linux-kernel - [tip:perf/core] perf kvm: Guest userspace samples should not be lumped with host uspace

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Message-ID: <tip-7c0f4a4113ba5de7898c246eeaeee4c23d94b887@git.kernel.org>
Date:	Wed, 25 Jul 2012 12:18:18 -0700
From:	tip-bot for David Ahern <dsahern@...il.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	acme@...hat.com, linux-kernel@...r.kernel.org, hpa@...or.com,
	mingo@...nel.org, peterz@...radead.org, namhyung@...nel.org,
	jolsa@...hat.com, fweisbec@...il.com, dsahern@...il.com,
	tglx@...utronix.de
Subject: [tip:perf/core] perf kvm:
  Guest userspace samples should not be lumped with host uspace

Commit-ID:  7c0f4a4113ba5de7898c246eeaeee4c23d94b887
Gitweb:     http://git.kernel.org/tip/7c0f4a4113ba5de7898c246eeaeee4c23d94b887
Author:     David Ahern <dsahern@...il.com>
AuthorDate: Fri, 20 Jul 2012 17:25:48 -0600
Committer:  Arnaldo Carvalho de Melo <acme@...hat.com>
CommitDate: Wed, 25 Jul 2012 11:29:46 -0300

perf kvm: Guest userspace samples should not be lumped with host uspace

e.g., perf kvm --host  --guest report -i perf.data --stdio -D
shows:

1 599127912065356 0x143b8 [0x48]: PERF_RECORD_SAMPLE(IP, 5): 5671/5676: 0x7fdf95a061c0 period: 1 addr: 0
... chain: nr:2
.....  0: ffffffffffffff80
.....  1: fffffffffffffe00
 ... thread: qemu-kvm:5671
 ...... dso: <not found>

(IP, 5) means sample in guest userspace. Those samples should not be lumped
into the VMM's host thread. i.e, the report output:

    56.86%  qemu-kvm  [unknown]         [u] 0x00007fdf95a061c0

With this patch the output emphasizes it is a guest userspace hit:

    56.86%  [guest/5671]  [unknown]         [u] 0x00007fdf95a061c0

Looking at 3 VMs (2 64-bit, 1 32-bit) with each running a CPU bound
process (openssl speed), perf report currently shows:

  93.84%  117726   qemu-kvm  [unknown]   [u] 0x00007fd7dcaea8e5

which is wrong. With this patch you get:

  31.50%   39258   [guest/18772]  [unknown]   [u] 0x00007fd7dcaea8e5
  31.50%   39236   [guest/11230]  [unknown]   [u] 0x0000000000a57340
  30.84%   39232   [guest/18395]  [unknown]   [u] 0x00007f66f641e107

Tested-by: Jiri Olsa <jolsa@...hat.com>
Signed-off-by: David Ahern <dsahern@...il.com>
Cc: Frederic Weisbecker <fweisbec@...il.com>
Cc: Ingo Molnar <mingo@...nel.org>
Cc: Jiri Olsa <jolsa@...hat.com>
Cc: Namhyung Kim <namhyung@...nel.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Link: http://lkml.kernel.org/r/1342826756-64663-4-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>
---
 tools/perf/util/session.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 8e48559..90ee39d 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -918,7 +918,9 @@ static struct machine *
 {
 	const u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
 
-	if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL && perf_guest) {
+	if (perf_guest &&
+	    ((cpumode == PERF_RECORD_MISC_GUEST_KERNEL) ||
+	     (cpumode == PERF_RECORD_MISC_GUEST_USER))) {
 		u32 pid;
 
 		if (event->header.type == PERF_RECORD_MMAP)
--
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