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]

Date:	Mon, 18 Sep 2006 19:04:22 +0100
From:	Alan Cox <alan@...rguk.ukuu.org.uk>
To:	"Frank Ch. Eigler" <fche@...hat.com>
Cc:	Ingo Molnar <mingo@...e.hu>, Paul Mundt <lethal@...ux-sh.org>,
	Mathieu Desnoyers <mathieu.desnoyers@...ymtl.ca>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	Jes Sorensen <jes@....com>, Andrew Morton <akpm@...l.org>,
	Tom Zanussi <zanussi@...ibm.com>,
	Richard J Moore <richardj_moore@...ibm.com>,
	Michel Dagenais <michel.dagenais@...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

Ar Llu, 2006-09-18 am 13:27 -0400, ysgrifennodd Frank Ch. Eigler:
> Unless one's worried about planetary-scale energy use, I see no point
> in multiplying overheads by "every box on the planet".

Because we are all paying for your debug stuff we aren't using. Systems
get slow and sucky by the death of a million cuts not by one stupid
action.

> Unfortunately, cases in which this sort of out-of-band markup would be
> sufficient are pretty much those exact same cases where it is not
> necessary.  Remember, the complex cases occur when the compiler munges
> up control flow and data accessability, so debuginfo cannot or does
> not correctly place the probes and their data gathering compatriots.

Which if understand you right you'd end up unmunging and reducing
performance for by reducing the options gcc has to make that critical
code go fast just so you know what register something is living in.

Alan
-
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/