Re: Oops in a driver while using SLUB as a SLAB allocator

[Hugh Dickins]

On Thu, 21 Jun 2007, Christoph Lameter wrote:
> On Fri, 22 Jun 2007, Hugh Dickins wrote:
> 
> > However... what gives you confidence that flush_dcache_page is
> > never applied to other slab pages?
> 
> Flush dcache page is supposed to run on pages not objects of varying 
> length. It is suprising that this has not lead to earlier problems.
> Objects allocated this way may straddle a page boundary under some 
> conditions and in that case virt_to_page may not lead to a page that 
> covers the complete object that is supposed to be flushed. Hopefully the 
> "size" of the allocated object were whole pages.

No, that's the wrong way round.  Neither ARM nor PA-RISC expects
flush_dcache_page to flush any dcache when given a slab allocation:
they just expect it to pass through, not to oops.

Hugh
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