| Message ID | 1565078411-27082-1-git-send-email-kernelfans@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/3] mm/migrate: clean up useless code in migrate_vma_collect_pmd() | expand |
This needs something beyond the subject line. Maybe ... After these assignments, we either restart the loop with a fresh variable, or we assign to the variable again without using the value we've assigned. Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> > goto next; > } > - pfn = page_to_pfn(page); After you've done all this, as far as I can tell, the 'pfn' variable is only used in one arm of the conditions, so it can be moved there. ie something like: - unsigned long mpfn, pfn; + unsigned long mpfn; ... - pfn = pte_pfn(pte); ... + unsigned long pfn = pte_pfn(pte); +
On Tue, Aug 06, 2019 at 06:35:03AM -0700, Matthew Wilcox wrote: > > This needs something beyond the subject line. Maybe ... > > After these assignments, we either restart the loop with a fresh variable, > or we assign to the variable again without using the value we've assigned. > > Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> > > > goto next; > > } > > - pfn = page_to_pfn(page); > > After you've done all this, as far as I can tell, the 'pfn' variable is > only used in one arm of the conditions, so it can be moved there. > > ie something like: > > - unsigned long mpfn, pfn; > + unsigned long mpfn; > ... > - pfn = pte_pfn(pte); > ... > + unsigned long pfn = pte_pfn(pte); > + > This makes code better. Thank you for the suggestion. Will send v2 for this patch. Regards, Pingfan
diff --git a/mm/migrate.c b/mm/migrate.c index 8992741..c2ec614 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -2230,7 +2230,6 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp, if (pte_none(pte)) { mpfn = MIGRATE_PFN_MIGRATE; migrate->cpages++; - pfn = 0; goto next; } @@ -2255,7 +2254,6 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp, 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); /* * By getting a reference on the page we pin it and that blocks
Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Jan Kara <jack@suse.cz> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org --- mm/migrate.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)