[RFC PATCH v3 3/7] ktask: add /proc/sys/debug/ktask_max_threads

[Daniel Jordan]

Adds a proc file to control the maximum number of ktask threads in use
for any one job.  Its primary use is to aid in debugging.

Signed-off-by: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>
Reviewed-by: Steve Sistare <steven.sistare@xxxxxxxxxx>
Cc: Aaron Lu <aaron.lu@xxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Tim Chen <tim.c.chen@xxxxxxxxx>
---
 kernel/sysctl.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 557d46728577..e296906e609e 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -67,6 +67,7 @@
 #include <linux/bpf.h>
 #include <linux/mount.h>
 #include <linux/pipe_fs_i.h>
+#include <linux/ktask_internal.h>
 
 #include <linux/uaccess.h>
 #include <asm/processor.h>
@@ -1867,6 +1868,15 @@ static struct ctl_table debug_table[] = {
 		.extra1		= &zero,
 		.extra2		= &one,
 	},
+#endif
+#if defined(CONFIG_KTASK)
+	{
+		.procname	= "ktask_max_threads",
+		.data		= &ktask_max_threads,
+		.maxlen		= sizeof(ktask_max_threads),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
 #endif
 	{ }
 };
-- 
2.15.0