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=-7.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,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 57141C433E2 for ; Wed, 16 Sep 2020 17:46:58 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 EA08B206B6 for ; Wed, 16 Sep 2020 17:46:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="GgiYeFRQ"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="B5ESeMEU" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EA08B206B6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-amlogic-bounces+linux-amlogic=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:To:Subject:Message-ID:Date:From:In-Reply-To: References:MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=DwXivvCW+K6yR/YYuXccHR6prkWgzqRk5T6ON88UffA=; b=GgiYeFRQ1G39VnyAc64hbwyQi RT+vNqYtvNic9cIduelFCeq7XXzT5lfnLYvUA/h7xAIMkBUwZEXvgu19a5i3+beFk1Rzqxs/0Zkx5 O1YBNStgEI9Eo4k4mwhtvcCGqoEs9sa6TRrTeHkMsRYeLWp8amiTQ0TZU/yKfgjqO0uXo32o66A9u 7+iO2BSfNyOQUHZhO1SSKhbWcRdOohk6frclH6C+IT8A1wZZ/YIOeDuzaOFeVfB9BVcWOviOwCmpg PO2WMikI2hMfGLz16CrOtJJInydCzdxVLTUw6fSfmDv3QijcousB1k5sxxgnGsREG8s8mW0yzQASn pKKrFCiUg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kIbW2-0004ps-In; Wed, 16 Sep 2020 17:46:46 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kIbW0-0004pH-21; Wed, 16 Sep 2020 17:46:44 +0000 Received: from mail-oi1-f176.google.com (mail-oi1-f176.google.com [209.85.167.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 270622074B; Wed, 16 Sep 2020 17:46:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600278403; bh=T7fAAdGMEwmTUz3pfaivZhFKXEL+DDksEtd73K/d1go=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=B5ESeMEUtj1Na7fmLooTO8GkHarnHss8zBYCfN/dmFbqoxSgiuinIyUxGXgDBiHRD wVyiSJIvR2essfm0M43MtG9+p1eZkTr/kBrVnLRsjPY6AVwDHkkeciV16Nwyt618Qi AQzbMGHh21c31NP/94SPiEy7qaTP3ohI6MHi7vzI= Received: by mail-oi1-f176.google.com with SMTP id c13so9060038oiy.6; Wed, 16 Sep 2020 10:46:43 -0700 (PDT) X-Gm-Message-State: AOAM531T6PVl6LIWRFrV9/Qv4/mLEat0WnD0qZ4PzHMTldqXtMDKje0x Bl/G0KZiGBRYYJ1dfK5LaAxOkuaQ2fYO2ftX/A== X-Google-Smtp-Source: ABdhPJzrTvS63xEc/YGj1M1VvkjQrHbt5CCRuhwhSuLfTUE5WrBgivzbCA7OeSqMGDgazvs3cRxd8meuptTx472enRI= X-Received: by 2002:aca:1711:: with SMTP id j17mr4051983oii.152.1600278402414; Wed, 16 Sep 2020 10:46:42 -0700 (PDT) MIME-Version: 1.0 References: <20200916170409.GA2543@kevin> In-Reply-To: <20200916170409.GA2543@kevin> From: Rob Herring Date: Wed, 16 Sep 2020 11:46:31 -0600 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 0/3] drm: panfrost: Coherency support To: Alyssa Rosenzweig X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200916_134644_317976_ABCC6D04 X-CRM114-Status: GOOD ( 13.20 ) X-BeenThere: linux-amlogic@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Tomeu Vizoso , Neil Armstrong , Robin Murphy , dri-devel , Steven Price , Linux IOMMU , Kevin Hilman , "open list:ARM/Amlogic Meson..." , Will Deacon , linux-arm-kernel , Jerome Brunet Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-amlogic" Errors-To: linux-amlogic-bounces+linux-amlogic=archiver.kernel.org@lists.infradead.org On Wed, Sep 16, 2020 at 11:04 AM Alyssa Rosenzweig wrote: > > > So I get a performance regression with the dma-coherent approach, even if it's > > clearly the cleaner. > > That's bizarre -- this should really be the faster of the two. Coherency may not be free. CortexA9 had something like 4x slower memcpy if SMP was enabled as an example. I don't know if there's anything going on like that specifically here. If there's never any CPU accesses mixed in with kmscube, then there would be no benefit to coherency. Rob _______________________________________________ linux-amlogic mailing list linux-amlogic@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-amlogic