On Thu, Sep 12, 2019 at 03:11:14PM -0600, Yu Zhao wrote: > On Thu, Sep 12, 2019 at 12:40:35PM +0300, Kirill A. Shutemov wrote: > > On Wed, Sep 11, 2019 at 08:31:08PM -0600, Yu Zhao wrote: > > > Mask of slub objects per page shouldn't be larger than what > > > page->objects can hold. > > > > > > It requires more than 2^15 objects to hit the problem, and I don't > > > think anybody would. It'd be nice to have the mask fixed, but not > > > really worth cc'ing the stable. > > > > > > Fixes: 50d5c41cd151 ("slub: Do not use frozen page flag but a bit in the page counters") > > > Signed-off-by: Yu Zhao <yuzhao@xxxxxxxxxx> > > > > I don't think the patch fixes anything. > > Technically it does. It makes no sense for a mask to have more bits > than the variable that holds the masked value. I had to look up the > commit history to find out why and go through the code to make sure > it doesn't actually cause any problem. > > My hope is that nobody else would have to go through the same trouble. Just put some comments then. -- Kirill A. Shutemov