Messages in this thread Patch in this message | | | From | Arnd Bergmann <> | Subject | [PATCH] spufs: always map local store non-guarded | Date | Thu, 2 Nov 2006 13:46:48 +0100 |
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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 <michael@ellerman.id.au> Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com> ---
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); } - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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