On Wed, Aug 07, 2019 at 04:41:12PM +0800, Pingfan Liu wrote: > Clean up useless 'pfn' variable.
NAK there is a bug see below: > > Signed-off-by: Pingfan Liu <kernelf...@gmail.com> > Cc: "Jérôme Glisse" <jgli...@redhat.com> > Cc: Andrew Morton <a...@linux-foundation.org> > Cc: Mel Gorman <mgor...@techsingularity.net> > Cc: Jan Kara <j...@suse.cz> > Cc: "Kirill A. Shutemov" <kirill.shute...@linux.intel.com> > Cc: Michal Hocko <mho...@suse.com> > Cc: Mike Kravetz <mike.krav...@oracle.com> > Cc: Andrea Arcangeli <aarca...@redhat.com> > Cc: Matthew Wilcox <wi...@infradead.org> > To: linux...@kvack.org > Cc: linux-kernel@vger.kernel.org > --- > mm/migrate.c | 9 +++------ > 1 file changed, 3 insertions(+), 6 deletions(-) > > diff --git a/mm/migrate.c b/mm/migrate.c > index 8992741..d483a55 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -2225,17 +2225,15 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp, > pte_t pte; > > pte = *ptep; > - pfn = pte_pfn(pte); > > if (pte_none(pte)) { > mpfn = MIGRATE_PFN_MIGRATE; > migrate->cpages++; > - pfn = 0; > goto next; > } > > if (!pte_present(pte)) { > - mpfn = pfn = 0; > + mpfn = 0; > > /* > * Only care about unaddressable device page special > @@ -2252,10 +2250,10 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp, > if (is_write_device_private_entry(entry)) > mpfn |= MIGRATE_PFN_WRITE; > } else { > + pfn = pte_pfn(pte); > if (is_zero_pfn(pfn)) { > mpfn = MIGRATE_PFN_MIGRATE; > migrate->cpages++; > - pfn = 0; > goto next; > } > page = vm_normal_page(migrate->vma, addr, pte); > @@ -2265,10 +2263,9 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp, > > /* FIXME support THP */ > if (!page || !page->mapping || PageTransCompound(page)) { > - mpfn = pfn = 0; > + mpfn = 0; > goto next; > } > - pfn = page_to_pfn(page); You can not remove that one ! Otherwise it will break the device private case.