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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,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 2094AC433EF for ; Mon, 9 Sep 2019 12:17:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E6F80218AF for ; Mon, 9 Sep 2019 12:16:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="MblQ3f6q" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404860AbfIIMQ7 (ORCPT ); Mon, 9 Sep 2019 08:16:59 -0400 Received: from mail-lj1-f195.google.com ([209.85.208.195]:46828 "EHLO mail-lj1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404838AbfIIMQ6 (ORCPT ); Mon, 9 Sep 2019 08:16:58 -0400 Received: by mail-lj1-f195.google.com with SMTP id e17so12441778ljf.13 for ; Mon, 09 Sep 2019 05:16:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=cptlCQ347g/R/oxFT9VOf0f0wPB+y+T4B6Ay9zWG1MM=; b=MblQ3f6qW8Sm1i8qW5NiNRMcPRzExDnVXKJHg5yOSUTVndoGnT1tby42vpbVpfyE7G AQVWXL9lD++XGK8XR177xahdz2UHQDZofcLU/PUv3KhoVX+FuVrjchvCfR5RtY42uULZ 5LY0Hcx1yA0GCi2UxUZY1bRnkswW0rvRCClufMtWBl0o+iHVlJOhr5XJB8pVZTHYx40a wLbUHwey6zm7dpGAF+5SRgS7NOvff4uY1Hu0d1fDHfLYJ6pvF4jERFChMR2orzktwJUY xHlBQGYUZ1ZkQFgZSjkVYeKk9GAENJMZFcfE/SzFyZQPyTUbvu/JQgVJDlpJLJMLsBmF 0CUA== 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=cptlCQ347g/R/oxFT9VOf0f0wPB+y+T4B6Ay9zWG1MM=; b=bhT20Ad7K9jDl0bXLo63aLKvT8Bhqk3MxJ4YAraQfjIJf2QBlH37TEYRC+qo75KRHV B0yRFdZPp4aomgdaZFxyF/S2KG+vtmX+6qmAhVvZTLDW+0VoGc+yH6zxYCDpMuyBf/eR V10wiFMY0/jQQzYeCzv4zll6iJ4mxYDBIyVHzCTHoBcMvOCVgpifHftH4rTpX4W72x5A MtPXYjW1TcgxWxbWt2xSI75bgKdKbvV/998eG52O7Eq8/VEypgpadJV9ylV6lPqYvwrC dEMWtSfRnfSkjvPGLkfNIJBePfRL9x3rDvMIsqLcAgouyP+vC0XWK7ArdFsjy6Gr9eSJ 9mZg== X-Gm-Message-State: APjAAAWGTyOEGjodhxdGiWqMJC5KDpEKbsAVj17iupsc4DogREwaymTW J7hplKsKcaolpK74E1eBUAK8GEFjxdjMfsvRV4+0Qg== X-Google-Smtp-Source: APXvYqxD1HgwI3Ux3FuXQczreEPhWMnP1kFxwAJJ1OlX8aR2HqW3YVNGQT2/PewJjfBPRtyq5gXk7bMF6Sf+iQA1sgc= X-Received: by 2002:a2e:8091:: with SMTP id i17mr9692244ljg.13.1568031415705; Mon, 09 Sep 2019 05:16:55 -0700 (PDT) MIME-Version: 1.0 References: <14599f7165f23db2bf7b71a2596e808e2bc2056c.1567740135.git.baolin.wang@linaro.org> <3bcd69fd-2f8e-9b87-7292-4b0b1aa5be78@intel.com> In-Reply-To: <3bcd69fd-2f8e-9b87-7292-4b0b1aa5be78@intel.com> From: Baolin Wang Date: Mon, 9 Sep 2019 20:16:43 +0800 Message-ID: Subject: Re: [PATCH 2/4] mmc: Add virtual command queue support To: Adrian Hunter Cc: Ulf Hansson , riteshh@codeaurora.org, asutoshd@codeaurora.org, Orson Zhai , Chunyan Zhang , Arnd Bergmann , Linus Walleij , Vincent Guittot , linux-mmc , LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Adrian, On Mon, 9 Sep 2019 at 20:02, Adrian Hunter wrote: > > On 6/09/19 6:52 AM, Baolin Wang wrote: > > Now the MMC read/write stack will always wait for previous request is > > completed by mmc_blk_rw_wait(), before sending a new request to hardware, > > or queue a work to complete request, that will bring context switching > > overhead, especially for high I/O per second rates, to affect the IO > > performance. > > > > Thus this patch introduces virtual command queue interface, which is > > similar with the hardware command queue engine's idea, that can remove > > the context switching. > > CQHCI is a hardware interface for eMMC's that support command queuing. What > you are doing is a software issue queue, unrelated to CQHCI. I think you Yes. > should avoid all reference to CQHCI i.e. call it something else. Since its process is similar with CQHCI and re-use the CQHCI's interfaces, I called it virtual command queue. I am not sure what else name is better, any thoughts? VCQHCI? Thanks. -- Baolin Wang Best Regards