[PATCH v2] ARM: mm: Do not invoke OOM for higher order IOMMU DMA allocations

[Doug Anderson]

Tomasz,

On Mon, Mar 23, 2015 at 12:27 AM, Tomasz Figa <tfiga at chromium.org> wrote:
> IOMMU should be able to use single pages as well as bigger blocks, so if
> higher order allocations fail, we should not affect state of the system,
> with events such as OOM killer, but rather fall back to order 0
> allocations.
>
> This patch changes the behavior of ARM IOMMU DMA allocator to use
> __GFP_NORETRY, which bypasses OOM invocation, for orders higher than
> zero and, only if that fails, fall back to normal order 0 allocation
> which might invoke OOM killer.
>
> Signed-off-by: Tomasz Figa <tfiga at chromium.org>
> ---
>  arch/arm/mm/dma-mapping.c | 27 +++++++++++++++++++++------
>  1 file changed, 21 insertions(+), 6 deletions(-)

FWIW:

Reviewed-by: Doug Anderson <dianders at chromium.org>