Commit efb012b3 authored Oct 01, 2010 by Malahal Naineni Committed by Jens Axboe Oct 01, 2010

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 <malahal@us.ibm.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

parent 260a67a9

block/blk-settings.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -214,7 +214,7 @@ 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;
		q->limits.bounce_pfn = max(max_low_pfn, b_pfn);
		#else
		if (b_pfn < blk_max_low_pfn)
		dma = 1;