lkml.org 
[lkml]   [2007]   [Jun]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [patch 2/3] MAP_NOZERO - implement sys_brk2()
On Wed, 27 Jun 2007, Hugh Dickins wrote:

> In honesty, I should add that I dislike and distrust Davide's
> MAP_NOZERO very much indeed! Would much rather leave my cpus
> spending a little time in clear_page(). A uid in struct page
> (though I'm sure we could find somewhere to tuck it away) -
> the horror, the horror! But I've so far failed to find a killer
> argument against it, and am hoping for someone else to do so.

Little time? Please, do not trust me. Start oprofile and run a kernel
build. Look, I'm not even talking about som micro benchmark explicitly
built to exploit the thing. A kernel build.
You will find clear_page to be the *1st* kernel entry after cc1 and as.
That is bad for two reasons. The time it spends in there, and the cache it
blows.



- Davide


-
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: 2007-06-27 20:17    [W:0.052 / U:1.240 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site