lkml.org 
[lkml]   [2002]   [Sep]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: LMbench2.0 results
Hugh Dickins wrote:
>
> On Sun, 8 Sep 2002, Andrew Morton wrote:
> >
> > We need to find some way of making vm_enough_memory not call get_page_state
> > so often. One way of doing that might be to make get_page_state dump
> > its latest result into a global copy, and make vm_enough_memory()
> > only get_page_state once per N invokations. A speed/accuracy tradeoff there.
>
> Accuracy is not very important in that sysctl_overcommit_memory 0 case
> e.g. the swapper_space.nr_pages addition was brought in at a time when
> it was very necessary, but usually overestimates now (or last time I
> thought about it). The main thing to look out for is running the same
> memory grabber twice in quick succession: not nice if it succeeds the
> first time, but not the second, just because of some transient effect
> that its old pages are temporarily uncounted.
>

That's right - there can be sudden and huge changes in pages used/free.

So any rate limiting tweak in there would have to be in terms of
number-of-pages rather than number-of-seconds.
-
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 13:22    [W:1.273 / U:0.860 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site