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Subject: Re: Multithreaded core dumps
To: viro@math.psu.edu (Alexander Viro)
Date: Thu, 30 Aug 2001 10:12:49 +0100 (BST)
Cc: alan@lxorguk.ukuu.org.uk (Alan Cox), kmacy@netapp.com (Kip Macy),
        efeingold@mn.rr.com (Elan Feingold), linux-kernel@vger.kernel.org
In-Reply-To: <Pine.GSO.4.21.0108300457270.9879-100000@weyl.math.psu.edu> from "Alexander Viro" at Aug 30, 2001 05:03:59 AM
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From: Alan Cox <alan@lxorguk.ukuu.org.uk>
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> > The 2.4-ac tree supports dumping core.$pid for the threads that actually
> > died
> 
> ... and these dumps are not reliable.  Living thread may modify the
> contents of dump as it's being written out.  I.e. you are getting
> false alarms - inconsistent data that was never there.

That is mathematically insoluble. Think about an SMP system, you cannot stop
the other thread in instantaneously small time

Alan