lkml.org 
[lkml]   [1998]   [Dec]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: PATCH: Raw device IO for 2.1.131

On Tue, 15 Dec 1998, David S. Miller wrote:

> Just one situation I want clarified, do you think we'll be able to fit
> into our framework a way to (for example) get at the user's
> application level headers during a write (ie. http header, then the
> data)?

i can see 3 solutions:

2) if we are lucky: ie. the headers are predictable (ipv6, video)
or the hardware plays well too, we can splice the data flow before
the DMA is done, thus we can feed both user-visible buffers and
'content' buffers. (or in the case of vide, where frame size
is predictable, the mapping can be static) This is not always
possible.

1) we are smart: we put some _simple_ dataflow-changing
functionality into the kernel. The ability to parse very simple
and secure headers. Push anything more complex to user-space: it's
going to cost time anyway, it's complex ...

(this functionality might be in the card as well...)

the problem is with the VM again: the VM has page-alignment and
granularity issues, making 'data-flow splice' harder.

-- mingo



-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:46    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site