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To: "Adam J. Richter" <adam@yggdrasil.com>
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Subject: Re: [PATCH] generic device DMA (dma_pool update) 
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adam@yggdrasil.com said:
> 	I thought Andrew Morton's request for a gfp flag was for allocating
> memory from a pool (for example, a "read ahead" will want to abort if
> memory is unavailable rather than wait).

Well, yes, but the underlying allocators will also have to take the flag too 
so that all the semantics are correct.


adam@yggdrasil.com said:
> 	Can someone show me or invent an example of two different uses of
> dma_alloc_coherent that really should use different policies on
> whether to block or not? 

The obvious one is allocations from interrupt routines, which must be 
GFP_ATOMIC (ignoring the issue of whether a driver should be doing a memory 
allocation in an interrupt).  Allocating large pools at driver initialisation 
should probably be GFP_KERNEL as you say.

James



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