Messages in this thread | | | Date | Mon, 26 Jan 2015 12:54:08 +0100 | From | Joerg Roedel <> | Subject | Re: [PATCH 2/3] x86, swiotlb: Try coherent allocations with __GFP_NOWARN |
| |
On Mon, Jan 26, 2015 at 11:22:36AM +0800, Baoquan He wrote: > > Ok, so this practically does all allocations __GFP_NOWARN now. Shouldn't > > you be doing this before swiotlb_alloc_coherent() and not before > > dma_generic_alloc_coherent()? > > I think this patch mainly suppress warning from buddy allocation > failure because it tried buddy allocation several times before the final > try of bounce buffer allocation. Buddy allocation failure will call > dump_stack.
Yes, exactly. The default low-memory available to the page-allocator with crashkernel=high is 8MB. This is up pretty fast and then we start to get warnings, even when there is still memory left in the swiotlb space. The __GFP_WARN is there to suppress the warnings from the page-allocator, so it has to be set before it is called.
Joerg
| |