From: Naresh Rapolu <nrapolu@purdue.edu>
To: linux-kernel@vger.kernel.org
Subject: Hardware performance events are not counted by "perf" in a 2.6.31.12 KVM guest
Date: Fri, 26 Mar 2010 22:03:10 -0400 [thread overview]
Message-ID: <4BAD675E.3050600@purdue.edu> (raw)
Hello,
"perf" tool does not count hardware performance events ( cache misses
etc) in a KVM guest ( Ubuntu 9.10 karmic, 2.6.31-14-generic kernel)
on Xeon 5530 quad-core. The host is 2.6.28 kernel , Ubuntu 8.04
LTS, Hardy.
readfile.sh reads in a large file (1430 lines), which should cause
cache-misses.
root@multicore4-vm3:/usr/src/linux-2.6.31.12/tools/perf# ./perf stat -r
5 -- bash readfile.sh
Performance counter stats for 'bash readfile.sh' (5 runs):
11002.207467 task-clock-msecs # 1.042 CPUs ( +-
10.834% )
3480 context-switches # 0.000 M/sec (
+- 19.017% )
2238 CPU-migrations # 0.000 M/sec (
+- 29.488% )
482299 page-faults # 0.044 M/sec (
+- 0.141% )
0 cycles # 0.000
M/sec ( +- nan% )
0 instructions # nan
IPC ( +- nan% )
0 cache-references # 0.000 M/sec (
+- nan% )
0 cache-misses # 0.000 M/sec (
+- nan% )
10.560510393 seconds time elapsed ( +- 11.401% )
Do I need to make some configuration changes to enable hardware events
? A similar question was posted recently here :
http://lkml.org/lkml/2010/3/18/342 but no response !
Any help would be greatly appreciated.
Thanks,
Naresh Rapolu.
next reply other threads:[~2010-03-27 2:09 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-27 2:03 Naresh Rapolu [this message]
2010-03-28 11:57 ` Hardware performance events are not counted by "perf" in a 2.6.31.12 KVM guest Joerg Roedel
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