On Wed, Nov 06, 2013 at 03:21:55PM +0200, Kirill A. Shutemov wrote: > On Wed, Nov 06, 2013 at 10:31:31AM +0100, Peter Zijlstra wrote: > > On Wed, Nov 06, 2013 at 01:13:11AM +0200, Kirill A. Shutemov wrote: > > > I would like to get rid of __ptlock_alloc()/__ptlock_free() too, but I > > > don't see a way within C: we need to know sizeof(spinlock_t) on > > > preprocessor stage. > > > > > > We can have a hack on kbuild level: write small helper program to find out > > > sizeof(spinlock_t) before start building and turn it into define. > > > But it's overkill from my POV. And cross-compilation will be a fun. > > > > Ah, I just remembered, we have such a thing! > > Great! > > > @@ -1354,7 +1356,7 @@ static inline bool ptlock_init(struct page *page) > > * slab code uses page->slab_cache and page->first_page (for tail > > * pages), which share storage with page->ptl. > > */ > > - VM_BUG_ON(page->ptl); > > + VM_BUG_ON(*(unsigned long *)&page->ptl); > > Huh? Why not direct cast to unsigned long? > > VM_BUG_ON((unsigned long)page->ptl); I tried, GCC didn't dig that. I think because spinlock_t is a composite type and you cannot cast that to a primitive type. -- 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>