From: Mike Gulick <mgulick@mathworks.com>
To: gdb@sourceware.org
Cc: mgulick@mathworks.com
Subject: Re: GDB memory usage with compressed debug info
Date: Thu, 18 Mar 2021 14:38:02 -0400 [thread overview]
Message-ID: <acf17b88-a914-4f17-7a49-07b82c01812e@mathworks.com> (raw)
In-Reply-To: <e68b723a-0cf9-0a53-6129-100abf608ba6@mathworks.com>
On 3/16/21 2:40 PM, Mike Gulick wrote:
> Hi,
>
> I'm observing that GDB memory usage is much higher when I have debug
> info compressed with 'objcopy --compress-debug-sections'. In a large
> C++ application, I see the instance with uncompressed debug info use
> 46GB VIRTUAL memory and 11GB RSS, and the instance with compressed debug
> info is using 46GB VIRTUAL memory and 42GB RSS. In case it matters, the
> debug info is separated from the original binary into its own file.
>
> It seems like GDB must load the full uncompressed debug info into memory
> when the underlying files are compressed?
>
> I'm currently using GDB 9.2. I checked the 10.1 NEWS and didn't see
> anything that looked like it would have changed this result, but I'm
> happy to give it a try if you think it might help.
>
> Is there any chance this could be improved with a patch to GDB, or is
> this just the nature of compressed debug data?
>
> Also, FYI, the NEWS link for the GDB 10.1 release on the GDB home page
> points to the NEWS file for the 9.1 release.
>
> Thanks!
>
> -Mike
I should add that this high memory usage only occurs when there is a
FILE:LINENUM breakpoint set (or pending). I can run the application
being debugged, observe that GDB's memory usage is around 11 or 12 GB,
then run 'b foobar.cpp:123', and the GDB memory usage will climb up to
42 GB. Interesting that symbolic breakpoints don't trigger this high
memory usage, but line-based breakpoints do. Does this seem expected?
Thanks,
Mike
next prev parent reply other threads:[~2021-03-18 18:38 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-16 18:40 Mike Gulick
2021-03-18 18:38 ` Mike Gulick [this message]
2021-03-22 18:09 ` Christian Biesinger
2021-03-24 19:59 ` Matt Rice
2021-03-24 22:52 ` Mike Gulick
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