Re: [ANNOUNCE] New utility: 'trace'

From: Peter Zijlstra
Date: Wed Nov 17 2010 - 07:51:47 EST


On Wed, 2010-11-17 at 14:47 +0200, TÃrÃk Edwin wrote:
> I see --call-graph in the trace record -h output, but it doesn't seem
> to work on x86_64 for me.

If you want to unwind userspace you need to build everything with
framepointers -- sadly some people have been lobbying to remove
framepointers from all distro builds, even though on x86_64 its nearly
free (i386 does have a significant performance benefit, sadly).

There's some work on-going to simply copy out the top of stack and let
dwarves go wild at it in userspace, but that isn't done yet.

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