From patchwork Wed Oct 27 02:22:22 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: 12586161 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 24E55C433FE for ; Wed, 27 Oct 2021 02:22:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0970C60F92 for ; Wed, 27 Oct 2021 02:22:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237849AbhJ0CZB (ORCPT ); Tue, 26 Oct 2021 22:25:01 -0400 Received: from esa5.hgst.iphmx.com ([216.71.153.144]:63769 "EHLO esa5.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238264AbhJ0CYy (ORCPT ); Tue, 26 Oct 2021 22:24:54 -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=1635301348; x=1666837348; h=from:to:subject:date:message-id:in-reply-to:references: mime-version:content-transfer-encoding; bh=Kpk9pmu0j/hTs2snhgUnLMJlmbZ5hcbx7kUm1MMB89Q=; b=ik89gXaE3nJ18pydBQLEK9kWVOoiyuKDUKMc7brsfGlpImJnJ1RIriBm y0c4sREm31VVvp+KIbaIbXfNMIvmK9kq6f6ciyae1N+NHZvQr4FRT3jKx D8vVbo3PPTNnxtqPIN7SoX6ECxDDuBQR02XbRqCfLMnkxKglO1gKd7Y3A G5MjdMSOFHbWYYOV5yvHPGenYYfLWrDHkfOXZzGz3ilAm+HwTQFjC4wu/ fyzlEI4p+SouC1X0XL7U5uFhj4xz9EIzkdyEkSRoBt8gmBGCeL92o6Kse byDxFbg477owzbMEVpRtlnSR8wF5x+LTnaO6OHZqQQWM0Aw1OR0qkVIBN Q==; X-IronPort-AV: E=Sophos;i="5.87,184,1631548800"; d="scan'208";a="183924740" Received: from uls-op-cesaip01.wdc.com (HELO uls-op-cesaep01.wdc.com) ([199.255.45.14]) by ob1.hgst.iphmx.com with ESMTP; 27 Oct 2021 10:22:28 +0800 IronPort-SDR: 0AfN1BdqzFgWMv8P/Jn39uXaufm2KAxVE1laloaj3bR1rTF1z4oVXRQbLcT5rDVbeCBCj3icqK 13clqXIJUblrmvpXN4beYXLPFWuEjwmKXZN3udhK2D5b11FIwNTl8HXUOjRIRmIS7B4/m84PJr JgO2ej+V8bpPbhnf3fIGZsR1cp/yZ8cmt9C4ckcvTVL3szLMqpbr42Qa8/hxzhaXQ2Kb6X2Y6C j1OrfC73SoInOgxPxzNqykS6YLrNC1RrpSn5yNSFmgTO006ELf1v6v/lajm2uVlUax8cNPcqKF pID6mU5OFUXf/CcW75ZVgEe5 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; 26 Oct 2021 18:57:58 -0700 IronPort-SDR: KlGmM717UANSG/dNDa0D3UI6gwkzsUvXXmXHWExEFvaCHOSCLWnJ7AlNnDwzN3bt/sithCSgrn qV/vBtGYTCVDjsYxh/7X3aVx9GCn9WMCzxbh/YWgDrc0WY5KBAsNhDOecUkIGPeNOxTTZ+gVjv Nxjps9lnLLqL9tYppeCSDVim2QDz8i4EhhOldbVDQ2oLz25F5ec/pUvtApY3X6+Yhla0BQgEQ0 TxquOGROhcMYtk2MxyCIWsZFjpG/kRdxFI43ZuEa89W6tr+BNyjOzt1AhHTu2J+1vu+DIC7F1a vlM= WDCIronportException: Internal Received: from washi.fujisawa.hgst.com ([10.149.53.254]) by uls-op-cesaip02.wdc.com with ESMTP; 26 Oct 2021 19:22:29 -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 v9 4/5] doc: document sysfs queue/independent_access_ranges attributes Date: Wed, 27 Oct 2021 11:22:22 +0900 Message-Id: <20211027022223.183838-5-damien.lemoal@wdc.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211027022223.183838-1-damien.lemoal@wdc.com> References: <20211027022223.183838-1-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 Reviewed-by: Martin K. Petersen Reviewed-by: Keith Busch --- 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