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

[Adrian Bunk <bunk@stusta.de>]

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

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
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       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed