Messages in this thread | | | Date | Fri, 10 Jun 2011 10:12:33 +0100 | From | Russell King - ARM Linux <> | Subject | Re: [PATCH] Make GFP_DMA allocations w/o ZONE_DMA emit a warning instead of failing |
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On Fri, Jun 10, 2011 at 12:11:42PM +0400, Dmitry Eremin-Solenikov wrote: > On 6/10/11, Andrew Morton <akpm@linux-foundation.org> wrote: > > On Fri, 10 Jun 2011 16:38:06 +0900 KOSAKI Motohiro > > <kosaki.motohiro@jp.fujitsu.com> wrote: > > > >> Subject: [PATCH] Revert "mm: fail GFP_DMA allocations when ZONE_DMA is not > >> configured" > > > > Confused. We reverted this over a week ago. > > Should one submit a patch adding a warning to GFP_DMA allocations > w/o ZONE_DMA, or the idea of the original patch is wrong?
Linus was far from impressed by the original commit, saying: | Using GFP_DMA is reasonable in a driver - on platforms where that | matters, it should allocate from the DMA zone, on platforms where it | doesn't matter it should be a no-op.
So no, not even a warning.
What is a useful exercise though is to remove GFP_DMA from those allocations which should never have had GFP_DMA added - such as those used for data structures which have nothing to do with DMA at all. Also dma_alloc_coherent() should not be given GFP_DMA in any case.
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