bc6ba80858
ARS is an operation that can take 10s to 100s of seconds to find media errors that should rarely be present. If the platform crashes due to media errors in persistent memory, the expectation is that the BIOS will report those known errors in a 'short' ARS request. A 'short' ARS request asks platform firmware to return an ARS payload with all known errors, but without issuing a 'long' scrub. At driver init a short request is issued to all PMEM ranges before registering regions. Then, in the background, a long ARS is scheduled for each region. The ARS implementation is simplified to centralize ARS completion work in the ars_complete() helper. The timeout is removed since there is no facility to cancel ARS, and this otherwise arranges for system init to never be blocked waiting for a 'long' ARS. The ars_state flags are used to coordinate ARS requests from driver init, ARS requests from userspace, and ARS requests in response to media error notifications. Given that there is no notification of ARS completion the implementation still needs to poll. It backs off exponentially to a maximum poll period of 30 minutes. Suggested-by: Toshi Kani <toshi.kani@hpe.com> Co-developed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.