Messages in this thread Patch in this message |  | | From | Arnd Bergmann <> | Subject | Re: [PATCH v2] mm: dmapool: use provided gfp flags for all dma_alloc_coherent() calls | Date | Thu, 17 Jan 2013 20:26:45 +0000 |
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On Thursday 17 January 2013, Soeren Moch wrote: > On 17.01.2013 11:49, Arnd Bergmann wrote: > > On Wednesday 16 January 2013, Soeren Moch wrote: > >>>> I will see what I can do here. Is there an easy way to track the buffer > >>>> usage without having to wait for complete exhaustion? > >>> > >>> DMA_API_DEBUG > >> > >> OK, maybe I can try this. > >>> > > > > Any success with this? It should at least tell you if there is a > > memory leak in one of the drivers. > > Not yet, sorry. I have to do all the tests in my limited spare time. > Can you tell me what to search for in the debug output?
Actually now that I've looked closer, you can't immediately see all the mappings as I thought.
But please try enabling DMA_API_DEBUG in combination with this one-line patch:
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 6b2fb87..3df74ac 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -497,6 +497,7 @@ static void *__alloc_from_pool(size_t size, struct page **ret_page) pr_err_once("ERROR: %u KiB atomic DMA coherent pool is too small!\n" "Please increase it with coherent_pool= kernel parameter!\n", (unsigned)pool->size / 1024); + debug_dma_dump_mappings(NULL); } spin_unlock_irqrestore(&pool->lock, flags); That will show every single allocation that is currently active. This lets you see where all the memory went, and if there is a possible leak or excessive fragmentation. Arnd
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