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Date: Tue, 15 Jul 2008 13:28:14 -0500
From: Stacey Son <sson@freebsd.org>
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To: Andrew Gallatin <gallatin@cs.duke.edu>
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Cc: Kostik Belousov <kostikbel@gmail.com>, freebsd-arch@freebsd.org
Subject: Re: ksyms pseudo driver
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Andrew Gallatin wrote:
> Ah, now everything is perfectly clear to me.  Your method is
> very clever indeed.
>
> Just out of curiosity, how much memory will the entire symbol
> + strings table require?  How often do typical consumers (like dtrace)
> request them?

On an AMD64 "Generic" kernel with only the ksyms module loaded it is 
1523847 bytes.

lockstat(1M) will open and read /dev/ksyms once each time it is 
invoked.   For dtrace, it depends on the script but there shouldn't be 
any reason why it reads it more than once as well.

-stacey.