On 12/14, Kirill A. Shutemov wrote: > > On Mon, Dec 14, 2015 at 07:02:25PM +0800, yalin wang wrote: > > change find_vma() to break ealier when found the adderss > > is not in any vma, don't need loop to search all vma. > > > > Signed-off-by: yalin wang <yalin.wang2010@xxxxxxxxx> > > --- > > mm/mmap.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/mm/mmap.c b/mm/mmap.c > > index b513f20..8294c9b 100644 > > --- a/mm/mmap.c > > +++ b/mm/mmap.c > > @@ -2064,6 +2064,9 @@ struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) > > vma = tmp; > > if (tmp->vm_start <= addr) > > break; > > + if (!tmp->vm_prev || tmp->vm_prev->vm_end <= addr) > > + break; > > + > > This 'break' would return 'tmp' as found vma. But this would be right? Not that I think this optimization makes sense, I simply do not know, but to me this change looks technically correct at first glance... But the changelog is wrong or I missed something. This change can stop the main loop earlier; if "tmp" is the first vma, or if the previous one is below the address. Or perhaps I just misread that "not in any vma" note in the changelog. No? Oleg. -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>