From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Vince Weaver <vweaver1@eecs.utk.edu>
Cc: linux-kernel@vger.kernel.org, fbuihuu@gmail.com, mingo@elte.hu,
paulus@samba.org, acme@redhat.com
Subject: Re: perf: regression -- missing /sys/devices/system/cpu/perf_events
Date: Tue, 24 May 2011 16:11:46 +0200 [thread overview]
Message-ID: <1306246306.18455.36.camel@twins> (raw)
In-Reply-To: <alpine.DEB.2.00.1105240955050.9203@cl320.eecs.utk.edu>
On Tue, 2011-05-24 at 09:59 -0400, Vince Weaver wrote:
> I know this is a bit late, but for some reason our users sit on these
> things and then they aren't willing to take it up with linux-kernel
> themselves
>
> > > > commit 15ac9a395a753cb28c674e7ea80386ffdff21785
> > > > Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
> > > > Date: Mon Sep 6 15:51:45 2010 +0200
> > > >
> > > > perf: Remove the sysfs bits
>
> removed the /sys/devices/system/cpu/perf_events
> I thought things in /sys were stable ABI?
if only.. that stuff changes way too often (not to say that's a good
thing).
> Apparently it's common for people to have scripts to check if
> perf_events is available in a kernel by checking the existence of
> /sys/devices/system/cpu/perf_events, even if they didn't use the
> files within.
A much more reliable way is simply doing the syscall and seeing what
happens. But if you want to poke around in sysfs, /sys/bus/event_source/
is the new location.
> Now that 2.6.38 kernels are starting to hit the distros we're getting
> complaints that it's missing.
Urgh, they'd been broken long before.. and I hadn't received any
complaints from people about that. I didn't see the point in keeping
broken interfaces around, esp. since with moving to multiple-pmu they
don't make any sense at all.
Ingo, any idea what to do here?
next prev parent reply other threads:[~2011-05-24 14:12 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-24 13:59 perf: regression -- missing /sys/devices/system/cpu/perf_events Vince Weaver
2011-05-24 14:11 ` Peter Zijlstra [this message]
2011-05-24 17:42 ` Vince Weaver
2011-05-24 19:48 ` Ingo Molnar
2011-05-24 20:12 ` Vince Weaver
2011-05-24 20:57 ` David Ahern
2011-05-24 21:29 ` Ingo Molnar
2011-06-03 21:54 ` [patch] perf - comment /proc/sys/kernel/perf_event_paranoid to be part of user ABI Vince Weaver
2011-06-04 10:23 ` Ingo Molnar
2011-06-04 11:06 ` [tip:perf/core] perf: Comment " tip-bot for Vince Weaver
2011-05-24 21:37 ` perf: regression -- missing /sys/devices/system/cpu/perf_events Ingo Molnar
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