Messages in this thread |  | | Subject | Re: [BK-2.5] Update the generic DMA API to take GFP_ flags on | Date | Tue, 14 Jan 2003 10:51:01 -0500 | From | James Bottomley <> |
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davem@redhat.com said: > Now what about the corollary, a platform that needs to sleep to setup > the cpu mapings in a race-free manner?
This one is the big bug bear. The DMA-mapping.txt doc says pci_alloc_consistent "may be called in interrupt context". Thus if the dma_alloc with GFP_ATOMIC uses the same code path, it should be safe. However, there are indications that pci_alloc_consistent wasn't interrupt safe on certain platforms (see other email re PA-RISC).
In any event, we're no worse off than we were with the pci_ API. Passing in the flags will hopefully allow us to create GFP_ATOMIC safe paths in the arch implementations which look iffy.
James
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