[PATCH 1/2] mtip32xx: Don't bounce IO requests

From: Felipe Franciosi
Date: Wed Mar 12 2014 - 12:08:35 EST


This device support 64-bit DMA and therefore no IO requests needs bouncing.
On 32-bit systems, blk_queue_bounce() will bounce all IO requests with high
mem pages. This makes performance really really bad.

Signed-off-by: Felipe Franciosi <felipe@xxxxxxxxxxxx>
---
drivers/block/mtip32xx/mtip32xx.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 5160269..24c87fdb 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -4082,8 +4082,6 @@ static void mtip_make_request(struct request_queue *queue, struct bio *bio)

sg = mtip_hw_get_scatterlist(dd, &tag, unaligned);
if (likely(sg != NULL)) {
- blk_queue_bounce(queue, &bio);
-
if (unlikely((bio)->bi_vcnt > MTIP_MAX_SG)) {
dev_warn(&dd->pdev->dev,
"Maximum number of SGL entries exceeded\n");
--
1.7.10.4

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