linux-kernel - Re: [PATCH 1/2] perf tools: Add reference timestamp to perf header

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:	Mon, 13 Dec 2010 19:06:13 +0100
From:	Peter Zijlstra <peterz@...radead.org>
To:	"David S. Ahern" <daahern@...co.com>
Cc:	Arnaldo Carvalho de Melo <acme@...stprotocols.net>,
	Frederic Weisbecker <fweisbec@...il.com>,
	linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] perf tools: Add reference timestamp to perf header

On Mon, 2010-12-13 at 11:01 -0700, David S. Ahern wrote:
> > Another problem with this approach is things like flight-recorder mode
> > where you constantly over-write your old data, you'd have to build some
> > trigger to always output a new record before you over-write the old one,
> > so there's always one consistent record around. Drift is an even more
> > serious problem here since flight-record more could be running for days
> > before (if ever) you dump it.
> 
> Ok. I was not aware flight-recorder mode was an option today.

You get it when you mmap the fd RO -- the only thing is you don't get a
consistent tail pointer so you have to fudge a bit.

But even if we didn't have it, we'd need a solution that would work once
we did grow 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/