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Re: kernel summit session on systemtap
- From: "R. J. Moore" <rasman at uk dot ibm dot com>
- To: Theodore Tso <tytso at mit dot edu>
- Cc: systemtap at sources dot redhat dot com
- Date: Mon, 22 Sep 2008 10:17:35 +0100
- Subject: Re: kernel summit session on systemtap
- References: <48D20A8F.4060307@uk.ibm.com> <20080918154629.GD9640@mit.edu>
Theodore Tso wrote:
I spent about a couple of hours trying to get kdump to work on my
laptop, and then gave up. That's another RAS tool which has mostly
ignored by the kernel development community, and deployability and
usability has been one of its problems...
Never had a problem with kdump, so your comment surprises me. Have you
documented your issues?
I admit that this is extreme debugging,
but if system tap won't even operate without a ton of extra junk present
then I see its application as being very limited indeed. Not everyone
will want to work at the assembler level, but if System Tap can, then
tools can be built that do code analysis to help generate and divine
probepoints. Much can be done knowing that nearly 100% of the code we
probe is generated by the one tool - gcc. In theory, what is generated
is deterministic, or the reverse engineering of it is.
My guess is that right now, the level 3 debugging experts at places
like Red Hat, IBM, Novell, etc., are the only people who find
SystemTap useful. The quick survey done at the kernel summit pretty
conclusively showed that most kernel developers haven't tried to use
it, ....
Why should you expect this (or kdump) to be solely for kernel
developers? Its for debuggers, which may or may not be the same set of
folks. And those who concern themselves with complex live scenarios are
often not the same folks - at least not willingly so. This tired old
view that stipulates all that goes on in a kernel is for an exclusive
clique of kernel developers is a nonsense.
Richard
--
Richard J Moore
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