linux-kernel - Re: Unified tracing buffer

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20080923232239.DC1E.KOSAKI.MOTOHIRO@jp.fujitsu.com>
Date:	Tue, 23 Sep 2008 23:36:26 +0900 (JST)
From:	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
To:	Masami Hiramatsu <mhiramat@...hat.com>
Cc:	kosaki.motohiro@...fujitsu.com, Martin Bligh <mbligh@...gle.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Mathieu Desnoyers <compudj@...stal.dyndns.org>,
	Steven Rostedt <rostedt@...dmis.org>, od@...ell.com,
	"Frank Ch. Eigler" <fche@...hat.com>,
	systemtap-ml <systemtap@...rces.redhat.com>
Subject: Re: Unified tracing buffer


> By the way, systemtap uses two modes;
> 
> - single-channel mode
>  In this mode, all cpus share one buffer channel to write and read.
>  each writer locks spinlock and write a probe-local data to buffer.
> 
> - per-cpu buffer mode
>  In this mode, we use an atomic sequential number for ordering data. If
>  user doesn't need it(because they have their own timestamps), they can
>  choose not to use that seq-number.

I can't imazine a merit of the single-channel mode.
Could you please explain it?

Because some architecture don't have fine grained timestamp?
if so, could you explain which architecture don't have it?



--
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/