From: Vince Weaver <vincent.weaver@maine.edu>
Date: Thu, 23 Jul 2015 13:16:55 -0400 (EDT)
To: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
cc: linux-man@vger.kernel.org, linux-kernel@vger.kernel.org,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Borislav Petkov <bp@alien8.de>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        "H. Peter Anvin" <hpa@zytor.com>, Kaixu Xia <kaixu.xia@linaro.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Mike Galbraith <efault@gmx.de>, Robert Richter <rric@kernel.org>,
        Stephane Eranian <eranian@google.com>,
        Thomas Gleixner <tglx@linutronix.de>, adrian.hunter@intel.com,
        kan.liang@intel.com, markus.t.metzger@intel.com,
        mathieu.poirier@linaro.org, Vince Weaver <vincent.weaver@maine.edu>
Subject: [patch 11/11] perf_event_open.2: add possibility of EBUSY error
Message-ID: <alpine.DEB.2.20.1507231316050.3742@vincent-weaver-1.umelst.maine.edu>
User-Agent: Alpine 2.20 (DEB 67 2015-01-07)
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1776
Lines: 53


Linux 4.1 added the possibility of perf_event_open() returning
EBUSY if an existing exclusive event controls the PMU.

This was introduced by the following commit:

	commit bed5b25ad9c8a2f5d735ef0bc746ec870c01c1b0
	Author: Alexander Shishkin <alexander.shishkin@linux.intel.com>
	Date:   Fri Jan 30 12:31:06 2015 +0200

	perf: Add a pmu capability for "exclusive" events

	Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
	Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
	Cc: Borislav Petkov <bp@alien8.de>
	Cc: Frederic Weisbecker <fweisbec@gmail.com>
	Cc: H. Peter Anvin <hpa@zytor.com>
	Cc: Kaixu Xia <kaixu.xia@linaro.org>
	Cc: Linus Torvalds <torvalds@linux-foundation.org>
	Cc: Mike Galbraith <efault@gmx.de>
	Cc: Paul Mackerras <paulus@samba.org>
	Cc: Robert Richter <rric@kernel.org>
	Cc: Stephane Eranian <eranian@google.com>
	Cc: Thomas Gleixner <tglx@linutronix.de>
	Cc: acme@infradead.org
	Cc: adrian.hunter@intel.com
	Cc: kan.liang@intel.com
	Cc: markus.t.metzger@intel.com
	Cc: mathieu.poirier@linaro.org

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

diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2
index b3cd93f..3d03786 100644
--- a/man2/perf_event_open.2
+++ b/man2/perf_event_open.2
@@ -2911,6 +2911,11 @@ the cgroup file descriptor in
 .I pid
 is not valid.
 .TP
+.BR EBUSY " (since Linux 4.1)"
+.\" bed5b25ad9c8a2f5d735ef0bc746ec870c01c1b0
+Returned if another event already has exclusive
+access to the PMU.
+.TP
 .B EFAULT
 Returned if the
 .I attr
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/