From patchwork Thu Sep 9 02:35:44 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: 12482329 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=-16.5 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=unavailable 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 DAF5FC433FE for ; Thu, 9 Sep 2021 02:36:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C77096023D for ; Thu, 9 Sep 2021 02:36:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347815AbhIIChJ (ORCPT ); Wed, 8 Sep 2021 22:37:09 -0400 Received: from esa6.hgst.iphmx.com ([216.71.154.45]:42527 "EHLO esa6.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238723AbhIIChB (ORCPT ); Wed, 8 Sep 2021 22:37:01 -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=1631154952; x=1662690952; h=from:to:subject:date:message-id:in-reply-to:references: mime-version:content-transfer-encoding; bh=GzrETZRidFfNItPSNL+wFqWCgQ95fWYFF2GYt16RvEc=; b=AFZF0zPA1lD9CaRHFh75HUIQadKyxw4215iTVLIm3hMB47rK3TwGK72R /LqsvaIcqYd7AaKpX/jH6PUVIg2l1WgI4Y22bScJBfFy5pjUsAXUGIBOJ m7sxM4dLuhV3hyE0tVuffe1Kvuhl16nMx0uNWP3TP9+lWXjUg87k5N+yA wYbvfQQGsy5G+hddt1vww2UvLY4FI6Scnv97zncI3O+5Ta0gqNaRKzRIB hPUrplVxPcFFV0kviKXtlv3I9br0MDOOxnMJkUT4C11D/3C/9u6zICJHp PTo/MPzFKNIMmWws45mlk/kdUVYzisBWDOItKlJgmWJUA/wAvMV51kpzW Q==; X-IronPort-AV: E=Sophos;i="5.85,279,1624291200"; d="scan'208";a="180062216" Received: from h199-255-45-14.hgst.com (HELO uls-op-cesaep01.wdc.com) ([199.255.45.14]) by ob1.hgst.iphmx.com with ESMTP; 09 Sep 2021 10:35:52 +0800 IronPort-SDR: 1XKXK4zGeBJLzOfuSCd/thL1jHxgx8w6s7RIpmc77QJ5H0gpKrf7/V0kQ9rRDfEc0m3d4bNgwJ scsLev/LglG/ZoppqUMzHU7ZbnJPl/s56csd48VAMQXoYBjO0S7BoO0fjuXb+HISVg9wPMIdsf dauQqZ8ZIr2MNNAhPmiGN7/s79pCpD31+SBb3Nk/N5n8ko0IbIp8m0V6jZBV+XKA5IHWNslcrI CZRfPPkiUEZqcXIc8/h83QEqJFbo4iFkmcFMAvDLvHiFbpPvw6TiqjD50ozXk58rFqz5GJAHSq K9bfUvGXpabzOFzl+sndCp2W 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; 08 Sep 2021 19:12:27 -0700 IronPort-SDR: tN1KWA0S2mGa4HfJ8XCgr9akIGIt/PP/mv7Z76fEtA0hg2rE7wgLCSzHJDUQca0t98m4WgB4OP t5BI1QGmMuorXtZuP5pCTdooeBB66XjmO1vqHvs0U9gQ+fe+9YxU5zQR3BYDAwm6vMAsfU9TK6 qW6KgSmWzA/+YNetX7A9EO0tTOrlqoEuZ4w2SSl0NyCnG1mSfN08hGY3G9LJNQgLJGS4/YEkCe eH0AgTpLsoyiAcj1efSSWk4P7OIokr29rsguZFcNwXAkkD9MMMsSQIRqCUHeVG46Bf7clKAJec CfY= WDCIronportException: Internal Received: from washi.fujisawa.hgst.com ([10.149.53.254]) by uls-op-cesaip02.wdc.com with ESMTP; 08 Sep 2021 19:35:51 -0700 From: Damien Le Moal To: Jens Axboe , linux-block@vger.kernel.org, linux-ide@vger.kernel.org, "Martin K . Petersen" , linux-scsi@vger.kernel.org Subject: [PATCH v8 4/5] doc: document sysfs queue/independent_access_ranges attributes Date: Thu, 9 Sep 2021 11:35:44 +0900 Message-Id: <20210909023545.1101672-5-damien.lemoal@wdc.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210909023545.1101672-1-damien.lemoal@wdc.com> References: <20210909023545.1101672-1-damien.lemoal@wdc.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Update the file Documentation/block/queue-sysfs.rst to add a description of a device queue sysfs entries related to independent access ranges (e.g. concurrent positioning ranges for multi-actuator hard-disks). Signed-off-by: Damien Le Moal Reviewed-by: Hannes Reinecke --- Documentation/block/queue-sysfs.rst | 31 +++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/Documentation/block/queue-sysfs.rst b/Documentation/block/queue-sysfs.rst index 4dc7f0d499a8..b6e8983d8eda 100644 --- a/Documentation/block/queue-sysfs.rst +++ b/Documentation/block/queue-sysfs.rst @@ -286,4 +286,35 @@ sequential zones of zoned block devices (devices with a zoned attributed that reports "host-managed" or "host-aware"). This value is always 0 for regular block devices. +independent_access_ranges (RO) +------------------------------ + +The presence of this sub-directory of the /sys/block/xxx/queue/ directory +indicates that the device is capable of executing requests targeting +different sector ranges in parallel. For instance, single LUN multi-actuator +hard-disks will have an independent_access_ranges directory if the device +correctly advertizes the sector ranges of its actuators. + +The independent_access_ranges directory contains one directory per access +range, with each range described using the sector (RO) attribute file to +indicate the first sector of the range and the nr_sectors (RO) attribute file +to indicate the total number of sectors in the range starting from the first +sector of the range. For example, a dual-actuator hard-disk will have the +following independent_access_ranges entries.:: + + $ tree /sys/block//queue/independent_access_ranges/ + /sys/block//queue/independent_access_ranges/ + |-- 0 + | |-- nr_sectors + | `-- sector + `-- 1 + |-- nr_sectors + `-- sector + +The sector and nr_sectors attributes use 512B sector unit, regardless of +the actual block size of the device. Independent access ranges do not +overlap and include all sectors within the device capacity. The access +ranges are numbered in increasing order of the range start sector, +that is, the sector attribute of range 0 always has the value 0. + Jens Axboe , February 2009