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perf: Fix documentation for sysctls perf_event_paranoid and perf_event_mlock_kb

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>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/150322916080.129746.11285255474738558340.stgit@buzz
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Konstantin Khlebnikov 8 years ago
parent
commit
ac0bb6b72f
2 changed files with 15 additions and 2 deletions
  1. 12 1
      Documentation/sysctl/kernel.txt
  2. 3 1
      tools/perf/util/evsel.c

+ 12 - 1
Documentation/sysctl/kernel.txt

@@ -61,6 +61,7 @@ show up in /proc/sys/kernel:
 - perf_cpu_time_max_percent
 - perf_cpu_time_max_percent
 - perf_event_paranoid
 - perf_event_paranoid
 - perf_event_max_stack
 - perf_event_max_stack
+- perf_event_mlock_kb
 - perf_event_max_contexts_per_stack
 - perf_event_max_contexts_per_stack
 - pid_max
 - pid_max
 - powersave-nap               [ PPC only ]
 - 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.
 users (without CAP_SYS_ADMIN).  The default value is 2.
 
 
  -1: Allow use of (almost) all events by all users
  -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
 >=1: Disallow CPU event access by users without CAP_SYS_ADMIN
 >=2: Disallow kernel profiling 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:
 perf_event_max_contexts_per_stack:
 
 
 Controls maximum number of stack frame context entries for
 Controls maximum number of stack frame context entries for

+ 3 - 1
tools/perf/util/evsel.c

@@ -2674,7 +2674,9 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target,
 		 "unprivileged users (without CAP_SYS_ADMIN).\n\n"
 		 "unprivileged users (without CAP_SYS_ADMIN).\n\n"
 		 "The current value is %d:\n\n"
 		 "The current value is %d:\n\n"
 		 "  -1: Allow use of (almost) all events by all users\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"
 		 ">= 1: Disallow CPU event access by users without CAP_SYS_ADMIN\n"
 		 ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN\n\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"
 		 "To make this setting permanent, edit /etc/sysctl.conf too, e.g.:\n\n"