Messages in this thread | | | Subject | Re: SCSI breakage on non-cache coherent architectures | From | Benjamin Herrenschmidt <> | Date | Tue, 20 Nov 2007 11:34:24 +1100 |
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On Mon, 2007-11-19 at 14:31 -0800, David Miller wrote: > From: Benjamin Herrenschmidt <benh@kernel.crashing.org> > Date: Tue, 20 Nov 2007 06:51:14 +1100 > > > On Mon, 2007-11-19 at 00:38 -0800, David Miller wrote: > > > From: Benjamin Herrenschmidt <benh@kernel.crashing.org> > > > Date: Mon, 19 Nov 2007 16:35:23 +1100 > > > > > > You could make a ____dma_cacheline_aligned and use that. > > > It seems pretty reasonable. > > > > I was thinking about that. What archs would need it ? arm, mips, what > > else ? > > The sparc32 port would need it too.
James preference seem to go for a revert of the patch that removed the kmalloc of the buffer instead. Sounds definitely like an easier plan for .24 (and maybe even backport to stable).
I'll produce a patch for that later today or tomorrow.
Do you still think we should introduce this __dma_cacheline_aligned ? Do you see other cases of drivers where it would be useful ? It tend to agree with your earlier statement that drivers doing that are broken and should be using a separate allocator for DMA'ble objects (in fact, on non-cache coherent archs, kmalloc is just fine).
Cheers, Ben.
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