perf_counter: provide an mlock threshold Provide a threshold to relax the mlock accounting, increasing usability. Each counter gets perf_counter_mlock_kb for free. [ Impact: allow more mmap buffering ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> LKML-Reference: <20090505155437.112113632@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 8203d70..3b05c2b 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c

@@ -920,6 +920,14 @@
 		.mode		= 0644,
 		.proc_handler	= &proc_dointvec,
 	},
+	{
+		.ctl_name	= CTL_UNNUMBERED,
+		.procname	= "perf_counter_mlock_kb",
+		.data		= &sysctl_perf_counter_mlock,
+		.maxlen		= sizeof(sysctl_perf_counter_mlock),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
 #endif
 /*
  * NOTE: do not add new entries to this table unless you have read