On Mon, 2006-07-10 at 22:08 +0200, Simen Thoresen wrote:
Hi all,
I think I've spotted a few stupidities (bugs) in the current version of kernel-utils (kernel-utils-2.4-13.1.80). <snip>
The kernel-utils package provides several 'kernel-type' functions - readahead and readahead_early and also the cpuspeed have a few problems;
readahead 'reads ahead' (stats to copy to cache for speedy access?) the files found in /etc/readahead.files. While most of these files are various images and common binaries, some are libraries which have been replaced by newer versions, thereby reducing the usefulness of readahead.
Readahead.early uses a different file (/etc/readahead.early.files) to cache useful system libraries, including a few kernel modules - for the 2.6.3-2.1.238.2 kernel.
Both readahead and readahead.early are installed as disabled. chkconfig lists them as 'off' in all runlevels.
<snip>
In a thread about undesirable swapping in the last few weeks, one poster suggested disabling both read-ahead processes entirely. This was for workstations. He claimed that he could see no difference in his normal daily operations when read-ahead was enabled. The benefit was that he no longer came to a grinding halt after a few days of sporadic heavy load when swap usage skyrocketed for no discernible reason.
It also became known in that thread that a brain-damaged "feature" related to VM swapping was going to be fixed in update 4 (IIRC). Further, the ill-effects of this could be reduced by setting a value that reduced "swappiness" of the system. Anyway, since disabling readaheads, swap usage never exceeded 768K. User is no fatter, no dumber but is much happier as lock up occurrences are once again below the levels expected in a M$ system! zzzziiiing! :-)