From 2b2b614dd24e4e6474fcf2dcf69c95c908838959 Mon Sep 17 00:00:00 2001 From: Zoltan Kiss Date: Wed, 4 Sep 2013 21:11:05 +0100 Subject: 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 [v1: Don't print 'swiotlb_force=X', just print swiotlb_force if it is enabled] Signed-off-by: Konrad Rzeszutek Wilk --- include/trace/events/swiotlb.h | 46 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 include/trace/events/swiotlb.h (limited to 'include/trace/events/swiotlb.h') 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 + +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 -- cgit v1.2.3