On Tue, 3 Dec 2019 14:22:33 +0100 Thomas Hellström (VMware) <thomas_os@xxxxxxxxxxxx> wrote: > We currently only do COW and write-notify on the PTE level, so if the > huge_fault() handler returns VM_FAULT_FALLBACK on wp faults, > split the huge pages and page-table entries. Also do this for huge PUDs > if there is no huge_fault() handler and the vma is not anonymous, similar > to how it's done for PMDs. There is no description here of *why* we are making this change? > Note that fs/dax.c does the splitting in the huge_fault() handler, but as > huge_fault() is implemented by modules we need to consider whether to > export the splitting functions for use in the modules or whether to try > to keep calls in the core. Opt for the latter. A follow-up patch can > remove the dax.c split_huge_pmd() if needed.
