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Re: comment on today's changes
- To: drepper@cygnus.com
- Subject: Re: comment on today's changes
- From: Geoff Keating <geoffk@ozemail.com.au>
- Date: Tue, 29 Dec 1998 23:55:07 +1100
- CC: libc-hacker@cygnus.com
- References: <r267awy9om.fsf@happy.cygnus.com>
> Reply-To: drepper@cygnus.com (Ulrich Drepper)
> From: Ulrich Drepper <drepper@cygnus.com>
> Date: 28 Dec 1998 00:04:09 -0800
> Why I needed this is because I'm looking into rtld improvements and
> the data I got is quite intersting. It showed that the symbol
> relocation at startup time (even for lazy binding!) requires 70-80% of
> the startup time. For non-lazy loading it's of course more (and
> therefore for MIPS it's always that high). This was just the
> acknowledgment I needed to justify what will come sometime soon.
Here's an interesting question: how does that time break down into
a) actual computation (searching for symbols and suchlike)
b) reading in pages (either really from disk, or just setting up
TLB entries for them as they are accessed)
c) copying pages on write?
On my system, it's (b) and (c) that are the big costs. Symbol
versioning cut (a) a lot.
--
Geoffrey Keating <geoffk@ozemail.com.au>