Tejun Heo wrote: > I'm skeptical about the benefit of IRQ coalescing on storage > controllers. Coalescing improves performance when there are many small > requests to complete and if you put a lot of small non-consecutive > requests to a disk, it gets really really really slow and IRQ coalescing > just doesn't matter at all. The only way to achieve high number of > completions is to issue small commands to consecutive addresses which is > just silly. In storage, high volume transfer is achieved through > request coalescing not completion coalescing and this is true for even SDDs. To add a bit, I was thinking about writes regarding SDDs. Completion coalescing makes more sense for reads from SDDs if log based filesystem is used on it because then read operations are scattered all over the disk and the device doesn't have to seek. Limited queue size compared to network interfaces will make completion coalescing less effective but yeah, I think it will be worth playing with it on SDD + lfs. Thanks. -- tejun - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
