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=-2.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 B7686C433FE for ; Sat, 5 Dec 2020 14:20:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 77892230F9 for ; Sat, 5 Dec 2020 14:20:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726754AbgLEOTg (ORCPT ); Sat, 5 Dec 2020 09:19:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47022 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726366AbgLEM6x (ORCPT ); Sat, 5 Dec 2020 07:58:53 -0500 Received: from mail-io1-xd42.google.com (mail-io1-xd42.google.com [IPv6:2607:f8b0:4864:20::d42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB28DC09424E; Sat, 5 Dec 2020 04:47:11 -0800 (PST) Received: by mail-io1-xd42.google.com with SMTP id z5so8649901iob.11; Sat, 05 Dec 2020 04:47:11 -0800 (PST) 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:content-transfer-encoding; bh=/XpRQ3Q0ad+Q2MHPv+UdGhls3f1Aa2YKOEanYedPdIk=; b=egBmuZj9si4XcjX7hbuUrl90XqzQXy6ONSDPwnubdJFkNY/KxL8tQlLFtE6yQh+Q1z kiRIqpGw27Inc3+YPNWvfKxzE95d/O4RJ5dP/9jwZS4NLBZRXKZW82aAM2LjuwIoWzl+ uojW88o+rW24I544Gc6FgQXpFYf+XUSkWQKoXJRkFqefa5wN8J5CbNP9UItPiRXRCKtd LSiQ2OQN+T8V048oM7Y+eirAixi7/mXhQSCuUcb73tPmdhD8ll+vEokBfvVdgbDtf3hv 2Afswj2FDWL+iavY7+76Rj5Q5FcwRbt5fsXkw98m6vnmfWQ/vem9MofoRcIyJpM5NFX5 Vr6Q== 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:content-transfer-encoding; bh=/XpRQ3Q0ad+Q2MHPv+UdGhls3f1Aa2YKOEanYedPdIk=; b=uTIEiPgoTduBd4KvVi3A96LNRe05CftafIZsepJMKsWbL+BhJ2aJKqphYIbf/0vFu8 yi3W3KOb5eNaeaW0ZQzdFOhA5tN0785IMYFTV45m0L0lEfctOg5lz/71OZEnxIYSBo9r 4e+6Z8TmTSdU1Bba97gDR3zw8eKtp/nlDehuDwHq5RRpIAtn3Q2CWOGGRwGdPV/88PL0 QoLX476WVaptp9qgLGq8AqpuJxcVyukfrZA1QxXSjvlrpGmMksiF7rYeLKT84gpM4SLg a9O39rqgqLxjvN1GxmMVkMoaLD6X9B7OBSHKOEodNXJN2jtO17EJcZBFzxw0tXHgUQoZ b33g== X-Gm-Message-State: AOAM531p5UOdtS+hHejavH6zaN22NH202LPN115vsgpKnd30SS/jiQE/ 67pWFEb11THwp7JMcbowf1LgdLkirDMZsL72MAk= X-Google-Smtp-Source: ABdhPJybJZKeM2jBJZXvPwqinwg7SiIw9A482TPoAQbPUhShWdncpaKiViV/Yh0v1/8UU1YtvF3IUVI8LrUW6/uPJL0= X-Received: by 2002:a5d:8e06:: with SMTP id e6mr10819023iod.27.1607172431223; Sat, 05 Dec 2020 04:47:11 -0800 (PST) MIME-Version: 1.0 References: <1607063090-3426-1-git-send-email-minhquangbui99@gmail.com> <20201204161249.GA1141609@rowland.harvard.edu> In-Reply-To: <20201204161249.GA1141609@rowland.harvard.edu> From: =?UTF-8?Q?Minh_B=C3=B9i_Quang?= Date: Sat, 5 Dec 2020 19:47:01 +0700 Message-ID: Subject: Re: [PATCH] USB: dummy-hcd: Fix uninitialized array use in init() To: Alan Stern Cc: Felipe Balbi , Greg Kroah-Hartman , Corentin Labbe , Jules Irenge , Andrey Konovalov , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org V=C3=A0o Th 6, 4 thg 12, 2020 va=CC=80o lu=CC=81c 23:12 Alan Stern =C4=91=C3=A3 vi=E1=BA=BFt: > Does this initialization end up using less memory than an explicit > memset() call? You mean speed? In my opinion, there is no difference in speed between 2 wa= ys. When I compile this array initialization using gcc 5.4.0, this initialization becomes mov instructions when MAX_NUM_UDC=3D2 and becomes rep stos when MAX_NUM_UDC=3D32. I think it makes no difference when comparing with memset= () Thanks, Quang Minh