[PATCH 03/11] perf kvm: guest userspace samples should not be lumped with host uspace

From: David Ahern
Date: Fri Jul 20 2012 - 19:27:42 EST


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

Signed-off-by: David Ahern <dsahern@xxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
---
tools/perf/util/session.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

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)
--
1.7.10.1

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