Re: [PATCH] Sort kallsyms in name order: kernel shrinks by 30k

From: Keith Owens
Date: Tue May 11 2004 - 00:26:27 EST


On Tue, 11 May 2004 15:08:55 +1000,
Rusty Russell <rusty@xxxxxxxxxxxxxxx> wrote:
>Admittedly, anyone who sets CONFIG_KALLSYMS doesn't care about space,
>it's a fairly trivial change.
>
>Name: Sort Kallsyms for Stem Compression
>Status: Booted on 2.6.6
>Depends: Misc/kallsyms-include-aliases.patch.gz
>
>Leaving the symbols sorted by name rather than address, so stem
>compression works more effectively. Saves a little over 30k here.

Not sure this is a good idea. proc_pid_wchan() calls kallsyms_lookup()
and has been identified as a bottleneck on systems with a large number
of processes. top can consume a complete cpu out of 128 cpus, all
because of this bottleneck. I was toying with the idea of doing a
binary chop on the address lookup, but this patch prevents that fix.

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