On 2011-08-11 15:33, Vivek Goyal wrote: > On Thu, Aug 11, 2011 at 09:42:16AM +0900, Kyungmin Park wrote: >> Hi Jens >> >> Now eMMC device requires the upper layer information to improve the data >> performance and reliability. >> >> . Context ID >> Using the context information, it can sort out the data internally and improve the performance. >> The main problem is that it's needed to define "What's the context". >> Actually I expect cfq queue has own unique ID but it doesn't so decide to use the pid instead >> > > Hi, > > Can you please give little more details about the optimization you will > do with this pid information? It is provided in one of the other email threads for this patch. > Also what happens in the case of noop and deadline which don't maintain > per process queues and can't provide this information. It'll still work, it isn't really tied to the CFQ way of diviying things up. >> First I expect the REQ_META but current ext4 doesn't pass the WRITE_META. only use the READ_META. so it needs to investigate it. > > So are you planning to later fix file systems to appropriately mark meta > data requests? One thing that occured to me is that equating META to HOT is not necessarily a good idea. Meta data isn't necessarily more "hot" than regular data, it all depends on how it's being used. So I think it would be a lot more appropriate to pass down this information specifically, instead of overloading REQ_META. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
