On Thu, Jan 24, 2019 at 10:13 PM Jane Chu <jane.chu@xxxxxxxxxx> wrote: > > Hi, Dave, > > While chatting with my colleague Erwin about the patchset, it occurred > that we're not clear about the error handling part. Specifically, > > 1. If an uncorrectable error is detected during a 'load' in the hot > plugged pmem region, how will the error be handled? will it be > handled like PMEM or DRAM? DRAM. > 2. If a poison is set, and is persistent, which entity should clear > the poison, and badblock(if applicable)? If it's user's responsibility, > does ndctl support the clearing in this mode? With persistent memory advertised via a static logical-to-physical storage/dax device mapping, once an error develops it destroys a physical *and* logical part of a device address space. That loss of logical address space makes error clearing a necessity. However, with the DRAM / "System RAM" error handling model, the OS can just offline the page and map a different one to repair the logical address space. So, no, ndctl will not have explicit enabling to clear volatile errors, the OS will just dynamically offline problematic pages.
