From: Tom Tromey <tom@tromey.com>
To: Tom Tromey <tom@tromey.com>
Cc: Simon Marchi <simark@simark.ca>, gdb-patches@sourceware.org
Subject: Re: [RFA 08/15] Remove readin and compunit_symtab fields from psymtab
Date: Sat, 06 Oct 2018 01:24:00 -0000 [thread overview]
Message-ID: <87zhvreujr.fsf@tromey.com> (raw)
In-Reply-To: <87lg7mi5al.fsf@tromey.com> (Tom Tromey's message of "Thu, 27 Sep 2018 23:01:38 -0600")
>>>>> "Tom" == Tom Tromey <tom@tromey.com> writes:
>>>>> "Simon" == Simon Marchi <simark@simark.ca> writes:
Simon> As Pedro pointed out a few times, unordered_map is an hash map with open
Simon> hashing. So we change what was previously a single pointer dereference
Simon> to a lookup in a hash table, followed with a linear search in a linked
Simon> list. If this map is looked up very frequently, maybe we should consider
Simon> using an htab_t instead? Some profiling data would help, but it seems
Simon> like psymtab_read_in_p is called quite a bit when looking up symbols...
[...]
Tom> I still haven't tried any performance measurements.
Tom> I'm not quite sure what to try.
I ran the gdb.perf tests and on some tests, it seems that the results
are within the noise; but on backtrace (2048) and skip-function-3000 (4000)
gdb is about 4% slower. I don't know if this is enough to worry about.
Tom
next prev parent reply other threads:[~2018-10-06 1:24 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-10 22:25 [RFA 00/15] Work toward making psymtabs reusable Tom Tromey
2018-05-10 22:25 ` [RFA 06/15] Change create_demangled_names_hash to take an objfile_per_bfd_storage Tom Tromey
2018-07-18 2:52 ` Simon Marchi
2018-05-10 22:25 ` [RFA 02/15] Remove some unneeded psymtab initializations Tom Tromey
2018-07-17 15:27 ` Simon Marchi
2018-07-18 2:29 ` Simon Marchi
2018-05-10 22:25 ` [RFA 11/15] Allocate the address map on the psymtab obstack Tom Tromey
2018-07-18 14:08 ` Simon Marchi
2018-05-10 22:25 ` [RFA 08/15] Remove readin and compunit_symtab fields from psymtab Tom Tromey
2018-07-18 3:34 ` Simon Marchi
2018-07-18 18:56 ` Tom Tromey
2018-09-28 5:02 ` Tom Tromey
2018-10-06 1:24 ` Tom Tromey [this message]
2018-10-07 22:04 ` Simon Marchi
2018-10-08 0:01 ` Tom Tromey
2018-05-10 22:25 ` [RFA 05/15] Simplify calls to init_psymbol_list Tom Tromey
2018-07-18 2:51 ` Simon Marchi
2018-09-23 21:12 ` Tom Tromey
2018-05-10 22:25 ` [RFA 01/15] Move some declarations to mdebugread.h Tom Tromey
2018-07-17 15:20 ` Simon Marchi
2018-05-10 22:25 ` [RFA 14/15] Make psymtab_storage::free_psymtabs private Tom Tromey
2018-07-18 14:36 ` Simon Marchi
2018-09-23 21:13 ` Tom Tromey
2018-05-10 22:25 ` [RFA 10/15] Introduce objfile::reset_psymtabs Tom Tromey
2018-07-18 14:04 ` Simon Marchi
2018-05-10 22:25 ` [RFA 15/15] Move psymtabs to their own obstack Tom Tromey
2018-07-18 14:41 ` Simon Marchi
2018-09-23 21:34 ` Tom Tromey
2018-05-10 22:25 ` [RFA 07/15] Change symbol_set_names to take an objfile_per_bfd_storage Tom Tromey
2018-05-10 22:25 ` [RFA 03/15] Remove parameters from start_psymtab_common Tom Tromey
2018-07-17 15:41 ` Simon Marchi
2018-05-10 22:25 ` [RFA 04/15] Change add_psymbol_to_list to use an enum Tom Tromey
2018-07-18 2:41 ` Simon Marchi
2018-05-10 22:45 ` [RFA 09/15] Introduce class psymtab_storage Tom Tromey
2018-07-18 14:02 ` Simon Marchi
2018-05-11 10:53 ` [RFA 12/15] Move more allocations to psymtab obstack Tom Tromey
2018-07-18 14:24 ` Simon Marchi
2018-05-11 10:53 ` [RFA 13/15] Add psymtab_storage::allocate_dependencies Tom Tromey
2018-07-18 14:32 ` Simon Marchi
2018-09-23 21:25 ` Tom Tromey
2018-06-18 14:42 ` [RFA 00/15] Work toward making psymtabs reusable Tom Tromey
2018-07-16 16:33 ` Tom Tromey
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