From c49825facfd4969585224a896a5e717f88450cad Mon Sep 17 00:00:00 2001 From: Malahal Naineni Date: Fri, 24 Sep 2010 20:25:49 +0200 Subject: [PATCH] block: set the bounce_pfn to the actual DMA limit rather than to max memory The bounce_pfn of the request queue in 64 bit systems is set to the current max_low_pfn. Adding more memory later makes this incorrect. Memory allocated beyond this boot time max_low_pfn appear to require bounce buffers (bounce buffers are actually not allocated but used in calculating segments that may result in "over max segments limit" errors). Signed-off-by: Malahal Naineni Signed-off-by: Jens Axboe --- block/blk-settings.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/block/blk-settings.c b/block/blk-settings.c index f8f2ddf20613..f47af5031eaa 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -214,16 +214,14 @@ void blk_queue_bounce_limit(struct request_queue *q, u64 dma_mask) */ if (b_pfn < (min_t(u64, 0xffffffffUL, BLK_BOUNCE_HIGH) >> PAGE_SHIFT)) dma = 1; - q->limits.bounce_pfn = max_low_pfn; #else if (b_pfn < blk_max_low_pfn) dma = 1; - q->limits.bounce_pfn = b_pfn; #endif + q->limits.bounce_pfn = b_pfn; if (dma) { init_emergency_isa_pool(); q->bounce_gfp = GFP_NOIO | GFP_DMA; - q->limits.bounce_pfn = b_pfn; } } EXPORT_SYMBOL(blk_queue_bounce_limit); -- 2.20.1