linux-kernel - Re: [PATCH v4 09/22] perf: Support overwrite mode for AUX area

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:	Tue, 09 Sep 2014 16:00:43 +0300
From:	Alexander Shishkin <alexander.shishkin@...ux.intel.com>
To:	Peter Zijlstra <peterz@...radead.org>
Cc:	Ingo Molnar <mingo@...hat.com>, linux-kernel@...r.kernel.org,
	Robert Richter <rric@...nel.org>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Mike Galbraith <efault@....de>,
	Paul Mackerras <paulus@...ba.org>,
	Stephane Eranian <eranian@...gle.com>,
	Andi Kleen <ak@...ux.intel.com>, kan.liang@...el.com
Subject: Re: [PATCH v4 09/22] perf: Support overwrite mode for AUX area

Peter Zijlstra <peterz@...radead.org> writes:

> On Tue, Sep 09, 2014 at 02:53:42PM +0300, Alexander Shishkin wrote:
>
>> We can infer where the new data starts from the timestamps in the trace
>> stream, so the decoder can take care of it (and that's how it's done at
>> the moment).
>
> So that means the data stream can be read from arbitrary locations,
> right? I can imagine not all data streams are always readable like that
> (for instance the perf datastream is not).
>
> Does it make sense to have the driver provide head,tail for this mode?
> In your case you can simply provide whatever, but for those where it
> matters they can ensure consistent data such that the stream might be
> recoverable.

Yes, there's no reason not to, and some HW might indeed benefit from
this.

Regards,
--
Alex
--
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/