[PATCH 2.6.19] Adding branch to remove possible unnecessary inst

From: yc_zhou
Date: Sun Dec 31 2006 - 01:27:55 EST


Function blk_queue_bounce_limit using dma flag to determine whether
assigned a certain value for member of request_queue_t. But the
assignment is unconditionally after the flag is set. It introduce
possible unnecessary instructions.


Signed-Off-By: Yingchao Zhou <yc_zhou@xxxxxxxxxx>

---
--- linux-2.6.19/block/ll_rw_blk.c.orig 2006-12-31 13:35:22.307742904 +0800
+++ linux-2.6.19/block/ll_rw_blk.c 2006-12-31 13:34:05.032490528 +0800
@@ -606,11 +606,13 @@ void blk_queue_bounce_limit(request_queu
know of a way to test this here. */
if (bounce_pfn < (min_t(u64,0xffffffff,BLK_BOUNCE_HIGH) >> PAGE_SHIFT))
dma = 1;
- q->bounce_pfn = max_low_pfn;
+ else
+ q->bounce_pfn = max_low_pfn;
#else
if (bounce_pfn < blk_max_low_pfn)
dma = 1;
- q->bounce_pfn = bounce_pfn;
+ else
+ q->bounce_pfn = bounce_pfn;
#endif
if (dma) {
init_emergency_isa_pool();

-
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