public inbox for gdb-patches@sourceware.org
 help / color / mirror / Atom feed
From: Tom Tromey <tom@tromey.com>
To: Eli Zaretskii <eliz@gnu.org>
Cc: Tom Tromey <tom@tromey.com>,
	 gdb-patches@sourceware.org, luis.machado@arm.com
Subject: Re: Two observations using GDB 13 snapshot
Date: Wed, 28 Dec 2022 09:35:33 -0700	[thread overview]
Message-ID: <87wn6bbi5m.fsf@tromey.com> (raw)
In-Reply-To: <835ydw20bw.fsf@gnu.org> (Eli Zaretskii's message of "Tue, 27 Dec 2022 20:00:51 +0200")

Eli> And one more thing: this is a native 32-bit Windows build of GDB, so
Eli> it has DWARF2 info in PE-COFF file, not in ELF.  Maybe this could
Eli> explain the difference?  Or maybe the C++ code is a factor?

The object file format shouldn't make a difference.  The DWARF code just
reads the appropriate sections (this code hasn't changed since GDB 12)
and the actual parsing is independent of the object file format.

C++ being used in the executable would possibly explain the difference
between reading GDB and reading Emacs, but I don't think it could
explain the performance difference between GDB 12 and 13 reading the
same executable.

I don't have a theory for what could be wrong.  Maybe profiling is the
best way.  It might also be interesting to verify that the
parallel_for_each in gdb/dwarf2/read.c is the culprit; that can be done
by setting breakpoints before and after it and measuring the time it
takes to "cont" from one to the other.  The idea of this is that if the
new reader is the source of the problem, it would show up here.

Tom

  parent reply	other threads:[~2022-12-28 16:37 UTC|newest]

Thread overview: 63+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-12-17 17:42 Eli Zaretskii
2022-12-19 10:07 ` Luis Machado
2022-12-19 12:48   ` Eli Zaretskii
2022-12-19 14:08     ` Luis Machado
2022-12-19 14:45       ` Eli Zaretskii
2022-12-19 21:18         ` Tom Tromey
2022-12-20  3:26           ` Eli Zaretskii
2022-12-23  3:34             ` Simon Marchi
2022-12-23  8:05               ` Eli Zaretskii
2022-12-24 17:57             ` Tom Tromey
2022-12-24 18:13               ` Eli Zaretskii
2022-12-27 17:19                 ` Tom Tromey
2022-12-27 18:00                   ` Eli Zaretskii
2022-12-28 12:35                     ` Luis Machado
2022-12-28 16:35                     ` Tom Tromey [this message]
2022-12-28 17:35                       ` Eli Zaretskii
2022-12-28 22:47                         ` Tom Tromey
2022-12-29 15:18                           ` Eli Zaretskii
2022-12-29 18:17                             ` Tom Tromey
2022-12-29 18:36                               ` John Baldwin
2022-12-29 19:13                               ` Eli Zaretskii
2022-12-29 20:22                                 ` Simon Marchi
2022-12-30 14:31                                   ` Eli Zaretskii
2023-01-03 19:44                                     ` Christian Biesinger
2023-01-03 20:18                                       ` Eli Zaretskii
2023-01-03 20:34                                         ` Christian Biesinger
2023-01-03 21:34                                           ` Simon Marchi
2023-01-03 21:43                                             ` Christian Biesinger
2023-01-04  1:03                                             ` Tom Tromey
2023-01-04 18:10                                             ` Eli Zaretskii
2023-01-04 22:33                                               ` Tom Tromey
2023-01-05  7:11                                                 ` Eli Zaretskii
2023-01-05 14:49                                                   ` Christian Biesinger
2023-01-05 15:12                                                     ` Eli Zaretskii
2023-01-06 20:55                                                   ` Tom Tromey
2023-01-05 18:06                                               ` Torbjorn SVENSSON
2023-01-07  6:30 ` Eli Zaretskii
2023-01-07  9:14   ` Andreas Schwab
2023-01-07  9:32     ` Eli Zaretskii
2023-01-07 10:00       ` Andreas Schwab
2023-01-07 10:51         ` Eli Zaretskii
2023-01-07 13:04           ` Andreas Schwab
2023-01-07 13:54             ` Eli Zaretskii
2023-01-07 13:59               ` Andreas Schwab
2023-01-07 14:12                 ` Eli Zaretskii
2023-01-07 14:23                   ` Andreas Schwab
2023-01-07 14:29                     ` Eli Zaretskii
2023-01-07 14:40                       ` Andreas Schwab
2023-01-07 15:07                         ` Eli Zaretskii
2023-01-07 15:40                           ` Andreas Schwab
2023-01-07 16:10                             ` Eli Zaretskii
2023-01-07 16:15                               ` Eli Zaretskii
2023-01-07 16:16                               ` Hannes Domani
2023-01-07 16:22                                 ` Eli Zaretskii
2023-01-07 17:39                                 ` Andreas Schwab
2023-01-07 18:08                                   ` Eli Zaretskii
2023-01-07 18:26                                     ` Andreas Schwab
2023-01-07 18:38                                       ` Eli Zaretskii
2023-01-07 19:26                                         ` Andreas Schwab
2023-01-07 19:35                                           ` Eli Zaretskii
2023-01-07 18:28                                     ` Hannes Domani
2023-01-07 19:25                                       ` Andreas Schwab
2023-01-07 15:07                       ` Eli Zaretskii

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87wn6bbi5m.fsf@tromey.com \
    --to=tom@tromey.com \
    --cc=eliz@gnu.org \
    --cc=gdb-patches@sourceware.org \
    --cc=luis.machado@arm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).