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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 BD9F9C433DF for ; Mon, 6 Jul 2020 18:57:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E78A2065F for ; Mon, 6 Jul 2020 18:57:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729753AbgGFS5e (ORCPT ); Mon, 6 Jul 2020 14:57:34 -0400 Received: from mga14.intel.com ([192.55.52.115]:26885 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729569AbgGFS5e (ORCPT ); Mon, 6 Jul 2020 14:57:34 -0400 IronPort-SDR: 105EM1kqwYxoDWJshYhFTXr/A41btxnEadUfkV8JbsXAKzF4ZMDbZbdwGFqWseoN9c89lDMKLF 2I41llygswLw== X-IronPort-AV: E=McAfee;i="6000,8403,9674"; a="146555908" X-IronPort-AV: E=Sophos;i="5.75,320,1589266800"; d="scan'208";a="146555908" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Jul 2020 11:57:33 -0700 IronPort-SDR: SECpC06f7sleVuqjbYi+UhOG9+iSnjgs7OK+Salkc5hC6hqYL4Ic7TvxsQaYMCWcU8u6CShoGI 2P3FCU1ONBeA== X-IronPort-AV: E=Sophos;i="5.75,320,1589266800"; d="scan'208";a="456835188" Received: from tcramer-mobl.amr.corp.intel.com (HELO [10.255.2.114]) ([10.255.2.114]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Jul 2020 11:57:31 -0700 Subject: Re: [PATCH v3 6/6] dmaengine: idxd: add ABI documentation for shared wq To: Dave Jiang , vkoul@kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de Cc: Jing Lin , Tony Luck , Dan Williams , dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, ashok.raj@intel.com, fenghua.yu@intel.com References: <159405827797.19216.15283540319201919054.stgit@djiang5-desk3.ch.intel.com> <159405972142.19216.202541495863164149.stgit@djiang5-desk3.ch.intel.com> From: Dave Hansen Autocrypt: addr=dave.hansen@intel.com; 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Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <159405972142.19216.202541495863164149.stgit@djiang5-desk3.ch.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On 7/6/20 11:22 AM, Dave Jiang wrote: > +What: /sys/bus/dsa/devices/dsa/pasid_enabled > +Date: Jul 5, 2020 > +KernelVersion: 5.9.0 > +Contact: dmaengine@vger.kernel.org > +Description: To indicate if PASID (process address space identifier) is > + enabled or not for this device. > + > What: /sys/bus/dsa/devices/dsa/state > Date: Oct 25, 2019 > KernelVersion: 5.6.0 > @@ -116,6 +123,13 @@ Description: The maximum number of bandwidth tokens that may be in use at > one time by operations that access low bandwidth memory in the > device. > > +What: /sys/bus/dsa/devices/wq./block_on_fault > +Date: Jul 5, 2020 > +KernelVersion: 5.9.0 > +Contact: dmaengine@vger.kernel.org > +Description: To indicate block on fault is allowed or not for the work queue > + to support on demand paging. I'd also really appreciate some more "why" in addition to the "what" in the documentation. Why would a program or end user care that PASIDs are enabled or that on-demand paging is supported?