From: Jan Kratochvil <jan.kratochvil@redhat.com>
To: Simon Marchi <simon.marchi@polymtl.ca>
Cc: Tom Tromey <tom@tromey.com>, Pedro Alves <palves@redhat.com>,
gdb@sourceware.org
Subject: Re: Multi-threaded dwarf parsing
Date: Wed, 24 Feb 2016 21:28:00 -0000 [thread overview]
Message-ID: <20160224212823.GA18899@host1.jankratochvil.net> (raw)
In-Reply-To: <345f3571aa56d4e9b6f6cbf4fa552f5f@simark.ca>
On Wed, 24 Feb 2016 21:37:24 +0100, Simon Marchi wrote:
> What can cause CUs to be interlinked with each other?
I did not remember, from what I am checking now it is due to dwz:
https://sourceware.org/git/?p=dwz.git;a=blob;f=dwz.c
That is a DWARF size reduction tool (by DWARF optimization, not by any
compression).
All the CUs get queued there due to its DW_AT_import:
process_imported_unit_die()->maybe_queue_comp_unit()
Without dwz I could not reproduce the queueing problem. IIRC there was some
but I admit I may not remember it right.
BTW expanding one CU is also not cheap, just its .debug_info part can be
around 1MB:
readelf -wi libwebkitgtk-1.0.so.0.5.2.debug|grep '^ *<0>'|perl -lne 'BEGIN{$l=0;} /^\s*<0><([0-9a-f]+)>/ or die;$x=eval "0x$1";print(($x-$l)." ".$_);$l=$x;'|sort -nr
But that is a sub-second delay not much of a real problem.
Jan
next prev parent reply other threads:[~2016-02-24 21:28 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 [this message]
2016-02-24 21:10 ` Pedro Alves
2016-02-24 21:22 ` Jan Kratochvil
2016-02-25 3:31 ` Tom Tromey
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