spinlock variable protection
Matwey V. Kornilov
matwey.kornilov at gmail.com
Fri Jan 30 10:29:37 EST 2015
Nice, thank you
30.01.2015 18:24 пользователь "Malte Vesper" <
malte.vesper at postgrad.manchester.ac.uk> написал:
> Spinlocks imply memory barriers as far as I am aware...
> Read here: http://lxr.free-electrons.com/source/Documentation/memory-
> 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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