On 10/17/2017 01:48 PM, Huang, Ying wrote: > From: Huang Ying <[email protected]> > > Now, when the page table is walked in the implementation of > /proc/<pid>/pagemap, pmd_soft_dirty() is used for both the PMD huge > page map and the PMD migration entries. That is wrong, > pmd_swp_soft_dirty() should be used for the PMD migration entries > instead because the different page table entry flag is used.
Yeah, different flags can be used on various archs to represent mapped a PMD and a migration PMD entry. Sounds good. > > Cc: Michal Hocko <[email protected]> > Cc: "Kirill A. Shutemov" <[email protected]> > Cc: David Rientjes <[email protected]> > Cc: Arnd Bergmann <[email protected]> > Cc: Hugh Dickins <[email protected]> > Cc: "Jérôme Glisse" <[email protected]> > Cc: Daniel Colascione <[email protected]> > Cc: Zi Yan <[email protected]> > Cc: Naoya Horiguchi <[email protected]> > Signed-off-by: "Huang, Ying" <[email protected]> > --- > fs/proc/task_mmu.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c > index 2593a0c609d7..01aad772f8db 100644 > --- a/fs/proc/task_mmu.c > +++ b/fs/proc/task_mmu.c > @@ -1311,13 +1311,15 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned > long addr, unsigned long end, > pmd_t pmd = *pmdp; > struct page *page = NULL; > > - if ((vma->vm_flags & VM_SOFTDIRTY) || pmd_soft_dirty(pmd)) > + if (vma->vm_flags & VM_SOFTDIRTY) > flags |= PM_SOFT_DIRTY; > > if (pmd_present(pmd)) { > page = pmd_page(pmd); > > flags |= PM_PRESENT; > + if (pmd_soft_dirty(pmd)) > + flags |= PM_SOFT_DIRTY; > if (pm->show_pfn) > frame = pmd_pfn(pmd) + > ((addr & ~PMD_MASK) >> PAGE_SHIFT); > @@ -1329,6 +1331,8 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned long > addr, unsigned long end, > frame = swp_type(entry) | > (swp_offset(entry) << MAX_SWAPFILES_SHIFT); > flags |= PM_SWAP; > + if (pmd_swp_soft_dirty(pmd)) > + flags |= PM_SOFT_DIRTY; Though I was initially skeptical about whether this will compile on POWER because of lack of a pmd_swp_soft_dirty() definition but it turns out we have a generic one to fallback on as we dont define ARCH_ENABLE_THP_MIGRATION yet. #ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY #ifndef CONFIG_ARCH_ENABLE_THP_MIGRATION static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd) { return pmd; } static inline int pmd_swp_soft_dirty(pmd_t pmd) { return 0; } static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd) { return pmd; } #endif
