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=-6.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 0174FC3A59F for ; Mon, 19 Aug 2019 06:35:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CA2B520851 for ; Mon, 19 Aug 2019 06:35:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="BqWb4oAF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726663AbfHSGf0 (ORCPT ); Mon, 19 Aug 2019 02:35:26 -0400 Received: from mail-ot1-f65.google.com ([209.85.210.65]:35577 "EHLO mail-ot1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726261AbfHSGfZ (ORCPT ); Mon, 19 Aug 2019 02:35:25 -0400 Received: by mail-ot1-f65.google.com with SMTP id g17so685820otl.2; Sun, 18 Aug 2019 23:35:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=hehynR5oMc0ygrLfxgtV2LBMgj/0/3USx04Fi55/N18=; b=BqWb4oAF5EmHxqNMEkZ+gZT+JcDLLnz0XU9HRjN0B2I4FS/61qK4wt2ZtvUGFoei8g ZWJCaUh0TMbTF/cN6PII/9t1ebsCS77u8Og/uMeYojffXAQEsounkP6nhUaIiRxLsmTh WwSlnzyCl+uwRv/BwB106rGTgq8o/K3mK6mb1AWy0vSMGXwgGCId760ZnGSzJdnNdGnO QTBREfJ8UxrZoMdr1gnuodlCoatRC0qzAXP+VdfE20TZ4eYhNGt34Bm582mR52Uui35C 48W0uXhaUZF9Z4W4js/7DY6dYv6j7DuhZtGElAXTEBIUY52EbrhhKowuksR/iROLQnEL +sYw== 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=hehynR5oMc0ygrLfxgtV2LBMgj/0/3USx04Fi55/N18=; b=nFwFaHewk1Z5kohYViGfUirAE8iy7Y9Hq8yKWyjdxL1aYvB9nygR8gUPR1baKGDwWG vIQsC20OIGqOZDhAu1dpU5N6N8WeIB0sQqTTHWKizrY4NAjEUZDjZMq8FlgWuvSQpC2P CyXbOzcXH92GcZRe1RbxJJ9FnvoKHtsRsdUqmxFZsyu5f7PPwdEN+1rmQmjh5lc7rw9d kZYTuTTEaiW7AXx/Ql6dVOZFZjPK/UTMOlbGnyOwSaLfNVx0FPaNdT2uGfttakb9zbii XGq0Pd+yCWbD/SZQHmCXdh+89YrtNX68Ou6sGcMhARjEwNfP3/ra3r/zPuedfowC0kAV QjVg== X-Gm-Message-State: APjAAAUxxVoEwqwB0v1SB1519kMiWj4PwbeA6kpW0RxpIgIE0MpNnDJT uuLOE3xqTi6syVDnskHHEhwlGQFIEwtfrHTl46Q= X-Google-Smtp-Source: APXvYqzWetXyg+zssDPoektkY2F3mYhPVSAYE/uwaNM/FFoHYpl9cGOm5nWniMRcJ8f0c8s+tjYglzEdpvdjJ0iGUVE= X-Received: by 2002:a9d:5e19:: with SMTP id d25mr17527065oti.192.1566196524573; Sun, 18 Aug 2019 23:35:24 -0700 (PDT) MIME-Version: 1.0 References: <1565951171-14439-1-git-send-email-magnus.karlsson@intel.com> <2B143E7F-EE34-4298-B628-E2F669F89896@gmail.com> In-Reply-To: <2B143E7F-EE34-4298-B628-E2F669F89896@gmail.com> From: Magnus Karlsson Date: Mon, 19 Aug 2019 08:35:13 +0200 Message-ID: Subject: Re: [PATCH bpf-next] libbpf: remove zc variable as it is not used To: Jonathan Lemon , Maxim Mikityanskiy Cc: Yonghong Song , Magnus Karlsson , =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= , Alexei Starovoitov , Daniel Borkmann , Network Development , bpf Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sat, Aug 17, 2019 at 12:02 AM Jonathan Lemon wrote: > > > > On 16 Aug 2019, at 8:37, Yonghong Song wrote: > > > On 8/16/19 3:26 AM, Magnus Karlsson wrote: > >> The zc is not used in the xsk part of libbpf, so let us remove it. > >> Not > >> good to have dead code lying around. > >> > >> Signed-off-by: Magnus Karlsson > >> Reported-by: Yonghong Song > --- > >> tools/lib/bpf/xsk.c | 3 --- > >> 1 file changed, 3 deletions(-) > >> > >> diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c > >> index 680e630..9687da9 100644 > >> --- a/tools/lib/bpf/xsk.c > >> +++ b/tools/lib/bpf/xsk.c > >> @@ -65,7 +65,6 @@ struct xsk_socket { > >> int xsks_map_fd; > >> __u32 queue_id; > >> char ifname[IFNAMSIZ]; > >> - bool zc; > >> }; > >> > >> struct xsk_nl_info { > >> @@ -608,8 +607,6 @@ int xsk_socket__create(struct xsk_socket > >> **xsk_ptr, const char *ifname, > >> goto out_mmap_tx; > >> } > >> > >> - xsk->zc = opts.flags & XDP_OPTIONS_ZEROCOPY; > > > > Since opts.flags usage is removed. Do you think it makes sense to > > remove > > optlen = sizeof(opts); > > err = getsockopt(xsk->fd, SOL_XDP, XDP_OPTIONS, &opts, > > &optlen); > > if (err) { > > err = -errno; > > goto out_mmap_tx; > > } > > as well since nobody then uses opts? > > IIRC, this was added specifically in > 2761ed4b6e192820760d5ba913834b2ba05fd08c > so that userland code could know whether the socket was operating in > zero-copy > mode or not. Thanks for reminding me Jonathan. Roping in Maxim here since he wrote the patch. Was this something you planned on using but the functionality that needed it was removed? The patch set did go through a number of changes in the libbpf area, if I remember correctly. There are two options: either we remove it, or we add an interface in xsk.h so that people can use it. I vote for the latter since I think it could be useful. The sample app could use it at least :-). /Magnus > -- > Jonathan