linux-kernel - Re: Fix powerTOP regression with 2.6.39-rc5

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:	Sun, 8 May 2011 23:08:18 +0200
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	Arjan van de Ven <arjan@...ux.intel.com>
Cc:	Steven Rostedt <rostedt@...dmis.org>, Ingo Molnar <mingo@...e.hu>,
	David Sharp <dhsharp@...gle.com>,
	Vaibhav Nagarnaik <vnagarnaik@...gle.com>,
	Michael Rubin <mrubin@...gle.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: Re: Fix powerTOP regression with 2.6.39-rc5

On Sat, May 07, 2011 at 10:59:36AM -0700, Arjan van de Ven wrote:
> On 5/7/2011 10:20 AM, Steven Rostedt wrote:
> >On Sat, 2011-05-07 at 16:44 +0200, Ingo Molnar wrote:
> >>* Steven Rostedt<rostedt@...dmis.org>  wrote:
> >>
> >>>2) we separate perf from ftrace and keep the "stable" ABI for perf, and let
> >>>ftrace advance into a more efficient tracer.
> >>The thing is, ftrace is still largely separated from perf, and this is why this
> >>regression came in: a random tracing 'cleanup' churn was done to 'tracing'
> >>which broke PowerTop.
> >>
> >>Look at the commit itself:
> >>
> >>   e6e1e2593592: tracing: Remove lock_depth from event entry
> >>
> >>Clearly you didnt even *realize* that there's a whole tooling world behind this
> >>mechanism ...
> >Note, I discussed this change with Frederic and he totally agreed with
> >me on removing it. In fact, we are in discussions about getting rid of
> >pid, preempt-count, and irq flags as well. But according to your logic,
> >that is a no go. I guess Frederic also does not *realize* there's a
> >whole tooling world behind this mechanism too.
> 
> btw if you remove some of these, how is userland supposed to find
> out if an event happened in irq context?

You can use the irq events for that.
--
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/