Re: [Linux-fbdev-devel] Re: Linux-fbdev-devel digest, Vol 1 #229 -

[James S. <jsi...@tr...>]

> > the graphics hardware. Locally we could use enhanced version of mmap, read
> > and write.
> 
> "enhanced version of mmap, read and write."   :^)

Yes. The only problem with kio buffers are they are hard drive specific so
they carry alot of extra weight. This is one of the main reasons kio
buffers haven't been used in the network layer yet. 
 
> unless read and write become special compiler macro type things, i still
> fail to see how any amount of enhancing done to read/write will approach
> buffer[offset].  

The whole point of kio buffers is to avoid a copy_[from/to]_user. You have
direct access to kernel memory space. This makes read/write as good if not
better than mmap. The only draw back is the offset issue with read/write.

Of course we have pread and pwrite to overcome this limitation.