linux-kernel - Re: [RFC] perf: need to expose sched_clock to correlate user samples with kernel samples

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:	Thu, 04 Apr 2013 17:29:23 +0100
From:	Pawel Moll <pawel.moll@....com>
To:	John Stultz <john.stultz@...aro.org>
Cc:	Peter Zijlstra <peterz@...radead.org>,
	David Ahern <dsahern@...il.com>,
	Stephane Eranian <eranian@...gle.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	LKML <linux-kernel@...r.kernel.org>,
	"mingo@...e.hu" <mingo@...e.hu>, Paul Mackerras <paulus@...ba.org>,
	Anton Blanchard <anton@...ba.org>,
	Will Deacon <Will.Deacon@....com>,
	"ak@...ux.intel.com" <ak@...ux.intel.com>,
	Pekka Enberg <penberg@...il.com>,
	Steven Rostedt <rostedt@...dmis.org>,
	Robert Richter <robert.richter@....com>,
	Richard Cochran <richardcochran@...il.com>
Subject: Re: [RFC] perf: need to expose sched_clock to correlate user
 samples with kernel samples

On Wed, 2013-04-03 at 18:50 +0100, John Stultz wrote:
> I get the reasoning around reusing the fd we already have, but is the 
> possibility of a dynamic chardev pathname really a big concern?

Well, in my particular development system I have no udev, so I had to
manually do "mknod". Perf syscall works out of the box. Of course one
could say it's my problem...

> I'm guessing the private_data on the perf file is already used?

Of course.

> Maybe can we extend the dynamic posix clock code to work on more then 
> just the chardev? 

The idea I'm following now is to make the dynamic clock framework even
more generic, so there could be a clock associated with an arbitrary
struct file * (the perf syscall is getting one with
anon_inode_getfile()). I don't know how to get this done yet, but I'll
give it a try and report.

Paweł


--
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/