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Date: Thu, 04 Dec 2014 19:24:00 -0000
Message-ID: <CADPb22R=t1AOhb2+YmFfsH2hVphAVHifV1b7kD-jZZD4J_ARHA@mail.gmail.com>
Subject: Re: [RFC] symbol lookup cache
From: Doug Evans <dje@google.com>
To: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: gdb-patches <gdb-patches@sourceware.org>, Joel Brobecker <brobecker@adacore.com>
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On Thu, Dec 4, 2014 at 11:15 AM, Jan Kratochvil
<jan.kratochvil@redhat.com> wrote:
> On Mon, 01 Dec 2014 09:23:49 +0100, Doug Evans wrote:
>> ..gdb_index helps speed things up for one objfile,
>> but when there are 100s (or 1000s) of shared
>> libraries, symbol lookup can still take awhile,
>> even with .gdb_index.
>> [I'm setting aside a planned change to basic
>> symbol lookup to use the index better.
>> We'll still, I think, want a cache even
>> with that change.]
>
> While I have no numbers personally I do not think GDB would still need a cache
> after that change.
>
> "Accelerate lookup_symbol_aux_objfile 85x" is so fast in a fraction of second
> because it traverses 146426 symtabs.  So 146426 is OK but 1979341 was not (it
> was in some way more than 1979341 before you refactored symtabs).

Just to make sure I understand correctly, the 85x is dwz-specific, right?