linux-kernel - Re: Using a new perf tool against an older kernel

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: <20110624001100.GD8058@somewhere.redhat.com>
Date:	Fri, 24 Jun 2011 02:11:03 +0200
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	Arun Sharma <asharma@...com>
Cc:	David Ahern <dsahern@...il.com>, linux-perf-users@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: Using a new perf tool against an older kernel

On Thu, Jun 23, 2011 at 12:39:54PM -0700, Arun Sharma wrote:
> On 6/23/11 7:22 AM, David Ahern wrote:
> 
> >I have not seen issues like this using newer perf userspace against
> >older kernels. For example, my laptop was running Fedora 14 (2.6.35) and
> >now Fedora 15 (2.6.38.8) and I typically use latest perf builds (e.g.,
> >testing patches).
> 
> I narrowed it down to PERF_SAMPLE_RAW:
> 
> perf record -ag -- sleep 1
> 
> is fine, but:
> 
> perf record -agR -- sleep 1
> 
> fails for me most of the time. The reason I needed to use the -R in
> the first place is that "perf script" fails on older kernels with:
> 
> Samples do not contain timestamps.
> 
> With the newer perf, I don't get errors, but the timestamp field is
> invalid. So I need to use the -R flag to get valid timestamps +
> stacktraces out of "perf script".

I'm confused, you first said it happens with new tools on older kernel.

Can you tell us which combination of kernel/user raises the error? and
which error.

Thanks!
--
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/