From: Andi Kleen Date: Mon, 7 Aug 2006 19:26:18 +0000 (+0200) Subject: BLOCK: Fix bounce limit address check X-Git-Tag: v2.6.16.28-rc1~11 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3d6cf29b3f117605c66583b9145f53d39c695a6e;p=thirdparty%2Fkernel%2Fstable.git 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 --- diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index cd995c3fd5d96..1ce88cf8ff91c 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