Re: [PATCH v3] mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared

[Cyrill Gorcunov]

On Sun, Aug 24, 2014 at 10:59:24AM +0300, Kirill A. Shutemov wrote:
...
> > diff --git a/mm/mmap.c b/mm/mmap.c
> > index c1f2ea4..1b61fbc 100644
> > --- a/mm/mmap.c
> > +++ b/mm/mmap.c
> > @@ -1470,6 +1470,10 @@ int vma_wants_writenotify(struct vm_area_struct *vma)
> >  	if (vma->vm_ops && vma->vm_ops->page_mkwrite)
> >  		return 1;
> >  
> > +	/* Do we need to track softdirty? */
> > +	if (!(vm_flags & VM_SOFTDIRTY))
> 
> This will give false-positive if CONFIG_MEM_SOFT_DIRTY is disabled, since
> VM_SOFTDIRTY is 0 in this case:
> 
> 	if (IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) && !(vm_flags & VM_SOFTDIRTY))
> 
> Otherwise looks good to me.
> 
> Suggested-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>

Really sorry for delay. Thanks a huge, guys!

Reviewed-by: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/