On Mon, Nov 14, 2016 at 4:25 PM, Andrew Morton <a...@linux-foundation.org> wrote: > On Fri, 11 Nov 2016 20:21:41 -0800 Dan Williams <dan.j.willi...@intel.com> > wrote: > >> Mark dax vmas as not migratable to exclude them from task_numa_work(). >> This is especially relevant for device-dax which wants to ensure >> predictable access latency and not incur periodic faults. >> >> ... >> >> @@ -177,6 +178,9 @@ static inline bool vma_migratable(struct vm_area_struct >> *vma) >> if (vma->vm_flags & (VM_IO | VM_PFNMAP)) >> return false; >> >> + if (vma_is_dax(vma)) >> + return false; >> + >> #ifndef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION >> if (vma->vm_flags & VM_HUGETLB) >> return false; > > I don't think the reader could figure out why this code is here, so... this? > > --- > a/include/linux/mempolicy.h~mm-disable-numa-migration-faults-for-dax-vmas-fix > +++ a/include/linux/mempolicy.h > @@ -180,6 +180,10 @@ static inline bool vma_migratable(struct > if (vma->vm_flags & (VM_IO | VM_PFNMAP)) > return false; > > + /* > + * DAX device mappings require predictable access latency, so avoid > + * incurring periodic faults. > + */ > if (vma_is_dax(vma)) > return false; >
Yes, thanks for fixing it up.
