On Mon, Feb 6, 2017 at 6:36 AM, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > On Fri, Feb 03, 2017 at 02:31:22PM -0700, Dave Jiang wrote: >> Since the introduction of FAULT_FLAG_SIZE to the vm_fault flag, it has >> been somewhat painful with getting the flags set and removed at the >> correct locations. More than one kernel oops was introduced due to >> difficulties of getting the placement correctly. Removing the flag >> values and introducing an input parameter to huge_fault that indicates >> the size of the page entry. This makes the code easier to trace and >> should avoid the issues we see with the fault flags where removal of the >> flag was necessary in the fallback paths. > > Why is this not in struct vm_fault? Because this is easier to read and harder to get wrong. Same arguments as getting rid of struct blk_dax_ctl. > Also can be use this opportunity > to fold ->huge_fault into ->fault? Hmm, yes, just need a scheme to not attempt huge_faults on pte-only handlers.
