linux-kernel - Re: [PATCH 3/3] ftrace: add ability to only trace swapper tasks

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: <20081204080629.GB32594@elte.hu>
Date:	Thu, 4 Dec 2008 09:06:29 +0100
From:	Ingo Molnar <mingo@...e.hu>
To:	Steven Rostedt <rostedt@...dmis.org>
Cc:	linux-kernel@...r.kernel.org,
	Andrew Morton <akpm@...ux-foundation.org>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Dave Hansen <dave@...ux.vnet.ibm.com>,
	containers@...ts.osdl.org, Eric Biederman <ebiederm@...ssion.com>,
	Sukadev Bhattiprolu <sukadev@...ux.vnet.ibm.com>,
	"Serge E. Hallyn" <serue@...ibm.com>,
	Steven Rostedt <srostedt@...hat.com>
Subject: Re: [PATCH 3/3] ftrace: add ability to only trace swapper tasks


* Steven Rostedt <rostedt@...dmis.org> wrote:

> From: Steven Rostedt <srostedt@...hat.com>
> 
> Impact: New feature
> 
> This patch lets the swapper tasks of all CPUS be filtered by the
> set_ftrace_pid file.
> 
> If '0' is echoed into this file, then all the idle tasks (aka swapper)
> is flagged to be traced.  This affects all CPU idle tasks.
> 
> Signed-off-by: Steven Rostedt <srostedt@...hat.com>
> ---
>  kernel/trace/ftrace.c |   74 +++++++++++++++++++++++++++++++++++++++++-------
>  1 files changed, 63 insertions(+), 11 deletions(-)

okay, i've applied it - but i dont like the extra complexity of +50 lines 
at all.

This is an area where the 'PID namespaces via struct pid pointers' model 
breaks down and forces collateral complexity into other subsystems, and 
where a simple integer based filter is so intuitive.

Eric, can you see any way to simplify this? It looks horrible.

	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/