linux-kernel - Re: [PATCH] perf: remove PERF_SAMPLE

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] [day] [month] [year] [list]

Date:	Thu, 27 Aug 2009 15:35:02 +0200
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	Peter Zijlstra <peterz@...radead.org>,
	Steven Rostedt <rostedt@...dmis.org>,
	Arjan van de Ven <arjan@...radead.org>,
	Paul Mackerras <paulus@...ba.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Christoph Hellwig <hch@...radead.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] perf: remove PERF_SAMPLE_RAW

On Thu, Aug 27, 2009 at 10:43:21AM +0200, Ingo Molnar wrote:
> * Peter Zijlstra <peterz@...radead.org> wrote:
> 
> > Apparently people think trace-events became an ABI the moment perf 
> > exported them, regardless what the text surrounding 
> > PERF_SAMPLE_RAW said about the opaqueness of the data provided.
> 
> Well it's still opaque and the descriptor of what it means is in 
> debugfs so it's not an ABI as the comment says.
> 
> > I'm not willing to make anything trace related into an ABI, hence 
> > remove this.
> 
> This removes quite a bit of nice functionality we already have, so i 
> think it's (way) too heavy handed.
> 
> I think what we want is the golden middle: a per tracepoint 
> property. I.e. we would provide:
> 
>     TRACE_EVENT_STABLE()
> 
> or TRACE_EVENT_CORE() or TRACE_EVENT_ABI() - which carries a 'will 
> maintain this as an ABI' promise from the maintainer who adds it.


Why? The format files stand to avoid that.

I don't understand this debate.


> Also, tracepoints are a unidirectional channel of information - in 
> practice those are way easier to handle as an ABI than other ABIs 
> such as behavior, semantics, etc. So i'd expect there to be a 
> healthy set of 'stable' tracepoints.
> 
> 	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/