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=-9.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MENTIONS_GIT_HOSTING,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 10FA6C433ED for ; Thu, 1 Apr 2021 16:15:14 +0000 (UTC) Received: by mail.kernel.org (Postfix) id D691461361; Thu, 1 Apr 2021 16:15:13 +0000 (UTC) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by mail.kernel.org (Postfix) with ESMTP id 4C0A961184; Thu, 1 Apr 2021 16:15:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4C0A961184 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=tempfail smtp.mailfrom=james.morse@arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 92FAE1570; Thu, 1 Apr 2021 09:15:12 -0700 (PDT) Received: from [192.168.0.14] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 57A0B3F792; Thu, 1 Apr 2021 09:15:11 -0700 (PDT) Subject: Re: [PATCH RFC] soc: fujitsu: Add cache driver code To: "tan.shaopeng@fujitsu.com" List-Id: Cc: 'Arnd Bergmann' , Will Deacon , Catalin Marinas , Olof Johansson , Linux ARM , SoC Team , "misono.tomohiro@fujitsu.com" References: <1614764303-34903-1-git-send-email-tan.shaopeng@jp.fujitsu.com> <1614764303-34903-2-git-send-email-tan.shaopeng@jp.fujitsu.com> <20210304104650.GA20843@willie-the-truck> From: James Morse Message-ID: Date: Thu, 1 Apr 2021 17:15:09 +0100 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Hi Tan Shaopeng, On 31/03/2021 09:52, tan.shaopeng@fujitsu.com wrote: >>> Given that all of this is outside of the scope of the architecture, I >>> don't think that arch/arm64/ is the right place for it. Perhaps this >>> would fit into the resctrl rework that James has been doing for MPAM? >> >> Indeed, that sounds like a good starting point. I don't understand enough about >> either of the two to be sure, but it sounds like there is some overlap in >> functionality, and ideally we would have one user interface that can deal with >> all the hardware implementations (intel, arm, fujitsu and any future ones). > According to my study, it seems possible to add A64FX's sector cache function > to resctrl. I think this depends on whether it maps to one of Intel RDT's existing schema. While adding new ones looks easy, it is bad for user-space as they are not portable between machines that support resctrl. > I heard you are working on resctrl rework for MPAM , > but I cannot find related patches on ML archive. Therefore, > I would like to know the status about MPAM support. Its about five or six series that refactor resctrl inside arch/x86 to have a clear boundary between arch-specific code and the resctrl code that implements the filesystem, then pull it out to /fs/ and build the MPAM driver to make it work for arm64. Unfortunately, its rather large (>100 patches), so will take some time to be reviewed. > (1) I think the first step is to support resctrl for ARM arch. > Have you finished the work of arm support and when will you release it? No-one wants a second copy of the code to implement resctrl, as this will introduce subtle bugs that user-space would have to work around, and make it harder to merge later. The first step is to refactor the arch/x86 implementation of resctrl so that the parts that are visible to user-space can be moved somewhere that is common to multiple architectures. I've posted the next chunk of that work here: https://lore.kernel.org/lkml/20210312175849.8327-1-james.morse@arm.com/ > (2) When will you release MPAM patch? The latest complete version of the tree is here: https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git/log/?h=mpam/snapshot/feb It is over a year old, and has plenty of bugs. I hope to push a newer version of the branch once I have a complete copy of the tree that has been tested, and is based on the current version of the ACPI table. Thanks, James 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=-10.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 9CB02C433B4 for ; Thu, 1 Apr 2021 16:31:40 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2AC0461386 for ; Thu, 1 Apr 2021 16:31:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2AC0461386 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:Cc:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=M+e8K0og1uO2PFZMCrr2JnbWJMzCtZuf7829dwrqWvc=; b=KLzHNMU5g43BPLGaF6W3/0WYW j1TE/Zkw91+jGJ8soEv0H4C2MHIQhQdBxGdolSQG+pAJ/6EIhuYXDo9vWkuykZwJwwaE2ChFShu3G VMXaLyR/d5etwPJp8nLUME4VK0QT74MfltzqEKrBUa8aoZLtmkFEymg6CPgwSwlVjX1ezsFhlasZe WJS8kd7ZEHzurKvYZGMAV6QLmrefVOU3x70+OB+yOmXdwlNZbqjEW8NAFrPOepIXmwMoyQmYUP7f7 rncHITvLbYd5GlkDH5zFHf1u+E2FKttlOtDSxo6Blf01v2aeCLT0G/40RtQpkuePVomVal02Qzp5J lfAEEbrcA==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lS0Cu-00AJFw-35; Thu, 01 Apr 2021 16:30:08 +0000 Received: from foss.arm.com ([217.140.110.172]) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lRzyV-00ADDY-9u for linux-arm-kernel@lists.infradead.org; Thu, 01 Apr 2021 16:15:30 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 92FAE1570; Thu, 1 Apr 2021 09:15:12 -0700 (PDT) Received: from [192.168.0.14] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 57A0B3F792; Thu, 1 Apr 2021 09:15:11 -0700 (PDT) Subject: Re: [PATCH RFC] soc: fujitsu: Add cache driver code To: "tan.shaopeng@fujitsu.com" List-Id: Cc: 'Arnd Bergmann' , Will Deacon , Catalin Marinas , Olof Johansson , Linux ARM , SoC Team , "misono.tomohiro@fujitsu.com" References: <1614764303-34903-1-git-send-email-tan.shaopeng@jp.fujitsu.com> <1614764303-34903-2-git-send-email-tan.shaopeng@jp.fujitsu.com> <20210304104650.GA20843@willie-the-truck> From: James Morse Message-ID: Date: Thu, 1 Apr 2021 17:15:09 +0100 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-GB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210401_171515_831730_4BF78856 X-CRM114-Status: GOOD ( 23.70 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Message-ID: <20210401161509.7_eGDgtSYJLITpaAUAPwfo0QjvvJfugF4mswCD3E4uk@z> Hi Tan Shaopeng, On 31/03/2021 09:52, tan.shaopeng@fujitsu.com wrote: >>> Given that all of this is outside of the scope of the architecture, I >>> don't think that arch/arm64/ is the right place for it. Perhaps this >>> would fit into the resctrl rework that James has been doing for MPAM? >> >> Indeed, that sounds like a good starting point. I don't understand enough about >> either of the two to be sure, but it sounds like there is some overlap in >> functionality, and ideally we would have one user interface that can deal with >> all the hardware implementations (intel, arm, fujitsu and any future ones). > According to my study, it seems possible to add A64FX's sector cache function > to resctrl. I think this depends on whether it maps to one of Intel RDT's existing schema. While adding new ones looks easy, it is bad for user-space as they are not portable between machines that support resctrl. > I heard you are working on resctrl rework for MPAM , > but I cannot find related patches on ML archive. Therefore, > I would like to know the status about MPAM support. Its about five or six series that refactor resctrl inside arch/x86 to have a clear boundary between arch-specific code and the resctrl code that implements the filesystem, then pull it out to /fs/ and build the MPAM driver to make it work for arm64. Unfortunately, its rather large (>100 patches), so will take some time to be reviewed. > (1) I think the first step is to support resctrl for ARM arch. > Have you finished the work of arm support and when will you release it? No-one wants a second copy of the code to implement resctrl, as this will introduce subtle bugs that user-space would have to work around, and make it harder to merge later. The first step is to refactor the arch/x86 implementation of resctrl so that the parts that are visible to user-space can be moved somewhere that is common to multiple architectures. I've posted the next chunk of that work here: https://lore.kernel.org/lkml/20210312175849.8327-1-james.morse@arm.com/ > (2) When will you release MPAM patch? The latest complete version of the tree is here: https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git/log/?h=mpam/snapshot/feb It is over a year old, and has plenty of bugs. I hope to push a newer version of the branch once I have a complete copy of the tree that has been tested, and is based on the current version of the ACPI table. Thanks, James _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel