On Wed, 22 Feb 2012 20:35:34 +0800 Hillf Danton <dhillf@xxxxxxxxx> wrote: > When unmapping given VM range, we could bail out if a reference page is > supplied and it is unmapped, which is a minor optimization. > > Signed-off-by: Hillf Danton <dhillf@xxxxxxxxx> > --- > > --- a/mm/hugetlb.c Wed Feb 22 19:34:12 2012 > +++ b/mm/hugetlb.c Wed Feb 22 19:50:26 2012 > @@ -2280,6 +2280,9 @@ void __unmap_hugepage_range(struct vm_ar > if (pte_dirty(pte)) > set_page_dirty(page); > list_add(&page->lru, &page_list); > + > + if (page == ref_page) > + break; > } > spin_unlock(&mm->page_table_lock); > flush_tlb_range(vma, start, end); Perhaps add a little comment to this explaining what's going on? It would be sufficient to do if (ref_page) break; This is more efficient, and doesn't make people worry about whether this value of `page' is the same as the one which pte_page(huge_ptep_get()) earlier returned. Why do we evaluate `page' twice inside that loop anyway? And why do we check for huge_pte_none() twice? It looks all messed up. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>