From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from g9t5009.houston.hpe.com (g9t5009.houston.hpe.com [15.241.48.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id BA42E224A9EBC for ; Fri, 30 Mar 2018 09:46:02 -0700 (PDT) From: "Kani, Toshi" Subject: Re: [PATCH 0/4] Adding support to parse BERT for libnvdimm Date: Fri, 30 Mar 2018 16:45:58 +0000 Message-ID: <1522428337.2693.271.camel@hpe.com> References: <152236282506.35558.2067249639136170490.stgit@djiang5-desk3.ch.intel.com> <1522422276.2693.268.camel@hpe.com> In-Reply-To: Content-Language: en-US Content-ID: <3EE1753F10861D4C873C13746E04B138@NAMPRD84.PROD.OUTLOOK.COM> MIME-Version: 1.0 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: "dan.j.williams@intel.com" Cc: "tony.luck@intel.com" , "linux-nvdimm@lists.01.org" , "rjw@rjwysocki.net" , "linux-acpi@vger.kernel.org" , "lenb@kernel.org" List-ID: On Fri, 2018-03-30 at 09:38 -0700, Dan Williams wrote: > On Fri, Mar 30, 2018 at 8:04 AM, Kani, Toshi wrote: > > On Thu, 2018-03-29 at 15:37 -0700, Dave Jiang wrote: > > > The following series implements support for parsing of the BERT records > > > and adding the error memory ranges to nvdimm badblocks in order for the > > > kernel to avoid prevent the kernel from accessing those areas. And with > > > the addition of this support, we can surface the nd regions instead of waiting > > > for ARS to complete. So the ARS handling is reworked to run in the > > > background and not block nd region registration. > > > > Hi Dave, > > > > I agree on the problem, and adding an ability to obtain pmem badblocks > > records at boot-time without waiting for a new ARS scan to complete is a > > good option for users. > > > > However, I do not think using the BERT table is a good approach. This > > requires FW to report pmem badblocks records with a new interface in > > addition to ARS records, which FW already implements for pmem. ACPI 6.2 > > defines Start ARS with Flags Bit[1] set to report badblocks record > > without starting a new ARS scan. We set this bit after receiving a 0x81 > > notification at this point. > > > > Can we use ARS with Flags bit[1] set at boot-time so that both OS and FW > > can use the same ARS implementation? > > You have a point. > > The other benefit I see to this policy is that it hopefully convinces > BIOS implementations to not run ARS at boot and leave it to the OS to > manage it in the background. If the platform has any critical errors > to report, i.e. ones that triggered a system reset, then it should be > able to report them in the flag-bit1 case. Agreed. > This also lets the implementation be completely self contained to the > nfit driver, and not grow any BERT entanglements that may or may not > be valid for the persistent memory case. Right. Thanks Dan! -Toshi _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm