On Tue, Jul 12, 2011 at 11:51 AM, Tirtha Ghosh <gtirtha@xxxxxxxxx> wrote: > Use a shared memory between user space and kernel space. > The same physical memory can be translated as user-space virtual address as > well as kernel space. > See more about mmap, io_remap_pfn_range etc. and you will get an idea. > The main advantage with this u can avoid copying data between two spaces but > disadvantage associated is u need to request a fixed memory chunk from > kernel for this purpose. > > Thanx for reply . Regarding mmap usage , As per LDD3 , page 423 : "Not every device lends itself to the mmap abstraction; it makes no sense, for instance, for serial ports and other stream-oriented devices." . why mmap is not useful for stream-oriented devices ? After all even for stream-oriented device (as in my case ) , we need to copy data from kernel buffer to user-space buffer , and if copy can be avoided via any mechanism , it will be much faster . Regards Amit Nagal _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
