On Thu, 2006-11-02 at 13:46 +0100, Arnd Bergmann wrote: > When fixing spufs to map the 'mem' file backing store cacheable, > I incorrectly set the physical mapping to use both cache-inhibited > and guarded mapping, which resulted in a serious performance > degradation. > > Accessing the real local store memory needs to be cache-inhibited, > in order to maintain data consistency, but since it is actual > RAM, there is no point in a guarded mapping. > > Debugged-by: Michael Ellerman <[email protected]> > Signed-off-by: Arnd Bergmann <[email protected]> > --- Looks good, cheers Acked-by: Michael Ellerman <[email protected]> > > This fixes a regression in 2.6.19, please merge. > > Index: linux-2.6/arch/powerpc/platforms/cell/spufs/file.c > =================================================================== > --- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/file.c > +++ linux-2.6/arch/powerpc/platforms/cell/spufs/file.c > @@ -104,11 +104,11 @@ spufs_mem_mmap_nopage(struct vm_area_str > > if (ctx->state == SPU_STATE_SAVED) { > vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot) > - & ~(_PAGE_NO_CACHE | _PAGE_GUARDED)); > + & ~_PAGE_NO_CACHE); > page = vmalloc_to_page(ctx->csa.lscsa->ls + offset); > } else { > vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot) > - | _PAGE_NO_CACHE | _PAGE_GUARDED); > + | _PAGE_NO_CACHE); > page = pfn_to_page((ctx->spu->local_store_phys + offset) > >> PAGE_SHIFT); > } -- Michael Ellerman OzLabs, IBM Australia Development Lab wwweb: http://michael.ellerman.id.au phone: +61 2 6212 1183 (tie line 70 21183) We do not inherit the earth from our ancestors, we borrow it from our children. - S.M.A.R.T Person
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- From: Arnd Bergmann <[email protected]>
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