Re: [PATCH] xt_log.h: don't use xchg() for simple assignment

["Jan Beulich" <JBeulich@suse.com>]

>>> On 23.03.12 at 11:07, Pablo Neira Ayuso <pablo@netfilter.org> wrote:
> On Thu, Mar 08, 2012 at 09:45:44AM +0000, Jan Beulich wrote:
>> At least on ia64 the (bogus) use of xchg() here results in the compiler
>> warning about an unused expression result. As only an assignment is
>> intended here, convert it to such.
>> 
>> Signed-off-by: Jan Beulich <jbeulich@suse.com>
>> 
>> ---
>>  include/net/netfilter/xt_log.h |    2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> --- 3.3-rc6/include/net/netfilter/xt_log.h
>> +++ 3.3-rc6-netfilter-xt_log-no-xchg/include/net/netfilter/xt_log.h
>> @@ -47,7 +47,7 @@ static void sb_close(struct sbuff *m)
>>  	if (likely(m != &emergency))
>>  		kfree(m);
>>  	else {
>> -		xchg(&emergency_ptr, m);
>> +		emergency_ptr = m;
> 
> That xchg is there for some reason. I think it's better if you just
> cast it to void.

If I knew the reason, I wouldn't mind doing so. But with no code
comment and nothing said in the corresponding commit message
I'm of the opinion that it is there just as a copy-and-paste result.

Jan