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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 1EAE9C433DF for ; Mon, 17 Aug 2020 07:02:17 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D98D22072D for ; Mon, 17 Aug 2020 07:02:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="cxoMfQqy" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D98D22072D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:45682 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k7Z9s-0004AZ-3Q for qemu-devel@archiver.kernel.org; Mon, 17 Aug 2020 03:02:16 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49020) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k7Z97-0003lJ-SX for qemu-devel@nongnu.org; Mon, 17 Aug 2020 03:01:30 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:40005 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1k7Z95-0000hq-8S for qemu-devel@nongnu.org; Mon, 17 Aug 2020 03:01:29 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1597647685; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=dwa0oIlPecwy5d2DLISCjR+TTGbaD8RhwTZIoZS5RPc=; b=cxoMfQqyyWuSBQB8ZNKCGUyqsO8gRu82PhkeIffaT3Hud5udcLFSKvUZsPMT7X26oAjDOq bOGCtXsaDjJ7ibXsOyqT2wjk5fLKITmRCHPlW77y/S2ABJeo1+uPcx1nVTa+HPG4prQhoV egwrTgwPBIq/lZzO/3UBWd/jbms5Rbs= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-290-kfpOWL70M5Om9tAfvme8qg-1; Mon, 17 Aug 2020 03:01:23 -0400 X-MC-Unique: kfpOWL70M5Om9tAfvme8qg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B115C18551AB; Mon, 17 Aug 2020 07:01:22 +0000 (UTC) Received: from sirius.home.kraxel.org (ovpn-112-195.ams2.redhat.com [10.36.112.195]) by smtp.corp.redhat.com (Postfix) with ESMTP id E49C6709E1; Mon, 17 Aug 2020 07:01:17 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id EC2C41753B; Mon, 17 Aug 2020 09:01:16 +0200 (CEST) Date: Mon, 17 Aug 2020 09:01:16 +0200 From: Gerd Hoffmann To: Laszlo Ersek Subject: Re: [PATCH] hw: virtio-gpu: remove duplicated 'virtqueue_pop' Message-ID: <20200817070116.ox4du6d6jva6wico@sirius.home.kraxel.org> References: <20200813153614.39917-1-liq3ea@163.com> <47b9f12f-2874-1e1c-2fc1-7ea1a81cc401@redhat.com> MIME-Version: 1.0 In-Reply-To: <47b9f12f-2874-1e1c-2fc1-7ea1a81cc401@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kraxel@redhat.com X-Mimecast-Spam-Score: 0.002 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=205.139.110.61; envelope-from=kraxel@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/08/17 00:54:24 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -40 X-Spam_score: -4.1 X-Spam_bar: ---- X-Spam_report: (-4.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: liq3ea@gmail.com, Li Qiang , qemu-devel@nongnu.org, mst@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi, > - If the get_next() invocation is simple, then style (1) is perfectly fine. Fully agree. Duplicating a single line is perfectly fine if it is simple enough that you can hardly get it wrong. > - Style (2) is the worst of all. Yes, especially because the break is three lines not two due to qemu code style. > - If style (1) is not appropriate for whatever reason, then style (3) is frequently a good replacement. Style (3) is sometimes rejected by coding style documents though. Style (3) is not usable if is_valid() is a function-like macro that does not evaluate its argument exactly once. Frequently, is_valid() is simply open-coded with C operators (using extra parens), for example: > or more verbosely > > while ((cmd = virtqueue_pop(vq, sizeof(struct virtio_gpu_ctrl_command))) != > NULL) { Style 3 tends to generate long lines, which in turn need line breaks like this. Also many parens don't help making code more readable. So I'd prefer to just leave things as-is. take care, Gerd