linux-kernel - [patch] perf_event_open.2: Exclude

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:	Wed, 11 Feb 2015 14:04:53 -0500 (EST)
From:	Vince Weaver <vincent.weaver@...ne.edu>
To:	"Michael Kerrisk (man-pages)" <mtk.manpages@...il.com>
cc:	linux-man@...r.kernel.org, linux-kernel@...r.kernel.org,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Paul Mackerras <paulus@...ba.org>,
	Ingo Molnar <mingo@...hat.com>,
	Arnaldo Carvalho de Melo <acme@...nel.org>
Subject: [patch] perf_event_open.2: Exclude_hv clarification


This manpage patch relates to the exclude_hv bit added to the kernel
in the following commit:

    exclude_hv; Linux 2.6.31
        commit 0475f9ea8e2cc030298908949e0d5da9f2fc2cfe
        Author: Paul Mackerras <paulus@...ba.org>

            perf_counters: allow users to count user, kernel and/or hypervisor events

            Signed-off-by: Paul Mackerras <paulus@...ba.org>

The updated manpage text points out that the exclude_hv 
"exclude hypervisor" bit only applies on hardware that 
supports this  feature (such as PowerPC)
and is silently ignored on other platforms such as x86.

This is a resend of the patch; the previous time I sent it
(http://thread.gmane.org/gmane.linux.man/7500) it did not
receive any comments.


Signed-off-by: Vince Weaver <vincent.weaver@...ne.edu>

diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2
index 39c8d8c..665aa31 100644
--- a/man2/perf_event_open.2
+++ b/man2/perf_event_open.2
@@ -856,10 +856,9 @@ If this bit is set, the count excludes events that happen in kernel-space.
 .IR "exclude_hv"
 If this bit is set, the count excludes events that happen in the
 hypervisor.
-This is mainly for PMUs that have built-in support for handling this
-(such as POWER).
-Extra support is needed for handling hypervisor measurements on most
-machines.
+This is mainly for PMUs that have built-in hardware support
+for this feature (such as POWER; this setting is silently
+ignored on x86).
 .TP
 .IR "exclude_idle"
 If set, don't count when the CPU is idle.
--
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/