On 9/20/23 11:53, Matthew Wilcox (Oracle) wrote:
> Even though we had successfully mapped the relevant page, we would
> rarely return success from filemap_map_folio_range(). That leads to
> falling back from the VMA lock path to the mmap_lock path, which is a
> speed & scalability issue. Found by inspection.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> Fixes: 617c28ecab22 ("filemap: batch PTE mappings")
> ---
Reviewed-by: Yin Fengwei <fengwei.yin@xxxxxxxxx>
Thanks a lot for taking care of this.
Regards
Yin, Fengwei
> mm/filemap.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/mm/filemap.c b/mm/filemap.c
> index 582f5317ff71..580d0b2b1a7c 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -3506,7 +3506,7 @@ static vm_fault_t filemap_map_folio_range(struct vm_fault *vmf,
> if (count) {
> set_pte_range(vmf, folio, page, count, addr);
> folio_ref_add(folio, count);
> - if (in_range(vmf->address, addr, count))
> + if (in_range(vmf->address, addr, count * PAGE_SIZE))
> ret = VM_FAULT_NOPAGE;
> }
>
> @@ -3520,7 +3520,7 @@ static vm_fault_t filemap_map_folio_range(struct vm_fault *vmf,
> if (count) {
> set_pte_range(vmf, folio, page, count, addr);
> folio_ref_add(folio, count);
> - if (in_range(vmf->address, addr, count))
> + if (in_range(vmf->address, addr, count * PAGE_SIZE))
> ret = VM_FAULT_NOPAGE;
> }
>
