Messages in this thread | | | Date | Wed, 6 Nov 2013 15:21:55 +0200 | From | "Kirill A. Shutemov" <> | Subject | Re: [PATCH] mm: create a separate slab for page->ptl allocation |
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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);
Otherwise:
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
-- Kirill A. Shutemov
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