Re: [PATCH] mm/kmemleak: add support for re-enable kmemleak at runtime

From: Catalin Marinas
Date: Sat Jan 18 2014 - 05:45:46 EST


On 18 Jan 2014, at 08:41, Jianguo Wu <wujianguo@xxxxxxxxxx> wrote:
> On 2014/1/17 20:04, Catalin Marinas wrote:
>> On Fri, Jan 17, 2014 at 09:40:02AM +0000, Jianguo Wu wrote:
>>> Now disabling kmemleak is an irreversible operation, but sometimes
>>> we may need to re-enable kmemleak at runtime. So add a knob to enable
>>> kmemleak at runtime:
>>> echo on > /sys/kernel/debug/kmemleak
>>
>> It is irreversible for very good reason: once it missed the initial
>> memory allocations, there is no way for kmemleak to build the object
>> reference graph and you'll get lots of false positives, pretty much
>> making it unusable.
>
> Do you mean we didn't trace memory allocations during kmemleak disable period,
> and these memory may reference to new allocated objects after re-enable?

Yes. Those newly allocated objects would be reported as leaks.

Catalin--
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