From patchwork Tue Jan 24 19:03:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Niklas Cassel X-Patchwork-Id: 646479 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 349E3C25B50 for ; Tue, 24 Jan 2023 19:05:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234562AbjAXTFr (ORCPT ); Tue, 24 Jan 2023 14:05:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42460 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234434AbjAXTFJ (ORCPT ); Tue, 24 Jan 2023 14:05:09 -0500 Received: from esa5.hgst.iphmx.com (esa5.hgst.iphmx.com [216.71.153.144]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2CFC34FCFD; Tue, 24 Jan 2023 11:04:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1674587052; x=1706123052; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=OOqiYKfmWDTAp+2e6ZBSGTgyOhzF068SxglszHxUP28=; b=DbQCLA43W7uZiC23d6ii0Y7/wfZEFnF7BqGYLNf2d+bH2euuRofTjk5X jKZU3QQQ8uIGMNCvW6S7+nLuhqbhDSyDN+drPlyA1tQ9NABFlUmCwn5ep kk3XrtG4PGtiGBxM3HtgTbL9xjeHamXqlfM99N9S/UouaC451nuUCtzy7 kkgWYF0Ufe8bA/z9wYO+yQzUuobCtzgoI1wGP1KqzMln1VqsSbSCRXjp1 JjrE3jBNV6uc1tLfIoOfT/XtBAa5G01qbQx7gCWJIQQ6AkC7lTdSLS1Jy AzPIGY+r/6rtNTFe6gEGbDuz2Dx91n47gBHgCiGiP4qH6HJB04svflogi w==; X-IronPort-AV: E=Sophos;i="5.97,243,1669046400"; d="scan'208";a="221472992" Received: from h199-255-45-15.hgst.com (HELO uls-op-cesaep02.wdc.com) ([199.255.45.15]) by ob1.hgst.iphmx.com with ESMTP; 25 Jan 2023 03:04:11 +0800 IronPort-SDR: xR9iu7IKWzhmLgsT9J72gZcikp0axPQQH4kDGrMikRIqGtT1T0O5eRoJU3ZtIYmd3kdp7b9he7 mBnCwOx2O+SdRhHfkOSBABpyTSTUVYUFNz/FHc6lQDvDi+2lRpE2qlK2lAtbOOym02l6oxIadO IX3tf+gSB3alA2IQq910UBprfGwL1QCd4npDy1nJtnuKUdvIoewn7aiIfC4V/IulMYM9qfVBI8 Kck0u6qPIRwSvb9bLXzdiB8NxDFc/spvEt0gbNEvZ6s2juWJrPQxJDCgIM4dW0XnhQ4umRU5fK Upc= Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep02.wdc.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 24 Jan 2023 10:16:00 -0800 IronPort-SDR: yvox5jcHKJanTm6+tqUTC5eJy6q85LJ2+66/Lv7Twnq4g5JuwnTiKLtmgSMQ/Ds14KgfO+x5kU NEEueRAcxYamWS3JJf/z10bawlgkHMmXRRzhgzdWwJHGSf+l7RekM813Zofc2XmigmgTT1401T TEm+/ivBrNW7GbIT5PKAZRMDZ0kkXea3bAOrYXGaROrG4wXxBKdQ2mbMJrA/OlVlSZukJQkcNr Ul4CbI9iSQ0vxJP+hrX50mRw/0HG2+upeh2YueMZQ6FUHF2TKDxVhpw0YPH7DRD+dwMhCSJt7n jU8= WDCIronportException: Internal Received: from unknown (HELO x1-carbon.lan) ([10.225.164.48]) by uls-op-cesaip02.wdc.com with ESMTP; 24 Jan 2023 11:04:09 -0800 From: Niklas Cassel To: linux-kernel@vger.kernel.org Cc: Christoph Hellwig , Hannes Reinecke , Damien Le Moal , linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org, linux-block@vger.kernel.org, Niklas Cassel Subject: [PATCH v3 18/18] Documentation: sysfs-block-device: document command duration limits Date: Tue, 24 Jan 2023 20:03:04 +0100 Message-Id: <20230124190308.127318-19-niklas.cassel@wdc.com> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230124190308.127318-1-niklas.cassel@wdc.com> References: <20230124190308.127318-1-niklas.cassel@wdc.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org From: Damien Le Moal Document ABI/testing/sysfs-block-device the sysfs attributes present under /sys/block/*/device/duration_limits for ATA and SCSI devices supporting the command duration limits feature. Signed-off-by: Damien Le Moal Signed-off-by: Niklas Cassel Reviewed-by: Hannes Reinecke --- Documentation/ABI/testing/sysfs-block-device | 150 +++++++++++++++++++ 1 file changed, 150 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-block-device b/Documentation/ABI/testing/sysfs-block-device index 7ac7b19b2f72..3a32c86942f5 100644 --- a/Documentation/ABI/testing/sysfs-block-device +++ b/Documentation/ABI/testing/sysfs-block-device @@ -95,3 +95,153 @@ Description: This file does not exist if the HBA driver does not implement support for the SATA NCQ priority feature, regardless of the device support for this feature. + + +What: /sys/block/*/device/duration_limits/enable +Date: Dec, 2022 +KernelVersion: v6.3 +Contact: linux-scsi@vger.kernel.org +Description: + (RW) For ATA and SCSI devices supporting the command duration + limits feature, write to the file to turn on or off the + feature. By default this feature is turned off. If the device + does not support the command duration limits feature, this + attribute does not exist (the directory + "/sys/block/\*/device/duration_limits" does not exist). + Writing "1" to this file enables the use of command duration + limits for read and write commands in the kernel and turns on + the feature on the device. Writing "0" disables the feature. + + +What: /sys/block/*/device/duration_limits/read/[1-7]/* +Date: Dec, 2022 +KernelVersion: v6.3 +Contact: linux-scsi@vger.kernel.org +Description: + (RO) For ATA and SCSI devices supporting the command duration + limits feature, this shows the set of 7 command duration limits + descriptors for read commands currently set on the device. For + each of the 7 descritors, the following read-only attributes + are present: + + - duration_guideline: specifies the preferred length of time + in microseconds for the completion of a command. + + - duration_guideline_policy: specifies the policy action + taken if the duration_guideline attribute specifies a + non-zero command duration guideline that the device is + unable to achieve for a command. + + Possible values are: + + - 0x0: The device will complete the command at the + earliest possible time consistent with the specified + command duration guideline. + + - 0x1: If the specified command duration guideline has not + been achieved and the command duration guideline policy + field is not in the seventh command duration limits + descriptor, then the device continues processing that + command using the command duration limits descriptor + that has the next higher number. + + - 0x2: The device will continue processing the command as + with no command duration limits descriptor being used. + + - 0xD: The device will complete the command and an IO + failure will be reported to the user with the ETIME + error code. + + - 0xF: Same as 0xD. + + - max_active_time: specifies an upper limit in microseconds + on the time that elapses from the time at which the device + initiates actions to access, transfer, or act upon the + specified data until the time the device returns status for + the command. + + - max_active_time_policy: specifies the policy action taken + if the time used to process a command exceeds a non-zero + time specified by the max_active_time attribute. + + Possible values are: + + - 0x0: The device will complete the command at the + earliest possible time (i.e, do nothing based on the max + time limit not being met). + + - 0xD: The device will complete the command and an IO + failure will be reported to the user with the ETIME + error code. + + - 0xE: Same as 0xD. + + - 0xF: Same as 0xD. + + - max_inactive_time: specifies an upper limit in microseconds + on the time that elapses from the time at which the device + receives the command until the time at which the device + initiates actions to access, transfer, or act upon the + specified data. + + - max_inactive_time_policy: specifies the policy action taken + if a non-zero max_inactive_time limit is not met. + + Possible values are: + + - 0x0: The device will complete the command at the + earliest possible time (i.e, do nothing based on the max + time limit not being met). + + - 0xD: The device will complete the command and an IO + failure will be reported to the user with the ETIME + error code. + + - 0xF: Same as 0xD. + + +What: /sys/block/*/device/duration_limits/read/page +Date: Dec, 2022 +KernelVersion: v6.3 +Contact: linux-scsi@vger.kernel.org +Description: + (RO) For ATA and SCSI devices supporting the command duration + limits feature, this shows the name of the device VPD page + specifying the set of 7 command duration limits descriptors for + read commands. Possible values are "T2A" and "T2B". + + +What: /sys/block/*/device/duration_limits/write/[1-7]/* +Date: Dec, 2022 +KernelVersion: v6.3 +Contact: linux-scsi@vger.kernel.org +Description: + (RO) For ATA and SCSI devices supporting the command duration + limits feature, this shows the set of 7 command duration limits + descriptors for write commands currently set on the device. For + each of the 7 descritors, the same set of read-only attributes + as for read commands is present. + + +What: /sys/block/*/device/duration_limits/write/page +Date: Dec, 2022 +KernelVersion: v6.3 +Contact: linux-scsi@vger.kernel.org +Description: + (RO) For ATA and SCSI devices supporting the command duration + limits feature, this shows the name of the device VPD page + specifying the set of 7 command duration limits descriptors for + write commands. Possible values are "T2A" and "T2B". + + +What: /sys/block/*/device/duration_limits/perf_vs_duration_guideline +Date: Dec, 2022 +KernelVersion: v6.3 +Contact: linux-scsi@vger.kernel.org +Description: + (RO) For ATA and SCSI devices supporting the command duration + limits feature, this specifies the maximum percentage increase + in average command completion times (reduction in IOPS) that + is allowed for the device to perform actions based on the + contents of the duration guideline field in every command + duration limit descriptor for both read and write commands.