LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Jiri Olsa <jolsa@kernel.org>
To: Arnaldo Carvalho de Melo <acme@kernel.org>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: lkml <linux-kernel@vger.kernel.org>,
	Ingo Molnar <mingo@kernel.org>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Namhyung Kim <namhyung@kernel.org>,
	David Ahern <dsahern@gmail.com>, Andi Kleen <andi@firstfloor.org>,
	Mark Rutland <mark.rutland@arm.com>
Subject: [PATCH 02/10] perf: Fix leader for removed sibling event in perf_group_detach
Date: Thu, 24 Aug 2017 18:27:29 +0200
Message-ID: <20170824162737.7813-3-jolsa@kernel.org> (raw)
In-Reply-To: <20170824162737.7813-1-jolsa@kernel.org>

Mark reported warning in x86_perf_event_update caused
by reading unscheduled leader of an event that was
already removed from the group.

As he pointed out we don't properly reset event's leader
once it's been detached from the group and he posted the
attached fix.

[1] https://marc.info/?l=linux-kernel&m=150238662928203&w=2

Originally-From: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 kernel/events/core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index d704e23914bf..30e30e94ea32 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1727,6 +1727,7 @@ static void perf_group_detach(struct perf_event *event)
 	if (event->group_leader != event) {
 		list_del_init(&event->group_entry);
 		event->group_leader->nr_siblings--;
+		event->group_leader = event;
 		goto out;
 	}
 
-- 
2.9.5

  parent reply index

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-08-24 16:27 [PATCH 00/10] perf: inherit_stat related fixes Jiri Olsa
2017-08-24 16:27 ` [PATCH 01/10] perf/x86: Add warning on proper cpu during event's update Jiri Olsa
2017-08-28 19:24   ` Peter Zijlstra
2017-08-24 16:27 ` Jiri Olsa [this message]
2017-08-28 19:23   ` [PATCH 02/10] perf: Fix leader for removed sibling event in perf_group_detach Peter Zijlstra
2017-08-24 16:27 ` [PATCH 03/10] perf: Make sure we read only scheduled events Jiri Olsa
2017-08-28 19:23   ` Peter Zijlstra
2017-09-01  7:21     ` Jiri Olsa
2017-08-24 16:27 ` [PATCH 04/10] perf record: Set read_format for inherit_stat Jiri Olsa
2017-08-29 21:20   ` [tip:perf/core] " tip-bot for Jiri Olsa
2017-08-24 16:27 ` [PATCH 05/10] perf report: Add dump_read function Jiri Olsa
2017-08-29 21:20   ` [tip:perf/core] " tip-bot for Jiri Olsa
2017-08-24 16:27 ` [PATCH 06/10] perf values: Fix thread index bug Jiri Olsa
2017-08-29 21:21   ` [tip:perf/core] " tip-bot for Jiri Olsa
2017-08-24 16:27 ` [PATCH 07/10] perf values: Fix allocation check Jiri Olsa
2017-08-29 21:21   ` [tip:perf/core] " tip-bot for Jiri Olsa
2017-08-24 16:27 ` [PATCH 08/10] perf values: Zero value buffers Jiri Olsa
2017-08-29 21:21   ` [tip:perf/core] " tip-bot for Jiri Olsa
2017-08-24 16:27 ` [PATCH 09/10] perf report: Group stat values on global event id Jiri Olsa
2017-08-29 21:22   ` [tip:perf/core] " tip-bot for Jiri Olsa
2017-08-24 16:27 ` [PATCH 10/10] perf stat: Support inherit/no-inherit terms Jiri Olsa
2017-08-24 16:30   ` Andi Kleen
2017-08-24 16:45     ` Jiri Olsa
2017-08-25 18:57       ` Arnaldo Carvalho de Melo

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20170824162737.7813-3-jolsa@kernel.org \
    --to=jolsa@kernel.org \
    --cc=a.p.zijlstra@chello.nl \
    --cc=acme@kernel.org \
    --cc=alexander.shishkin@linux.intel.com \
    --cc=andi@firstfloor.org \
    --cc=dsahern@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=mingo@kernel.org \
    --cc=namhyung@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git
	git clone --mirror https://lore.kernel.org/lkml/8 lkml/git/8.git
	git clone --mirror https://lore.kernel.org/lkml/9 lkml/git/9.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git