2018-10-22 18:09:42

by Prateek Patel

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Subject: [PATCH V2] kmemleak: Add config to select auto scan

From: Sri Krishna chowdary <[email protected]>

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.

Signed-off-by: Sri Krishna chowdary <[email protected]>
Signed-off-by: Sachin Nikam <[email protected]>
Signed-off-by: Prateek <[email protected]>
---
v2:
* change config name to DEBUG_KMEMLEAK_AUTO_SCAN from DEBUG_KMEMLEAK_SCAN_ON
* use IS_ENABLED(...) instead of #ifdef ...
* update commit message according to config name
---
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 c958013..a14166d 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 877de4f..a614930 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1647,7 +1647,7 @@ 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);
@@ -2141,9 +2141,11 @@ 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");

--
2.1.4



2018-10-29 10:44:02

by Catalin Marinas

[permalink] [raw]
Subject: Re: [PATCH V2] kmemleak: Add config to select auto scan

On Mon, Oct 22, 2018 at 11:38:43PM +0530, Prateek Patel wrote:
> From: Sri Krishna chowdary <[email protected]>
>
> 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.
>
> Signed-off-by: Sri Krishna chowdary <[email protected]>
> Signed-off-by: Sachin Nikam <[email protected]>
> Signed-off-by: Prateek <[email protected]>

Looks fine to me.

Reviewed-by: Catalin Marinas <[email protected]>

2018-12-12 06:45:51

by Prateek Patel

[permalink] [raw]
Subject: Re: [PATCH V2] kmemleak: Add config to select auto scan

Hi Catalin,

Can you mark this patch as acknowledged so that it can be picked up by
the maintainer.

Adding Andrew.

Thanks,

On 10/29/2018 4:13 PM, Catalin Marinas wrote:
> On Mon, Oct 22, 2018 at 11:38:43PM +0530, Prateek Patel wrote:
>> From: Sri Krishna chowdary <[email protected]>
>>
>> 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.
>>
>> Signed-off-by: Sri Krishna chowdary <[email protected]>
>> Signed-off-by: Sachin Nikam <[email protected]>
>> Signed-off-by: Prateek <[email protected]>
> Looks fine to me.
>
> Reviewed-by: Catalin Marinas <[email protected]>

2018-12-12 10:16:11

by Catalin Marinas

[permalink] [raw]
Subject: Re: [PATCH V2] kmemleak: Add config to select auto scan

On Wed, Dec 12, 2018 at 12:14:29PM +0530, Prateek Patel wrote:
> On 10/29/2018 4:13 PM, Catalin Marinas wrote:
> > On Mon, Oct 22, 2018 at 11:38:43PM +0530, Prateek Patel wrote:
> > > From: Sri Krishna chowdary <[email protected]>
> > >
> > > 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.
> > >
> > > Signed-off-by: Sri Krishna chowdary <[email protected]>
> > > Signed-off-by: Sachin Nikam <[email protected]>
> > > Signed-off-by: Prateek <[email protected]>
> > Looks fine to me.
> >
> > Reviewed-by: Catalin Marinas <[email protected]>
>
> Can you mark this patch as acknowledged so that it can be picked up by the
> maintainer.

I thought Reviewed-by was sufficient. Anyway:

Acked-by: Catalin Marinas <[email protected]>