Hi Arun,
>On Thu, Jun 25, 2015 at 2:33 PM, Arun KS <getaru...@gmail.com> wrote: >Hello Mudongliang, > > > >On Tue, Jun 23, 2015 at 9:01 AM, 慕冬亮 <mudonglianga...@gmail.com> wrote: > >> > >> I know there are rarely float-point operations! What's the exception? > > In the linux kernel, how does it handle the float-point operations in > the >userland? > > >>Most of the userspace programs do not use FP instructions. So by > >>default floating point engine is turned off during a context switch. > >>When a process executes floating point instruction, an undefined > >>exception is generated. Exception handler enables the floating point > >>engine and jump back to the same instruction which caused the > >>exception so that it will get re executed with FP engine on. > > Is this somehow related to the platform in which linux runs? If the FP > operations are valid, then will that still generate the exception or it > does a context switch, turns on FP engine and re-executed? > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies@kernelnewbies.org > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >
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