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authorZoltan Kiss <zoltan.kiss@citrix.com>2013-09-05 00:11:05 +0400
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2013-10-02 20:53:26 +0400
commit2b2b614dd24e4e6474fcf2dcf69c95c908838959 (patch)
tree9874899c477d237e1ec207834fc730c1151088f5 /include/trace
parent04b772d2b819f0dda2163e3193fa7cd447a6245c (diff)
downloadlinux-2b2b614dd24e4e6474fcf2dcf69c95c908838959.tar.xz
tracing/events: Add bounce tracing to swiotbl
Ftrace is currently not able to detect when SWIOTLB has to do double buffering. Under Xen you can only see it indirectly in function_graph, when xen_swiotlb_map_page() doesn't stop after range_straddles_page_boundary(), but calls spinlock functions, memcpy() and xen_phys_to_bus() as well. This patch introduces the swiotlb:swiotlb_bounced event, which also prints out the following informations to help you find out why bouncing happened: dev_name: 0000:08:00.0 dma_mask=ffffffffffffffff dev_addr=9149f000 size=32768 swiotlb_force=0 If you use Xen, and (dev_addr + size + 1) > dma_mask, the buffer is out of the device's DMA range. If swiotlb_force == 1, you should really change the kernel parameters. Otherwise, the buffer is not contiguous in mfn space. Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> [v1: Don't print 'swiotlb_force=X', just print swiotlb_force if it is enabled] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'include/trace')
-rw-r--r--include/trace/events/swiotlb.h46
1 files changed, 46 insertions, 0 deletions
diff --git a/include/trace/events/swiotlb.h b/include/trace/events/swiotlb.h
new file mode 100644
index 000000000000..7ea4c5e7c448
--- /dev/null
+++ b/include/trace/events/swiotlb.h
@@ -0,0 +1,46 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM swiotlb
+
+#if !defined(_TRACE_SWIOTLB_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_SWIOTLB_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(swiotlb_bounced,
+
+ TP_PROTO(struct device *dev,
+ dma_addr_t dev_addr,
+ size_t size,
+ int swiotlb_force),
+
+ TP_ARGS(dev, dev_addr, size, swiotlb_force),
+
+ TP_STRUCT__entry(
+ __string( dev_name, dev_name(dev) )
+ __field( u64, dma_mask )
+ __field( dma_addr_t, dev_addr )
+ __field( size_t, size )
+ __field( int, swiotlb_force )
+ ),
+
+ TP_fast_assign(
+ __assign_str(dev_name, dev_name(dev));
+ __entry->dma_mask = (dev->dma_mask ? *dev->dma_mask : 0);
+ __entry->dev_addr = dev_addr;
+ __entry->size = size;
+ __entry->swiotlb_force = swiotlb_force;
+ ),
+
+ TP_printk("dev_name: %s dma_mask=%llx dev_addr=%llx "
+ "size=%zu %s",
+ __get_str(dev_name),
+ __entry->dma_mask,
+ (unsigned long long)__entry->dev_addr,
+ __entry->size,
+ __entry->swiotlb_force ? "swiotlb_force" : "" )
+);
+
+#endif /* _TRACE_SWIOTLB_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>