Thread (4 messages) 4 messages, 3 authors, 1998-07-23

Re: More info: 2.1.108 page cache performance on low memory

From: Rik van Riel <hidden>
Date: 1998-07-23 21:33:04

On 23 Jul 1998, Zlatko Calusic wrote:
One wrong way of fixing it is to limit page cache size, IMNSHO.

I tried the other way, to age page cache harder, and it looks like it
works very well. Patch is simple, so simple that I can't understand
nobody suggested (something like) it yet.
These solutions are somewhat the same, but your one may take
a little less computational power and has a tradeoff in the
fact that it is very inflexible.
quoted hunk ↗ jump to hunk
--- filemap.c.virgin   Tue Jul 21 18:41:30 1998
+++ filemap.c   Thu Jul 23 12:14:43 1998
+                       age_page(page);
+                       age_page(page);
                        age_page(page);
If I put only two age_page()s, there's still too much swapping for my
taste.
With three age_page()s, read performance is as expected, and still we
manage memory more efficiently than without page aging.
This only proves that three age_page()s are a good number
for _your_ computer and your workload.
Comments?
As Stephen put it so nicely when I (in a bad mood) proposed
another artificial limit:
" O no, another arbitrary limit in the kernel! "

And another one of Stephen's wisdoms (heavily paraphrased!):
" Good solutions are dynamic and/or self-tuning "
[Sorry Stephen, this was VERY heavily paraphrased :)]

Rik.
+-------------------------------------------------------------------+
| Linux memory management tour guide.        H.H.vanRiel@phys.uu.nl |
| Scouting Vries cubscout leader.      http://www.phys.uu.nl/~riel/ |
+-------------------------------------------------------------------+

--
This is a majordomo managed list.  To unsubscribe, send a message with
the body 'unsubscribe linux-mm me@address' to: majordomo@kvack.org
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help