lkml.org 
[lkml]   [2001]   [May]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [Question] Explanation of zero-copy networking
Alan Cox wrote:
> > so there's still single copy for write() of a mmap()ed page?
>
> An mmap page will go direct to disk.

Looking at the 2.4.4 code, mmap() of file followed by write() to socket
will copy the data once.

I could be mistaken (only glanced at the code quickly) but I base that
on the only call to ->sendpage being through sendfile.

So yes, there's a single copy overhead for mmap()+write().

-- Jamie
-
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: 2005-03-22 12:52    [from the cache]
©2003-2011 Jasper Spaans