From: Tom Tromey <tom@tromey.com>
To: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Simon Marchi <simon.marchi@polymtl.ca>,
Tom Tromey <tom@tromey.com>, Pedro Alves <palves@redhat.com>,
gdb@sourceware.org
Subject: Re: Multi-threaded dwarf parsing
Date: Thu, 25 Feb 2016 03:31:00 -0000 [thread overview]
Message-ID: <871t81qxvs.fsf@tromey.com> (raw)
In-Reply-To: <20160224202519.GA10251@host1.jankratochvil.net> (Jan Kratochvil's message of "Wed, 24 Feb 2016 21:25:19 +0100")
Jan> With .gdb_index GDB still has startup performance problems during
Jan> full CU expansions, that is struct symtab and struct symbol.
My branch "lazily-read-function-bodies" addressed this issue. It
changed CU expansion to skip reading function bodies until needed. This
was good for a decent speedup; my notes say ~40%. I didn't finish this
branch, though -- it still needed a bit of work to expand a function
when a by-address lookup was done.
It's possible, but harder, to go even farther than this -- that is,
unify symtabs and psymtabs and make CU expansion completely lazy. At
one point I had a rather complicated plan for this.
For what it's worth, in my current debugging, I do notice psymtab
reading, but I never notice CU expansion. I'm not sure if I'm just
lucky or if it's because the CU expansion problem is exacerbated by dwz,
which I'm of course not using during development.
Tom
prev parent reply other threads:[~2016-02-25 3:31 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-24 2:45 Simon Marchi
2016-02-24 11:06 ` Pedro Alves
2016-02-24 15:30 ` Tom Tromey
2016-02-24 16:43 ` Simon Marchi
2016-02-24 19:50 ` Tom Tromey
2016-02-24 20:25 ` Jan Kratochvil
2016-02-24 20:37 ` Simon Marchi
2016-02-24 21:28 ` Jan Kratochvil
2016-02-24 21:10 ` Pedro Alves
2016-02-24 21:22 ` Jan Kratochvil
2016-02-25 3:31 ` Tom Tromey [this message]
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