On Wed, 12 May 2010 00:35:45 -0400 Mike Frysinger <vapier.adi@xxxxxxxxx> wrote: > On Tue, May 11, 2010 at 23:23, FUJITA Tomonori wrote: > > Seems that kmalloc is not cacheline aligned on some architectures but > > they works. Probably, we might be just lucky because in general they > > allocate larger buffers than 64 for DMA via kmalloc and the buffers > > are aligned on the size? > > i think the magic combo is: > - DMA buffer is written to (receive) > - some driver state is in the same cacheline as the DMA buffer > - that driver state is used after the flush but before the DMA finishes > - only on arches that need software cache coherency > > so i could see this not being an obvious issue for many people Yeah, we don't hit such condition everyday. And as I said, SCSI usually uses kmalloc'ed buffers rather than the cache size (buffers are aligned on roundup_pow_of_two(the allocated size)). But I think that we want to fix this issue explicitly. I guess that it would be better to start a new thread about this issue. -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
