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Message-ID: <661de9470603052339s42a9b72bqcef489bddb296803@mail.gmail.com>
Date: Mon, 6 Mar 2006 13:09:54 +0530
From: "Balbir Singh" <bsingharora@gmail.com>
To: "Dave Jones" <davej@redhat.com>, "Balbir Singh" <bsingharora@gmail.com>,
       "David S. Miller" <davem@davemloft.net>, linux-kernel@vger.kernel.org,
       ericvh@gmail.com, rminnich@lanl.gov
Subject: Re: 9pfs double kfree
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> The vast majority of people never run with slab poisoning enabled
> judging by the number of bugs it constantly turns up.
>

Agreed, maybe we could insist that developers enable these options and
test their patch with debugging enabled before posting them, but I
have a feeling that it would meet a lot of resistance :-). Doesn't
hurt to document it in Documentation/HOWTO or somewhere more
appropriate.

>  > kfree() will ignore NULL
>  > pointer, from the comments in kfree
>
> *nod*, poisoning the ptr would be a better idea.
>

Yes, I think this is a better idea.

>  > May we could have such a variant under CONFIG_DEBUG_SLAB if we needed
>  > and also change the variant kfree to BUG_ON() a NULL pointer.
>
> given the cost is just a ptr assignment in a slow path, I'd prefer
> it was non-optional, otherwise it'll be as underused as the other
> debugging options.
>

Yes, agreed.
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