linux-kernel - [PATCH 3.14 72/77] perf session: Do not fail on processing out of order event

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: <20150114072228.316364896@linuxfoundation.org>
Date:	Tue, 13 Jan 2015 23:23:52 -0800
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	stable@...r.kernel.org,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Jiri Olsa <jolsa@...nel.org>, Ingo Molnar <mingo@...nel.org>,
	Andi Kleen <ak@...ux.intel.com>,
	Corey Ashford <cjashfor@...ux.vnet.ibm.com>,
	David Ahern <dsahern@...il.com>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Matt Fleming <matt.fleming@...el.com>,
	Namhyung Kim <namhyung@...nel.org>,
	Paul Mackerras <paulus@...ba.org>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Stephane Eranian <eranian@...gle.com>,
	Arnaldo Carvalho de Melo <acme@...hat.com>,
	Zhiqiang Zhang <zhangzhiqiang.zhang@...wei.com>
Subject: [PATCH 3.14 72/77] perf session: Do not fail on processing out of order event

3.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jiri Olsa <jolsa@...nel.org>

commit f61ff6c06dc8f32c7036013ad802c899ec590607 upstream.

Linus reported perf report command being interrupted due to processing
of 'out of order' event, with following error:

  Timestamp below last timeslice flush
  0x5733a8 [0x28]: failed to process type: 3

I could reproduce the issue and in my case it was caused by one CPU
(mmap) being behind during record and userspace mmap reader seeing the
data after other CPUs data were already stored.

This is expected under some circumstances because we need to limit the
number of events that we queue for reordering when we receive a
PERF_RECORD_FINISHED_ROUND or when we force flush due to memory
pressure.

Reported-by: Linus Torvalds <torvalds@...ux-foundation.org>
Signed-off-by: Jiri Olsa <jolsa@...nel.org>
Acked-by: Ingo Molnar <mingo@...nel.org>
Cc: Andi Kleen <ak@...ux.intel.com>
Cc: Corey Ashford <cjashfor@...ux.vnet.ibm.com>
Cc: David Ahern <dsahern@...il.com>
Cc: Frederic Weisbecker <fweisbec@...il.com>
Cc: Ingo Molnar <mingo@...nel.org>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Matt Fleming <matt.fleming@...el.com>
Cc: Namhyung Kim <namhyung@...nel.org>
Cc: Paul Mackerras <paulus@...ba.org>
Cc: Peter Zijlstra <a.p.zijlstra@...llo.nl>
Cc: Stephane Eranian <eranian@...gle.com>
Link: http://lkml.kernel.org/r/1417016371-30249-1-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>
[zhangzhiqiang: backport to 3.10:
 - adjust context
 - commit f61ff6c06d struct events_stats was defined in tools/perf/util/event.h
   while 3.10 stable defined in tools/perf/util/hist.h.
 - 3.10 stable there is no pr_oe_time() which used for debug.
 - After the above adjustments, becomes same to the original patch:
   https://github.com/torvalds/linux/commit/f61ff6c06dc8f32c7036013ad802c899ec590607
]
Signed-off-by: Zhiqiang Zhang <zhangzhiqiang.zhang@...wei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 tools/perf/util/hist.h    |    1 +
 tools/perf/util/session.c |    5 +++--
 2 files changed, 4 insertions(+), 2 deletions(-)

--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -36,6 +36,7 @@ struct events_stats {
 	u32 nr_invalid_chains;
 	u32 nr_unknown_id;
 	u32 nr_unprocessable_samples;
+	u32 nr_unordered_events;
 };
 
 enum hist_column {
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -638,8 +638,7 @@ int perf_session_queue_event(struct perf
 		return -ETIME;
 
 	if (timestamp < s->ordered_samples.last_flush) {
-		printf("Warning: Timestamp below last timeslice flush\n");
-		return -EINVAL;
+		s->stats.nr_unordered_events++;
 	}
 
 	if (!list_empty(sc)) {
@@ -1135,6 +1134,8 @@ static void perf_session__warn_about_err
 			    "Do you have a KVM guest running and not using 'perf kvm'?\n",
 			    session->stats.nr_unprocessable_samples);
 	}
+	if (session->stats.nr_unordered_events != 0)
+		ui__warning("%u out of order events recorded.\n", session->stats.nr_unordered_events);
 }
 
 volatile int session_done;


--
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/