Re: [PATCH] x86: use __GFP_NORETRY in the case of GFP_DMA with pci-nommu

Joerg Roedel
2008-09-05T10:44:12Z

On Fri, Sep 05, 2008 at 05:58:48PM +0900, FUJITA Tomonori wrote:
> Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
> ---
> arch/x86/kernel/pci-nommu.c | 3 +++
> 1 files changed, 3 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c
> index 526b2db..3495f88 100644
> --- a/arch/x86/kernel/pci-nommu.c
> +++ b/arch/x86/kernel/pci-nommu.c
> @@ -102,6 +102,9 @@ nommu_alloc_coherent(struct device *hwdev, size_t size,
> if (dma_mask == DMA_24BIT_MASK)
> gfp |= GFP_DMA;
> again:
> + if (gfp & GFP_DMA)
> + gfp |= __GFP_NORETRY;
> +

Huh? Why that? The __GFP_NORETRY is a hint from the caller to the page
allocator on how aggressive it should try to allocate memory. I don't
think the DMA code should touch those flags unless there is a very very
good reason for it.

> page = alloc_pages_node(node, gfp, get_order(size));
> if (!page)
> return NULL;
> --
> 1.5.4.2
>
>

--
| AMD Saxony Limited Liability Company & Co. KG
Operating | Wilschdorfer Landstr. 101, 01109 Dresden, Germany
System | Register Court Dresden: HRA 4896
Research | General Partner authorized to represent:
Center | AMD Saxony LLC (Wilmington, Delaware, US)
| General Manager of AMD Saxony LLC: Dr. Hans-R. Deppe, Thomas McCoy