mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
To: Peter Zijlstra <peterz@infradead.org>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Ingo Molnar <mingo@redhat.com>,
	linux-kernel@vger.kernel.org,
	Arnaldo Carvalho de Melo <acme@kernel.org>
Subject: [PATCH] tools/perf: fix documentation for sysctls perf_event_paranoid and perf_event_mlock_kb
Date: Sun, 20 Aug 2017 14:39:20 +0300	[thread overview]
Message-ID: <150322916080.129746.11285255474738558340.stgit@buzz> (raw)

Fix misprint CAP_IOC_LOCK -> CAP_IPC_LOCK. This capability have nothing
to do with raw tracepoints. This part is about bypassing mlock limits.

Sysctl kernel.perf_event_paranoid = -1 allows raw and ftrace function
tracepoints without CAP_SYS_ADMIN.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
---
 Documentation/sysctl/kernel.txt |   13 ++++++++++++-
 tools/perf/util/evsel.c         |    4 +++-
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index bac23c198360..ce61d1fe08ca 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -61,6 +61,7 @@ show up in /proc/sys/kernel:
 - perf_cpu_time_max_percent
 - perf_event_paranoid
 - perf_event_max_stack
+- perf_event_mlock_kb
 - perf_event_max_contexts_per_stack
 - pid_max
 - powersave-nap               [ PPC only ]
@@ -654,7 +655,9 @@ Controls use of the performance events system by unprivileged
 users (without CAP_SYS_ADMIN).  The default value is 2.
 
  -1: Allow use of (almost) all events by all users
->=0: Disallow raw tracepoint access by users without CAP_IOC_LOCK
+     Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK
+>=0: Disallow ftrace function tracepoint by users without CAP_SYS_ADMIN
+     Disallow raw tracepoint access by users without CAP_SYS_ADMIN
 >=1: Disallow CPU event access by users without CAP_SYS_ADMIN
 >=2: Disallow kernel profiling by users without CAP_SYS_ADMIN
 
@@ -673,6 +676,14 @@ The default value is 127.
 
 ==============================================================
 
+perf_event_mlock_kb:
+
+Control size of per-cpu ring buffer not counted agains mlock limit.
+
+The default value is 512 + 1 page
+
+==============================================================
+
 perf_event_max_contexts_per_stack:
 
 Controls maximum number of stack frame context entries for
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 413f74df08de..5ed7056d1fd0 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2535,7 +2535,9 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target,
 		 "unprivileged users (without CAP_SYS_ADMIN).\n\n"
 		 "The current value is %d:\n\n"
 		 "  -1: Allow use of (almost) all events by all users\n"
-		 ">= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK\n"
+		 "      Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK\n"
+		 ">= 0: Disallow ftrace function tracepoint by users without CAP_SYS_ADMIN\n"
+		 "      Disallow raw tracepoint access by users without CAP_SYS_ADMIN\n"
 		 ">= 1: Disallow CPU event access by users without CAP_SYS_ADMIN\n"
 		 ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN\n\n"
 		 "To make this setting permanent, edit /etc/sysctl.conf too, e.g.:\n\n"

             reply	other threads:[~2017-08-20 11:49 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-08-20 11:39 Konstantin Khlebnikov [this message]
2017-08-22 15:55 ` Arnaldo Carvalho de Melo
2017-08-24  8:24 ` [tip:perf/core] perf: Fix " tip-bot for Konstantin Khlebnikov

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=150322916080.129746.11285255474738558340.stgit@buzz \
    --to=khlebnikov@yandex-team.ru \
    --cc=acme@kernel.org \
    --cc=alexander.shishkin@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®