linux-kernel - [PATCH] perf tools: fix guest mode monitoring on AMD

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-next>] [day] [month] [year] [list]

Date:	Mon, 27 Feb 2012 18:33:51 +0100
From:	Stephane Eranian <eranian@...gle.com>
To:	linux-kernel@...r.kernel.org
Cc:	acme@...hat.com, robert.richter@....com, peterz@...radead.org,
	mingo@...e.hu, joro@...tes.org, gleb@...hat.com
Subject: [PATCH] perf tools: fix guest mode monitoring on AMD

Commit:

1aed267 perf kvm: Do guest-only counting by default
 
introduced a bug on AMD systems whereby simple commands:

$ perf stat ls
Performance counter stats for 'ls':
                 0 cycles                    #    0.000 GHz                    
       0.003704596 seconds time elapsed

would not count anything anymore. Same results for perf record.

I tracked it down to guest mode exclusion being enabled
by default leading to attr->exclude_guest = 1. When
not operating under any sort of virtualization, this
causes the PMU not to count anything.

The fix disables guest exclusion by default.

Signed-off-by: Stephane Eranian <eranian@...gle.com>
---

diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index 8109a90..c1017b3 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -6,7 +6,7 @@
  * XXX We need to find a better place for these things...
  */
 bool perf_host  = true;
-bool perf_guest = false;
+bool perf_guest = true;
 
 void event_attr_init(struct perf_event_attr *attr)
 {
--
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/