From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Andi Kleen <andi@firstfloor.org>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org, acme@redhat.com,
eranian@google.com, Andi Kleen <ak@linux.intel.com>
Subject: Re: [PATCH 05/34] perf, x86: Report PEBS event in a raw format
Date: Tue, 23 Oct 2012 15:50:50 +0200 [thread overview]
Message-ID: <1351000250.13456.34.camel@twins> (raw)
In-Reply-To: <20121023133000.GX16230@one.firstfloor.org>
On Tue, 2012-10-23 at 15:30 +0200, Andi Kleen wrote:
> > Also, there's an alignment issue there, the raw.data is 32bit offset,
> > the record is u64 aligned, leaving the output stream offset, wrecking
> > things.
>
> Can you explain more? Not sure I understand.
PERF_SAMPLE_RAW has a u32 size header and starts the data after that.
This means you PERF_SAMPLE_RAW output ends up on a u32 aligned end
address -- assuming the data is a u64 multiple, this is not good.
> It appears to work at least.
It would on x86, I'm fairly sure it'll break on things like SPARC. We
used to have checks in the userspace code to warn for this on x86 as
well. Not sure if that's still there.
Hmm, so in kernel/events/core.c:perf_prepare_sample() there's a
WARN_ON_ONCE() in the PERF_SAMPLE_RAW branch that should trigger with
this.
> >
> > And as with any ABI extension, it should come with useful userspace to
> > make use of it.
>
> There are already scripts available to use it, see Feng's patchkit.
That's a whole other patchkit, meaning this doesn't belong here.
I never can seem to figure out how to use the scripts mess :/ acme, is
there anything we could do to make that stuff usable? There's a ton of
crap under scripts/ but I don't even know how to get that stuff to run.
What's more, all that nonsense is in weird languages I don't do either,
making it less useful than usual.
In short, I don't consider script/ to be proper userspace since its
bloody useless.
next prev parent reply other threads:[~2012-10-23 13:51 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-18 23:19 perf PMU support for Haswell v3 Andi Kleen
2012-10-18 23:19 ` [PATCH 01/34] perf, x86: Add PEBSv2 record support Andi Kleen
2012-10-18 23:19 ` [PATCH 02/34] perf, x86: Basic Haswell PMU support v2 Andi Kleen
2012-10-18 23:19 ` [PATCH 03/34] perf, x86: Basic Haswell PEBS " Andi Kleen
2012-10-23 12:01 ` Peter Zijlstra
2012-10-23 13:31 ` Andi Kleen
2012-10-18 23:19 ` [PATCH 04/34] perf, x86: Support the TSX intx/intx_cp qualifiers Andi Kleen
2012-10-23 12:09 ` Peter Zijlstra
2012-10-23 13:33 ` Andi Kleen
2012-10-18 23:19 ` [PATCH 05/34] perf, x86: Report PEBS event in a raw format Andi Kleen
2012-10-23 12:31 ` Peter Zijlstra
2012-10-23 12:39 ` Stephane Eranian
2012-10-23 13:45 ` Andi Kleen
2012-10-23 13:58 ` Stephane Eranian
2012-10-23 14:11 ` Andi Kleen
2012-10-23 13:30 ` Andi Kleen
2012-10-23 13:50 ` Peter Zijlstra [this message]
2012-10-23 13:57 ` Andi Kleen
2012-10-24 7:50 ` Ingo Molnar
2012-10-18 23:19 ` [PATCH 06/34] perf, kvm: Support the intx/intx_cp modifiers in KVM arch perfmon emulation v2 Andi Kleen
2012-10-23 12:36 ` Peter Zijlstra
2012-10-23 12:53 ` Gleb Natapov
2012-10-23 13:35 ` Andi Kleen
2012-10-23 13:36 ` Andi Kleen
2012-10-23 13:05 ` [06/34] " Gleb Natapov
2012-10-23 13:20 ` Andi Kleen
2012-10-24 13:37 ` Gleb Natapov
2012-10-18 23:19 ` [PATCH 07/34] perf, x86: Support PERF_SAMPLE_ADDR on Haswell Andi Kleen
2012-10-18 23:19 ` [PATCH 08/34] perf, x86: Support Haswell v4 LBR format Andi Kleen
2012-10-23 12:37 ` Peter Zijlstra
2012-10-18 23:19 ` [PATCH 09/34] perf, x86: Disable LBR recording for unknown LBR_FMT Andi Kleen
2012-10-18 23:19 ` [PATCH 10/34] perf, x86: Support LBR filtering by INTX/NOTX/ABORT Andi Kleen
2012-10-18 23:19 ` [PATCH 11/34] perf, tools: Add abort,notx,intx branch filter options to perf report -j Andi Kleen
2012-10-23 12:44 ` Peter Zijlstra
2012-10-18 23:19 ` [PATCH 12/34] perf, tools: Support sorting by intx, abort branch flags Andi Kleen
2012-10-18 23:19 ` [PATCH 13/34] perf, x86: Support full width counting on Haswell Andi Kleen
2012-10-18 23:19 ` [PATCH 14/34] perf, x86: Avoid checkpointed counters causing excessive TSX aborts Andi Kleen
2012-10-23 13:03 ` Peter Zijlstra
2012-10-23 13:22 ` Andi Kleen
2012-10-23 13:05 ` Peter Zijlstra
2012-10-18 23:19 ` [PATCH 15/34] perf, core: Add a concept of a weightened sample Andi Kleen
2012-10-23 13:13 ` Peter Zijlstra
2012-10-23 13:19 ` Andi Kleen
2012-10-18 23:19 ` [PATCH 16/34] perf, x86: Support weight samples for PEBS Andi Kleen
2012-10-23 13:15 ` Peter Zijlstra
2012-10-23 14:05 ` Andi Kleen
2012-10-18 23:19 ` [PATCH 17/34] perf, tools: Add support for weight v2 Andi Kleen
2012-10-18 23:19 ` [PATCH 18/34] perf, tools: Handle XBEGIN like a jump Andi Kleen
2012-10-18 23:19 ` [PATCH 19/34] perf, x86: Support for printing PMU state on spurious PMIs v2 Andi Kleen
2012-10-18 23:19 ` [PATCH 20/34] perf, core: Add generic transaction flags Andi Kleen
2012-10-18 23:19 ` [PATCH 21/34] perf, x86: Add Haswell specific transaction flag reporting Andi Kleen
2012-10-18 23:19 ` [PATCH 22/34] perf, tools: Add support for record transaction flags Andi Kleen
2012-10-18 23:19 ` [PATCH 23/34] perf, tools: Point --sort documentation to --help Andi Kleen
2012-10-18 23:19 ` [PATCH 24/34] perf, tools: Add browser support for transaction flags Andi Kleen
2012-10-18 23:19 ` [PATCH 25/34] perf, tools: Move parse_events error printing to parse_events_options Andi Kleen
2012-10-18 23:19 ` [PATCH 26/34] perf, tools: Support events with - in the name Andi Kleen
2012-10-18 23:19 ` [PATCH 27/34] perf, x86: Report the arch perfmon events in sysfs Andi Kleen
2012-10-18 23:19 ` [PATCH 28/34] tools, perf: Add a precise event qualifier Andi Kleen
2012-10-18 23:19 ` [PATCH 29/34] perf, x86: Add Haswell TSX event aliases Andi Kleen
2012-10-18 23:19 ` [PATCH 30/34] perf, tools: Add perf stat --transaction v2 Andi Kleen
2012-10-18 23:19 ` [PATCH 31/34] perf, x86: Add a Haswell precise instructions event Andi Kleen
2012-10-18 23:19 ` [PATCH 32/34] perf, tools: Support generic events as pmu event names v2 Andi Kleen
2012-10-18 23:19 ` [PATCH 33/34] perf, tools: Default to cpu// for events v2 Andi Kleen
2012-10-18 23:19 ` [PATCH 34/34] perf, tools: List kernel supplied event aliases in perf list v2 Andi Kleen
2012-10-19 9:13 ` perf PMU support for Haswell v3 Andi Kleen
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