[tip:perf/core] perf events: Fix event inherit fallout of precalculated headers

[tip-bot for Thomas Gleixner <tglx@linutronix.de>]

Commit-ID:  614b6780eb0c393d2fb49ff62d61f29b877bd07e
Gitweb:     http://git.kernel.org/tip/614b6780eb0c393d2fb49ff62d61f29b877bd07e
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Fri, 3 Dec 2010 16:24:32 -0200
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Sat, 4 Dec 2010 22:56:11 -0200

perf events: Fix event inherit fallout of precalculated headers

The precalculated header size is not updated when an event is inherited. That
results in bogus sample entries for all child events. Bug introduced in c320c7b.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ian Munsie <imunsie@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <alpine.LFD.2.00.1012031245220.2653@localhost6.localdomain6>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 kernel/perf_event.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index aede712..7961b27 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -6099,6 +6099,11 @@ inherit_event(struct perf_event *parent_event,
 	child_event->overflow_handler = parent_event->overflow_handler;
 
 	/*
+	 * Precalculate sample_data sizes
+	 */
+	perf_event__header_size(child_event);
+
+	/*
 	 * Link it up in the child's context:
 	 */
 	raw_spin_lock_irqsave(&child_ctx->lock, flags);