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Subject: Re: doublefault debugging (was Re: Linux v2.5.62 --- spontaneous
	reboots)
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Linus Torvalds <torvalds@transmeta.com>
Cc: "Martin J. Bligh" <mbligh@aracnet.com>, Ingo Molnar <mingo@elte.hu>,
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On Thu, 2003-02-20 at 16:54, Linus Torvalds wrote:
> Ok, the 4kB stack definitely won't work in real life, but that's because 
> we have some hopelessly bad stack users in the kernel. But the debugging 
> part would be good to try (in fact, it might be a good idea to keep the 
> 8kB stack, but with rather anal debugging. Just the "mcount" part should 
> do that).

You also need IRQ stacks to get down to 4K. The wrong pattern of ten
different IRQ handlers using a mere 200 bytes each will eventually
happen and eventually kill you otherwise.

> That ide_unregister() thing uses up >2kB in just one call! And there are 
> several in the 1.5kB range too, with a long list of ~500 byte offenders.

ide_unregister is a really stupid one. Its copying a struct mostly to
restore fields it shouldnt be restoring but should be setting in the 
allocator. I hadn't realised quite how bad it was. Added to the ide
shitlist


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