How can I know arm kernel has suppored hardware float point? is there a kernel config to be enabled for this supporting? Lei On Wed, Jan 5, 2011 at 7:26 AM, julie Sullivan <kernelmail.jms@xxxxxxxxx> wrote: > >> I think the issue is the kernel is extremely concerned with the >> efficiency of the syscall path. >> >> Very legitimately some benchmarks just measure that one path to see >> how many thousands of syscalls per second can be made. >> >> To accelerate that path as much as possible, the linux kenel chooses >> not to incur the overhead of preserving the FP registers on every >> syscall. >> >> So kernel code that uses FP must first ensure any registers it uses >> are preserved. I don't recall ever writing any FP kernel code, so I >> don't know what facilities are available to do that. >> >> Greg > > Greg > > I had a vague idea about overhead being incurred due to the mode switch, but > your clear explanation makes it a lot easier to understand _where_ this > happens. > It's very helpful, thank you for your response. > > Julie > > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies@xxxxxxxxxxxxxxxxx > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > > _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
