually > push things out? > > struct gnet_stats_queue __percpu *cpu_qstats; > int pad; I usually prefer adding explicit fields to tell where the holes are, for future reuse. Not many developers are aware of pahole existence :/ I renamed it to pad, I could have used padding or something else.