On Thu, Apr 12, 2018 at 09:10:23AM -0500, Christopher Lameter wrote: > On Wed, 11 Apr 2018, Matthew Wilcox wrote: > > I don't see how that works ... can you explain a little more? > > c->freelist is NULL and thus ___slab_alloc (slowpath) is called. > ___slab_alloc populates c->freelist and gets the new object pointer. > > if debugging is on then c->freelist is set to NULL at the end of > ___slab_alloc because deactivate_slab() is called. > > Thus the next invocation of the fastpath will find that c->freelist is > NULL and go to the slowpath. ... _ah_. I hadn't figured out that c->page was always NULL in the debugging case too, so ___slab_alloc() always hits the 'new_slab' case. Thanks!
