On Fri, Aug 04, 2017 at 09:28:17AM +0800, Huang, Ying wrote: > Peter Zijlstra <pet...@infradead.org> writes: > [snip] > > diff --git a/include/linux/smp.h b/include/linux/smp.h > > index 68123c1fe549..8d817cb80a38 100644 > > --- a/include/linux/smp.h > > +++ b/include/linux/smp.h > > @@ -14,13 +14,16 @@ > > #include <linux/llist.h> > > > > typedef void (*smp_call_func_t)(void *info); > > -struct call_single_data { > > +struct __call_single_data { > > struct llist_node llist; > > smp_call_func_t func; > > void *info; > > unsigned int flags; > > }; > > > > +typedef struct __call_single_data call_single_data_t > > + __aligned(sizeof(struct __call_single_data)); > > + > > Another requirement of the alignment is that it should be the power of > 2. Otherwise, for example, if someone adds a field to struct, so that > the size becomes 40 on x86_64. The alignment should be 64 instead of > 40.
Yes I know. This generates a compiler error if sizeof() isn't a power of 2. That's similar to the BUILD_BUG_ON() you added.