On Fri, 2018-03-30 at 09:38 -0700, Dan Williams wrote: > On Fri, Mar 30, 2018 at 8:04 AM, Kani, Toshi <toshi.kani@xxxxxxx> 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 ��.n��������+%������w��{.n�����{�����ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f