Commit 292a8942 authored Jan 02, 2019 by Vinayak Menon Committed by Gerrit - the friendly Code Review server May 02, 2019

iommu: do not attempt reclaim on higher order allocs



Attempting reclaim for non-zero order allocations can result in
the context blocked in reclaim for unpredictable amounts of time.
There are cases reported where dma_alloc_attrs gets blocked for
20+ seconds for an allocation of 200MB. Since higher order
allocation is not a necessity in the presence of iommu, avoid
reclaim.

Change-Id: I93f57e2ea5f7c57ec84a92911e2aae36112d95e1
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>

parent 71ba584c

drivers/iommu/dma-iommu.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -475,8 +475,9 @@ static struct page **__iommu_dma_alloc_pages(unsigned int count,
		unsigned int order = __fls(order_mask);

		order_size = 1U << order;
		page = alloc_pages((order_mask - order_size) ?
		gfp \| __GFP_NORETRY : gfp, order);
		page = alloc_pages(order ?
		(gfp \| __GFP_NORETRY) &
		~__GFP_RECLAIM : gfp, order);
		if (!page)
		continue;
		if (!order)