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Date: Fri, 20 Apr 2007 12:15:43 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Balbir Singh <balbir@in.ibm.com>
Cc: nagar@watson.ibm.com, jlan@sgi.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH -mm] Taskstats fix the structure members alignment issue
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On Fri, 20 Apr 2007 22:13:41 +0530
Balbir Singh <balbir@in.ibm.com> wrote:

> 
> We broke the the alignment of members of taskstats to the 8 byte boundary
> with the CSA patches. In the current kernel, the taskstats structure is
> not suitable for use by 32 bit applications in a 64 bit kernel.
> 

ugh, that was bad of us.

> ...
> The patch adds an __attribute__((aligned(8))) to the
> taskstats structure members so that 32 bit applications using taskstats
> can work with a 64 bit kernel.

But there might be 32-bit applications out there which are using the
present wrong structure?

otoh, I assume that those applications would be using taskstats.h and would
hence encounter this bug and we would have heard about it, is that correct?

otoh^2, 32-bit applications running under 32-bit kernels will presently be
functioning correctly, and your change will require that those applications
be recompiled, I think?


This patch looks like 2.6.20 and 2.6.21 material, but very carefully...