On Thu, Feb 04, 2021 at 09:50:32AM -0500, Peter Xu wrote: > We've got quite a few places (pte, pmd, pud) that explicitly checked against > whether we should break the cow right now during fork(). It's easier to > provide a helper, especially before we work the same thing on hugetlbfs. > > Since we'll reference is_cow_mapping() in mm.h, move it there too. Actually > it > suites mm.h more since internal.h is mm/ only, but mm.h is exported to the > whole kernel. With that we should expect another patch to use > is_cow_mapping() > whenever we can across the kernel since we do use it quite a lot but it's > always done with raw code against VM_* flags. > > Signed-off-by: Peter Xu <[email protected]> > include/linux/mm.h | 21 +++++++++++++++++++++ > mm/huge_memory.c | 8 ++------ > mm/internal.h | 5 ----- > mm/memory.c | 7 +------ > 4 files changed, 24 insertions(+), 17 deletions(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index ecdf8a8cd6ae..6ea20721d349 100644 > +++ b/include/linux/mm.h > @@ -1291,6 +1291,27 @@ static inline bool page_maybe_dma_pinned(struct page > *page) > GUP_PIN_COUNTING_BIAS; > } > > +static inline bool is_cow_mapping(vm_flags_t flags) > +{
It feels a bit more logical to pass in a struct vm_area_struct *' here? Jason
