On Tue, Mar 14, 2017 at 2:24 AM, Lars-Peter Clausen <lars@xxxxxxxxxx> wrote: > On 03/13/2017 09:51 PM, Jonathan Cameron wrote: > [...] >>>> Gargi, >>>> >>>> Please insert the new lock above the __cacheline_aligned struct >>>> member. >>> >>> I will do that, but is there any reason why the lock should be above >>> ____cacheline_aligned struct member? >> Yes. It's in fact very important that nothing comes after that. >> >> Will leave the why as an exercise for the reader. I'll give the >> hit of spi drivers that do DMA... > > > One hint though, the answer is somewhere in Documentation/DMA-API.txt >From what I have understood is that cacheline is used for keeping most frequently accessed values in adjacent cachelines. We want the cacheline_aligned at the end in the struct definition so as to avoid any holes after the cacheline boundary. > -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
