spinlock variable protection

[Arun KS]

Hi,

On Fri, Jan 30, 2015 at 8:53 PM, Malte Vesper
<malte.vesper at postgrad.manchester.ac.uk> wrote:
> Spinlocks imply memory barriers as far as I am aware...
>
> Read here:
> http://lxr.free-electrons.com/source/Documentation/memory-barriers.txt#L1634

And may be here aswell,

http://lxr.free-electrons.com/source/Documentation/memory-barriers.txt#L1233

Thanks,
Arun
>
> On 30/01/15 14:20, Matwey V. Kornilov wrote:
>> 2015-01-30 16:52 GMT+03:00 buyitian <buyitian at gmail.com>:
>>> Please check the assembly code to double confirm the GCC behavior.
>>> Why will GCC change the order as what you mentioned? Only assembly code can tell you.
>> It does not change at the moment. I think it can change it.
>>
>> Because from line
>>    ret = hdl->count;
>> until line
>>    return ret;
>> there is no access to either ret or hdl->count. So it is reasonable to
>> optimizer to think that their values are the same and eliminate
>> unneeded variable.
>>
>
>
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