Hi, On Fri, Jan 30, 2015 at 8:53 PM, Malte Vesper <malte.vesper@xxxxxxxxxxxxxxxxxxxxxxxxx> 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@xxxxxxxxx>: >>> 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. >> > > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies@xxxxxxxxxxxxxxxxx > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
