On Fri, May 21, 2010 at 9:14 AM, Felipe Contreras <felipe.contre...@gmail.com> wrote: > On Fri, May 21, 2010 at 12:22 AM, Ohad Ben-Cohen <o...@wizery.com> wrote: >> On Wed, May 19, 2010 at 7:50 PM, Felipe Contreras >> <felipe.contre...@gmail.com> wrote: >>> I don't know what VM_IO means, but essentially we don't want to go >>> find each and page when we know the memory is contiguous. Although the >>> fact that the memory is writecombine would help us avoid unnecessary >>> flushes as well :) >> >> Yes, I guess you can remove those calls from the application :) > > Can't. From GStreamer point of view the decoder is independent of the > renderer, so we have no way to know that.
Can you please elaborate on this a little ? > Perhaps if the memory map > operation returned some information we can avoid those calls. I don't think it should; relying on the map call to tell us what type of buffer we just gave it smells like a bad interface. After all, it is the application who originally called mmap() to get access to that buffer, so it already knows if it's a framebuffer of not. Anyway it's not that an important optimization to do: the ioctl will just fail. The negative side is that the application will have no way to know if this is really a failure (did I just give a wrong buffer address to dspbridge ?) or not (oh it's the framebuffer, there's no mapping for that). Performance-wise, it's better than the previous implementation which would have executed redundant cache operation on the buffer. Thanks, Ohad. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
