Re: [2.6 patch] i386: always use 4k stacks

Adrian Bunk
2005-12-18T15:57:35Z

On Sun, Dec 18, 2005 at 10:49:31AM -0500, Parag Warudkar wrote:
>
> On Dec 18, 2005, at 7:09 AM, Adrian Bunk wrote:
>
> >There is no workload where 8kB suits better.
>
> People have pointed out that there is currently at least one
> incompatibility introduced by 4K stacks and there may be many others

That's wrong.

My count of bug reports for problems with 4k stacks with in-kernel code
after Neil's patch went into -mm is still at 0.

> which are corner cases, that only occur under high load in obscure
> exceptional circumstances with large configurations and suitable
> nesting.

And this is not that much of an issue since most of these cases can and
have already been analyzed by static analysis to be below 3 kB stack
usage.

> Moreover for 64 bit architectures there is no proven point that 4Kb
> stacks are solving a specific problem there (Like the lowmem
> fragmentation on i386 for e.g.). Nor can we predict for sure that in
> future no type of functionality will require more stack. So taking
> away 8Kb stack size on such arches solves no known problems and
> introduces artificial limitations on code complexity.
>...

That's complete bullshit considering that we are talking about an
i386-only patch.

> Parag

cu
Adrian

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