lkml.org 
[lkml]   [2005]   [Aug]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: zero-copy read() interface
On Thu, 18 August 2005 16:34:18 -0700, dean gaudet wrote:
> On Thu, 18 Aug 2005, Folkert van Heusden wrote:
>
> > Doesn't that one also use copying? I've also heard that using mmap is
> > expensive due to pagefaulting. I've found, for example, that copying a
> > 1.3GB file using read/write instead of mmap & memcpy is seconds faster.
>
> why would you memcpy if you're using mmap()? just write() the mmap()d
> region.

Still unnecessary. Userspace doesn't want to see the data at all, so
it shouldn't. The solution should either be sendfile(2), which Linus
doesn't like much, or the upcoming pipe stuff.

Jörn

--
Linux [...] existed just for discussion between people who wanted
to show off how geeky they were.
-- Rob Enderle
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-08-19 10:37    [from the cache]
©2003-2011 Jasper Spaans