diff options
| -rw-r--r-- | arch/arm/mm/dma-mapping.c | 34 |
1 files changed, 20 insertions, 14 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 0eca3812527e..bc9cebfa0891 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1122,6 +1122,9 @@ static inline void __free_iova(struct dma_iommu_mapping *mapping, spin_unlock_irqrestore(&mapping->lock, flags); } +/* We'll try 2M, 1M, 64K, and finally 4K; array must end with 0! */ +static const int iommu_order_array[] = { 9, 8, 4, 0 }; + static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, gfp_t gfp, struct dma_attrs *attrs) { @@ -1129,6 +1132,7 @@ static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, int count = size >> PAGE_SHIFT; int array_size = count * sizeof(struct page *); int i = 0; + int order_idx = 0; if (array_size <= PAGE_SIZE) pages = kzalloc(array_size, GFP_KERNEL); @@ -1162,22 +1166,24 @@ static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, while (count) { int j, order; - for (order = __fls(count); order > 0; --order) { - /* - * We do not want OOM killer to be invoked as long - * as we can fall back to single pages, so we force - * __GFP_NORETRY for orders higher than zero. - */ - pages[i] = alloc_pages(gfp | __GFP_NORETRY, order); - if (pages[i]) - break; + order = iommu_order_array[order_idx]; + + /* Drop down when we get small */ + if (__fls(count) < order) { + order_idx++; + continue; } - if (!pages[i]) { - /* - * Fall back to single page allocation. - * Might invoke OOM killer as last resort. - */ + if (order) { + /* See if it's easy to allocate a high-order chunk */ + pages[i] = alloc_pages(gfp | __GFP_NORETRY, order); + + /* Go down a notch at first sign of pressure */ + if (!pages[i]) { + order_idx++; + continue; + } + } else { pages[i] = alloc_pages(gfp, 0); if (!pages[i]) goto error; |