linux-kernel - Re: tracepoint maintainance models

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20060918043248.GB19843@elte.hu>
Date:	Mon, 18 Sep 2006 06:32:48 +0200
From:	Ingo Molnar <mingo@...e.hu>
To:	Karim Yaghmour <karim@...rsys.com>
Cc:	Theodore Tso <tytso@....edu>, Nicholas Miell <nmiell@...cast.net>,
	Paul Mundt <lethal@...ux-sh.org>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	Ingo Molnar <mingo@...hat.com>, Jes Sorensen <jes@....com>,
	Andrew Morton <akpm@...l.org>,
	Roman Zippel <zippel@...ux-m68k.org>,
	Tom Zanussi <zanussi@...ibm.com>,
	Richard J Moore <richardj_moore@...ibm.com>,
	"Frank Ch. Eigler" <fche@...hat.com>,
	Michel Dagenais <michel.dagenais@...ymtl.ca>,
	Mathieu Desnoyers <mathieu.desnoyers@...ymtl.ca>,
	Christoph Hellwig <hch@...radead.org>,
	Greg Kroah-Hartman <gregkh@...e.de>,
	Thomas Gleixner <tglx@...utronix.de>,
	William Cohen <wcohen@...hat.com>,
	"Martin J. Bligh" <mbligh@...igh.org>
Subject: Re: tracepoint maintainance models

* Karim Yaghmour <karim@...rsys.com> wrote:

> Theodore Tso wrote:
> > I *think* what Karim is trying to claim is that LTT also has some
> > dynamic capabilities, and isn't a pure static tracing system.  But if
> > that's the case, I don't understand why LTT and SystemTap can't just
> > merge and play nice together....
> 
> That's been the thrust of my intervention here. [...]

indeed, and i severely misunderstood your points in this regard. Now i 
have re-read some of your earlier points, and in particular:

>> And finally, do realize that in 2000 I personally contacted the head 
>> of the DProbes project IBM in order to foster common development, 
>> following which ltt was effectively modified in order to allow 
>> dynamic instrumentation of the kernel ...

and now i'm red faced - i was wrong about this fundamental aspect of 
your position. Please accept my apologies!

so regarding the big picture we are largely on the same page in essence 
i think - sub-issues non-withstanding :-) As long as LTT comes with a 
facility that allows the painless moving of a static LTT markup to a 
SystemTap script, that would come quite a bit closer to being acceptable 
for upstream acceptance in my opinion.

The curious bit is: why doesnt LTT integrate SystemTap yet? Is it the 
performance aspect? Some of the extensive hooking you do in LTT could be 
aleviated to a great degree if you used dynamic probes. For example the 
syscall entry hackery in LTT looks truly scary. I cannot understand that 
someone who does tracing doesnt see the fundamental strength of 
SystemTap - i think that in part must have lead to my mistake of 
assuming that you opposed SystemTap.

	Ingo
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/