[PATCH] swiotlb: add kernel error message to track iobtlb overflowbuffer usage

From: Shuah Khan
Date: Fri Aug 31 2012 - 20:55:57 EST


Add kernel error message to track iotlb overflow buffer triggers to understand
how often the overflow buffer gets used.

Signed-off-by: Shuah Khan <shuah.khan@xxxxxx>
---
lib/swiotlb.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 45bc1f8..597d7b9 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -682,6 +682,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
if (!map) {
swiotlb_full(dev, size, dir, 1);
map = io_tlb_overflow_buffer;
+ dev_err(dev, "SWIOTLB is full. Mapping overflow buffer.\n");
}

dev_addr = swiotlb_virt_to_bus(dev, map);
--
1.7.9.5



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