MPOL_MF_LAZY was added by commit b24f53a0bea3 ("mm: mempolicy: Add MPOL_MF_LAZY"), then it was disabled by commit a720094ded8c ("mm: mempolicy: Hide MPOL_NOOP and MPOL_MF_LAZY from userspace for now") right away in 2012. So, it is never ever exported to userspace. And, it looks nobody is interested in revisiting it since it was disabled 7 years ago. So, it sounds pointless to still keep it around. Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Signed-off-by: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx> --- Hi folks, I'm not sure if you still would like to revisit it later. And, I may be not the first one to try to remvoe it. IMHO, it sounds pointless to still keep it around if nobody is interested in it. include/uapi/linux/mempolicy.h | 3 +-- mm/mempolicy.c | 13 ------------- 2 files changed, 1 insertion(+), 15 deletions(-) diff --git a/include/uapi/linux/mempolicy.h b/include/uapi/linux/mempolicy.h index 3354774..eb52a7a 100644 --- a/include/uapi/linux/mempolicy.h +++ b/include/uapi/linux/mempolicy.h @@ -45,8 +45,7 @@ enum { #define MPOL_MF_MOVE (1<<1) /* Move pages owned by this process to conform to policy */ #define MPOL_MF_MOVE_ALL (1<<2) /* Move every page to conform to policy */ -#define MPOL_MF_LAZY (1<<3) /* Modifies '_MOVE: lazy migrate on fault */ -#define MPOL_MF_INTERNAL (1<<4) /* Internal flags start here */ +#define MPOL_MF_INTERNAL (1<<3) /* Internal flags start here */ #define MPOL_MF_VALID (MPOL_MF_STRICT | \ MPOL_MF_MOVE | \ diff --git a/mm/mempolicy.c b/mm/mempolicy.c index af171cc..67886f4 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -593,15 +593,6 @@ static int queue_pages_test_walk(unsigned long start, unsigned long end, qp->prev = vma; - if (flags & MPOL_MF_LAZY) { - /* Similar to task_numa_work, skip inaccessible VMAs */ - if (!is_vm_hugetlb_page(vma) && - (vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)) && - !(vma->vm_flags & VM_MIXEDMAP)) - change_prot_numa(vma, start, endvma); - return 1; - } - /* queue pages from current vma */ if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) return 0; @@ -1181,9 +1172,6 @@ static long do_mbind(unsigned long start, unsigned long len, if (IS_ERR(new)) return PTR_ERR(new); - if (flags & MPOL_MF_LAZY) - new->flags |= MPOL_F_MOF; - /* * If we are using the default policy then operation * on discontinuous address spaces is okay after all @@ -1226,7 +1214,6 @@ static long do_mbind(unsigned long start, unsigned long len, int nr_failed = 0; if (!list_empty(&pagelist)) { - WARN_ON_ONCE(flags & MPOL_MF_LAZY); nr_failed = migrate_pages(&pagelist, new_page, NULL, start, MIGRATE_SYNC, MR_MEMPOLICY_MBIND); if (nr_failed) -- 1.8.3.1