Re: [PATCH] drivers: cma: don't fail if migration returns -EAGAIN

From: Minchan Kim
Date: Thu May 10 2012 - 11:14:37 EST


On Thu, May 10, 2012 at 03:19:35PM +0200, Marek Szyprowski wrote:
> alloc_contig_range() function might return -EAGAIN if migrate_pages() call

migrate_page never return -EAGAIN and I can't find any -EAGAIN return in alloc_contig_range.
Am I seeing different tree?

> fails for some temporarily locked pages. Such case should not be fatal
> to dma_alloc_from_contiguous(), which should retry allocation like in case
> of -EBUSY error.
>
> Reported-by: Haojian Zhuang <haojian.zhuang@xxxxxxxxx>
> Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> ---
> drivers/base/dma-contiguous.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
> index 78efb03..e46e2fb 100644
> --- a/drivers/base/dma-contiguous.c
> +++ b/drivers/base/dma-contiguous.c
> @@ -346,7 +346,7 @@ struct page *dma_alloc_from_contiguous(struct device *dev, int count,
> if (ret == 0) {
> bitmap_set(cma->bitmap, pageno, count);
> break;
> - } else if (ret != -EBUSY) {
> + } else if (ret != -EBUSY && ret != -EAGAIN) {
> goto error;
> }
> pr_debug("%s(): memory range at %p is busy, retrying\n",
> --
> 1.7.1.569.g6f426
>
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