From d53ce042277a94eadf9a8a31fc41fac54c67dec5 Mon Sep 17 00:00:00 2001
From: Sri Krishna chowdary <schowdary@nvidia.com>
Date: Fri, 28 Dec 2018 00:38:54 -0800
Subject: [PATCH] kmemleak: add config to select auto scan
Kmemleak scan can be cpu intensive and can stall user tasks at times. To
prevent this, add config DEBUG_KMEMLEAK_AUTO_SCAN to enable/disable auto
scan on boot up. Also protect first_run with DEBUG_KMEMLEAK_AUTO_SCAN as
this is meant for only first automatic scan.
Link: http://lkml.kernel.org/r/1540231723-7087-1-git-send-email-prpatel@nvidia.com
Signed-off-by: Sri Krishna chowdary <schowdary@nvidia.com>
Signed-off-by: Sachin Nikam <snikam@nvidia.com>
Signed-off-by: Prateek <prpatel@nvidia.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
lib/Kconfig.debug | 15 +++++++++++++++
mm/kmemleak.c | 10 ++++++----
2 files changed, 21 insertions(+), 4 deletions(-)
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index b3c91b9e32f8..2b5a4256e88b 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -593,6 +593,21 @@ config DEBUG_KMEMLEAK_DEFAULT_OFF
Say Y here to disable kmemleak by default. It can then be enabled
on the command line via kmemleak=on.
+config DEBUG_KMEMLEAK_AUTO_SCAN
+ bool "Enable kmemleak auto scan thread on boot up"
+ default y
+ depends on DEBUG_KMEMLEAK
+ help
+ Depending on the cpu, kmemleak scan may be cpu intensive and can
+ stall user tasks at times. This option enables/disables automatic
+ kmemleak scan at boot up.
+
+ Say N here to disable kmemleak auto scan thread to stop automatic
+ scanning. Disabling this option disables automatic reporting of
+ memory leaks.
+
+ If unsure, say Y.
+
config DEBUG_STACK_USAGE
bool "Stack utilization instrumentation"
depends on DEBUG_KERNEL && !IA64
diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 9c3d2dea0861..f9d9dc250428 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1650,7 +1650,7 @@ static void kmemleak_scan(void)
*/
static int kmemleak_scan_thread(void *arg)
{
- static int first_run = 1;
+ static int first_run = IS_ENABLED(CONFIG_DEBUG_KMEMLEAK_AUTO_SCAN);
pr_info("Automatic memory scanning thread started\n");
set_user_nice(current, 10);
@@ -2144,9 +2144,11 @@ static int __init kmemleak_late_init(void)
return -ENOMEM;
}
- mutex_lock(&scan_mutex);
- start_scan_thread();
- mutex_unlock(&scan_mutex);
+ if (IS_ENABLED(CONFIG_DEBUG_KMEMLEAK_AUTO_SCAN)) {
+ mutex_lock(&scan_mutex);
+ start_scan_thread();
+ mutex_unlock(&scan_mutex);
+ }
pr_info("Kernel memory leak detector initialized\n");