From patchwork Wed Aug 11 03:36:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Damien Le Moal X-Patchwork-Id: 12429969 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=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 49B27C4338F for ; Wed, 11 Aug 2021 03:37:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2B65D60F22 for ; Wed, 11 Aug 2021 03:37:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233066AbhHKDhg (ORCPT ); Tue, 10 Aug 2021 23:37:36 -0400 Received: from esa6.hgst.iphmx.com ([216.71.154.45]:34652 "EHLO esa6.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233331AbhHKDha (ORCPT ); Tue, 10 Aug 2021 23:37:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1628653027; x=1660189027; h=from:to:subject:date:message-id:in-reply-to:references: mime-version:content-transfer-encoding; bh=tda/wI1ZwrYqH4umND8+Og63Ye/tFaSza1oypzr1bnw=; b=ZoXfBHZG5tim3Zuc62cMSqvo5BSxlb7Eutnxy+JqraBcXlnuyLO7zR9F BjHVcAx7i17ChIzTz5smGOsmdi1yWtRZKRguQO5AbfoUxY2/XV0TwMSwE eVHQLqrXw9Xsl6IZbc3h2SvgyyrI2JcjwdTbVuh70hlVrwG7wl7d/BWvR DUKMnAVuDcHWdOJi3lAhyI1ncpEP9Y1QFthgx6i0w2VLhfB9q5ial8w2f Tn3QBrvZhHV6oHLKF2q4/NeU6/SZU7BQ+PioIvvEb84aZpbJLM/KB7iNq bCV0ISEBM3823e2Ho07148t8ddHWurEPNDfrihYQlo6BU5X51xW4TRVeb A==; X-IronPort-AV: E=Sophos;i="5.84,311,1620662400"; d="scan'208";a="177454815" Received: from uls-op-cesaip01.wdc.com (HELO uls-op-cesaep01.wdc.com) ([199.255.45.14]) by ob1.hgst.iphmx.com with ESMTP; 11 Aug 2021 11:37:07 +0800 IronPort-SDR: HJeqTwh7r4Iq7C/NpQHtefspQmHCw9z5VxrwhPAQbcrUPzraXIg4x8rdQvf/JuErg3klyHNOP3 f5N32B2GOQ6axg8QDF3zJDJTolEUY/NfCc8zTDsvsDg9wE5HxntXdcdpxvDrmJxcsqQTbQHnq1 oxhytpKyE9gXO3eoEjUQhayv0rGqFxrT9GRpYtKM8rCUf7ASCelKGHcMkAWpsIlV8UCERW3JtS dPC6l28IBocEW1FWoa+8fTzOQArkNiIAsaISLMnPWhVE62qnpWmU5Rbd6eh+k+ZQNC+r7HZtS6 Ikque6d2f59VHKVdFfm9D5c5 Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep01.wdc.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Aug 2021 20:14:27 -0700 IronPort-SDR: FEZpBFus5K4fWMAEN+mHd0TgFuIveatp72Uyh2x27MEW0zq4qojs02FF9Dxp3k7YSsNwfmtUkb LiYzfuXUFhBfjFGA77x1/YdMOkmVf2QTq3DXgVTMr3u5g6Im2G5lGNZMxOxkAZQvydmmhJOxY3 cgbyqTsQTKluBApb9vli7rxpTAHQt4aLK0LEaFVlxn3o+6dpXxWkTqjlqx7dk1W/E+gNtFLwcS p9UY0rh+tKoLKXMAa9+IRCWk7+YVWTSQs9L1klQ4TzgGpkYCKz9g7QbcV2yurdj6ZWOW9icMNS GMo= WDCIronportException: Internal Received: from washi.fujisawa.hgst.com ([10.149.53.254]) by uls-op-cesaip02.wdc.com with ESMTP; 10 Aug 2021 20:37:06 -0700 From: Damien Le Moal To: Jens Axboe , linux-block@vger.kernel.org, Paolo Valente , linux-f2fs-devel@lists.sourceforge.net, Jaegeuk Kim , Chao Yu Subject: [PATCH v4 2/6] block: improve ioprio class description comment Date: Wed, 11 Aug 2021 12:36:58 +0900 Message-Id: <20210811033702.368488-3-damien.lemoal@wdc.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210811033702.368488-1-damien.lemoal@wdc.com> References: <20210811033702.368488-1-damien.lemoal@wdc.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org In include/usapi/linux/ioprio.h, change the ioprio class enum comment to remove the outdated reference to CFQ and mention BFQ and mq-deadline instead. Also document the high priority NCQ command use for RT class IOs directed at ATA drives that support NCQ priority. Signed-off-by: Damien Le Moal --- include/uapi/linux/ioprio.h | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/include/uapi/linux/ioprio.h b/include/uapi/linux/ioprio.h index 77b17e08b0da..6b735854aebd 100644 --- a/include/uapi/linux/ioprio.h +++ b/include/uapi/linux/ioprio.h @@ -13,10 +13,12 @@ #define IOPRIO_PRIO_VALUE(class, data) (((class) << IOPRIO_CLASS_SHIFT) | data) /* - * These are the io priority groups as implemented by CFQ. RT is the realtime - * class, it always gets premium service. BE is the best-effort scheduling - * class, the default for any process. IDLE is the idle scheduling class, it - * is only served when no one else is using the disk. + * These are the io priority groups as implemented by the BFQ and mq-deadline + * schedulers. RT is the realtime class, it always gets premium service. For + * ATA disks supporting NCQ IO priority, RT class IOs will be processed using + * high priority NCQ commands. BE is the best-effort scheduling class, the + * default for any process. IDLE is the idle scheduling class, it is only + * served when no one else is using the disk. */ enum { IOPRIO_CLASS_NONE,