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smp: don't use 16-bit words for atomic accesses 

Yes, it should work, but it's a bad idea.  Not only did ARM64 not have
the 16-bit access code (there's a separate patch to add it), it's just
not a good atomic type.  Some architectures fundamentally don't do
atomic accesses in them (alpha), and it's not like it saves any space
here anyway because of structure packing issues.

We normally should aim for flags to be "unsigned int" or "unsigned
long".  And if space is at a premium, use a single byte (although that
causes problems on alpha again).  There might be very special cases
where a 16-byte entity is really wanted, but this is not one of them.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Linus Torvalds 2015-04-20 09:08:49 -07:00
parent 09d51602cf
commit f4d03bd143
1 changed files with 1 additions and 1 deletions
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2
include/linux/smp.h
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@ -18,7 +18,7 @@ struct call_single_data {
struct llist_node llist; struct llist_node llist;
smp_call_func_t func; smp_call_func_t func;
void *info; void *info;
u16 flags; unsigned int flags;
}; };
/* total number of cpus in this system (may exceed NR_CPUS) */ /* total number of cpus in this system (may exceed NR_CPUS) */