lkml.org 
[lkml]   [1998]   [Nov]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [2.1.130-3] Page cache DEFINATELY too persistant... feature?
Thanks for all the responses!  So its writes that are causing the
problem.

> In some situations this is a good readout. If the O/S is doing its job,
> then that 24Mb in swap is disused code and data pages that are rarely
> accessed, if at all. As a bonus, that 24Mb can now be used for cache and
> buffers to reduce disk accesses and really make the system fly.
Good point. In fact, the paged-out pages were mostly unused pages, I
think, because xosview did not show a high rate of page-ins. However,
due to the sheer AMOUNT of pages that were paged out, a large bit of
netscape got paged out also, which I was actually using. So it had to
page a bit before the scrollbar worked, then some for the back button,
etc :). The problem is not so much that the swapping was bad, as the
AMOUNT of swapping that was done; the page-cache should have been shrunk
also, I think.
Usually, though, after recovering from such an episode, the system
feels quite nice with 9.5Mb or so swapped to disk.... evidently thats
the portion of memory that wasn't used much.


> I agree a "free" report like the above can be alarming. However, the
> important things you need to compare with previous releases are
> a) How snappy interactive performance felt
> b) How quickly the "background" task of updating your Debian system
> completed
b) So, the upgrade that was causing the swapping took a bit longer.The
fact is the page-cache simply wasn't being used. It was just sitting
there taking up 33% of my RAM. So, normally, disk usage is reserved for
writes instead of writes plus paging in and out.
a) Interactive performance went DOWN. Netscape had to do some
page-ins to respond to anything :)


-BenRI

P.S. I take it that its OK to Cc people like this even if they're on
linux-kernel? Or is that bad form?

--
If E. Coli was a computer:
"OPERON.DLL: Mutation in LACTOSE.DLL. Entire system halted."

Benjamin Redelings I <>< http://sdcc13.ucsd.edu/~bredelin

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:45    [W:0.146 / U:0.216 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site