perf_counter: Rename perf_counter_limit sysctl

Rename perf_counter_limit to perf_counter_max_sample_rate and
prohibit creation of counters with a known higher sample
frequency.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 344a659..9fd4e43 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -932,9 +932,9 @@
 	},
 	{
 		.ctl_name	= CTL_UNNUMBERED,
-		.procname	= "perf_counter_int_limit",
-		.data		= &sysctl_perf_counter_limit,
-		.maxlen		= sizeof(sysctl_perf_counter_limit),
+		.procname	= "perf_counter_max_sample_rate",
+		.data		= &sysctl_perf_counter_sample_rate,
+		.maxlen		= sizeof(sysctl_perf_counter_sample_rate),
 		.mode		= 0644,
 		.proc_handler	= &proc_dointvec,
 	},