linux-kernel - Re: [PATCH v3 1/5] perf_event: introduce 'inject' event and get HZ

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: <1262166357.7135.177.camel@laptop>
Date:	Wed, 30 Dec 2009 10:45:57 +0100
From:	Peter Zijlstra <peterz@...radead.org>
To:	Xiao Guangrong <xiaoguangrong@...fujitsu.com>
Cc:	Ingo Molnar <mingo@...e.hu>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Steven Rostedt <rostedt@...dmis.org>,
	Paul Mackerras <paulus@...ba.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3 1/5] perf_event: introduce 'inject' event and get HZ

On Wed, 2009-12-30 at 17:37 +0800, Xiao Guangrong wrote:
> > I really dislike the name, event injection to me would be like a write()
> > interface where you provide the actual event data to be stuffed in the
> > output stream.
> > 
> 
> Yes, it like write and it writes something form kernel to perf.
> And, i think this name is suitable for it's doing that injects an
> 'artificial' event, it's well if you have other name for it :-)

No, what I means is that you cannot actually inject an arbitrary event.
Sure it injects something, but that's pretty limited.

> > This just seems like a very weird way of getting data out. A kind of
> > like sysconf() but done very strange.
> > 
> 
> It's since some parameter is only used by perf, suce as HZ in this patch and
> 'relocation offset' in my other patchset, it also well if has better way to
> do it :-)

The thing is, this proposed interface is very much tied to perf and
makes it basically impossible for !perf to use. Whereas I can imagine
esp. the relocation offset to be interesting for other things. Basically
everything needing to resolve a kernel symbol.



--
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/