From 3d6cf29b3f117605c66583b9145f53d39c695a6e Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Mon, 7 Aug 2006 21:26:18 +0200 Subject: [PATCH] BLOCK: Fix bounce limit address check This fixes some OOMs on 64bit systems with <4GB of RAM when accessing the cdrom. Do a safer check for when to enable DMA. Currently we enable ISA DMA for cases that do not need it, resulting in OOM conditions when ZONE_DMA runs out of space. Signed-off-by: Andi Kleen Signed-off-by: Jens Axboe Signed-off-by: Adrian Bunk --- block/ll_rw_blk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index cd995c3fd5d9..1ce88cf8ff91 100644 --- a/block/ll_rw_blk.c +++ b/block/ll_rw_blk.c @@ -637,7 +637,7 @@ void blk_queue_bounce_limit(request_queue_t *q, u64 dma_addr) /* Assume anything <= 4GB can be handled by IOMMU. Actually some IOMMUs can handle everything, but I don't know of a way to test this here. */ - if (bounce_pfn < (0xffffffff>>PAGE_SHIFT)) + if (bounce_pfn < (min_t(u64,0xffffffff,BLK_BOUNCE_HIGH) >> PAGE_SHIFT)) dma = 1; q->bounce_pfn = max_low_pfn; #else