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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id ACF4BCDB467 for ; Wed, 11 Oct 2023 16:36:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346913AbjJKQgF (ORCPT ); Wed, 11 Oct 2023 12:36:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44590 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235105AbjJKQgA (ORCPT ); Wed, 11 Oct 2023 12:36:00 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D2700B6; Wed, 11 Oct 2023 09:35:57 -0700 (PDT) Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.206]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4S5JGW5d5hz6JB4n; Thu, 12 Oct 2023 00:32:51 +0800 (CST) Received: from localhost (10.126.175.8) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Wed, 11 Oct 2023 17:35:54 +0100 Date: Wed, 11 Oct 2023 17:35:53 +0100 From: Jonathan Cameron To: "Sridharan, Vilas" CC: David Rientjes , Jiaqi Yan , "Luck, Tony" , "Grimm, Jon" , "dave.hansen@linux.intel.com" , "linuxarm@huawei.com" , "shiju.jose@huawei.com" , "linux-acpi@vger.kernel.org" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "rafael@kernel.org" , "lenb@kernel.org" , "naoya.horiguchi@nec.com" , "james.morse@arm.com" , "david@redhat.com" , "jthoughton@google.com" , "somasundaram.a@hpe.com" , "erdemaktas@google.com" , "pgonda@google.com" , "duenwen@google.com" , "mike.malvestuto@intel.com" , "gthelen@google.com" , "tanxiaofei@huawei.com" , "prime.zeng@hisilicon.com" Subject: Re: [RFC PATCH 2/9] memory: scrub: sysfs: Add Documentation entries for set of scrub attributes Message-ID: <20231011173553.00001b39@Huawei.com> In-Reply-To: References: <20230915172818.761-1-shiju.jose@huawei.com> <20230915172818.761-3-shiju.jose@huawei.com> <20230922111740.000046d7@huawei.com> <92f48c1c-3235-49b2-aabd-7da87ad3febc@google.com> <20231006140224.000018a2@Huawei.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.126.175.8] X-ClientProxiedBy: lhrpeml100001.china.huawei.com (7.191.160.183) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 6 Oct 2023 13:06:53 +0000 "Sridharan, Vilas" wrote: > [AMD Official Use Only - General] > > I do not believe AMD has implemented RASF/RAS2 at all. > > We are looking at it, but our initial impression is that it is insufficiently flexible for general use. (Not just for this feature, but for others in the future.) > > -Vilas Hi Vilas, So obvious question is - worth fixing? I'm not particularly keen to see 10+ different ways of meeting this requirement. Probably not too bad if that's 10+ drivers implementing the same userspace ABI, but definitely don't want 10 drivers and 10 ABIs. Jonathan > > -----Original Message----- > From: Jonathan Cameron > Sent: Friday, October 6, 2023 9:02 AM > To: David Rientjes > Cc: Jiaqi Yan ; Luck, Tony ; Grimm, Jon ; dave.hansen@linux.intel.com; Sridharan, Vilas ; linuxarm@huawei.com; shiju.jose@huawei.com; linux-acpi@vger.kernel.org; linux-mm@kvack.org; linux-kernel@vger.kernel.org; rafael@kernel.org; lenb@kernel.org; naoya.horiguchi@nec.com; james.morse@arm.com; david@redhat.com; jthoughton@google.com; somasundaram.a@hpe.com; erdemaktas@google.com; pgonda@google.com; duenwen@google.com; mike.malvestuto@intel.com; gthelen@google.com; tanxiaofei@huawei.com; prime.zeng@hisilicon.com > Subject: Re: [RFC PATCH 2/9] memory: scrub: sysfs: Add Documentation entries for set of scrub attributes > > Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding. > > > On Wed, 4 Oct 2023 20:18:12 -0700 (PDT) > David Rientjes wrote: > > > On Wed, 27 Sep 2023, Jiaqi Yan wrote: > > > > > > > 1. I am not aware of any chip/platform hardware that implemented > > > > > the hw ps part defined in ACPI RASF/RAS2 spec. So I am curious > > > > > what the RAS experts from different hardware vendors think about > > > > > this. For example, Tony and Dave from Intel, Jon and Vilas from > > > > > AMD. Is there any hardware platform (if allowed to disclose) > > > > > that implemented ACPI RASF/RAS2? If so, will vendors continue to > > > > > support the control of patrol scrubber using the ACPI spec? If > > > > > not (as Tony said in [1], will the vendor consider starting some future platform? > > > > > > > > > > If we are unlikely to get the vendor support, creating this ACPI > > > > > specific sysfs API (and the driver implementations) in Linux > > > > > seems to have limited meaning. > > > > > > > > There is a bit of a chicken and egg problem here. Until there is > > > > reasonable support in kernel (or it looks like there will be), > > > > BIOS teams push back on a requirement to add the tables. > > > > I'd encourage no one to bother with RASF - RAS2 is much less > > > > ambiguous. > > > > > > Here mainly to re-ping folks from Intel (Tony and Dave) and AMD > > > (Jon and Vilas) for your opinion on RAS2. > > > > > > > We'll need to know from vendors, ideally at minimum from both Intel > > and AMD, whether RAS2 is the long-term vision here. Nothing is set in > > stone, of course, but deciding whether RAS2 is the standard that we > > should be rallying around will help to guide future development > > including in the kernel. > > > > If RAS2 is insufficient for future use cases or we would need to > > support multiple implementations in the kernel for configuring the > > patrol scrubber depending on vendor, that's great feedback to have. > > > > I'd much rather focus on implementing something in the kernel that we > > have some clarity about the vendors supporting, especially when it > > comes with user visible interfaces, as opposed to something that may > > not be used long term. I think that's a fair ask and that vendor > > feedback is required here? > > Agreed and happy to have feedback from Intel and AMD + all the other CPU vendors who make use of ACPI + all the OEMs who add stuff well beyond what Intel and AMD tell them to :) I'll just note a lot of the ACPI support in the kernel covers stuff not used on mainstream x86 platforms because they are doing something custom and we didn't want 2 + X custom implementations... > > Some other interfaces for scrub control (beyond existing embedded ones) will surface in the next few months where RAS2 is not appropriate. > > Jonathan > >