Re: Leaks in trace reported by kmemleak

From: Catalin Marinas
Date: Thu Oct 22 2009 - 09:09:56 EST


Hi Zdenek,

On Tue, 2009-10-20 at 11:58 +0200, Zdenek Kabelac wrote:
> I've tested your git with updates - and here is my experience:
>
> I'm still able to get FP leaks printed even with the print of
> more-then-once appearanc.

I updated the kmemleak.git tree and in my tests it reduced the false
positives significantly. I dropped the two-pass scanning patch and I
added a new one which checks whether objects were modified since the
previous leak suspicion and only report them if unmodified (using
csum_partial for checksum calculation). This works well with linked
lists since list deletion modifies the prev/next pointers of those left
in the list (like in the debug_objects case).

> Also jiffies might be eventually more readable via data/time - but
> this can be preprocessed via script.

Jiffies is still useful to ensure it's the same object or a new one
allocated in the same function (and possibly false positive). I added
another bit of information - the age of an object in seconds.msecs.

--
Catalin

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