Hi YingHang, > Actually I've talked about it with Fengguang, he advised we should unify the > ra_pages in struct bdi and file_ra_state and leave the issue that > spreading data > across disks as it is. > Fengguang, what's you opinion about this? Yeah the two ra_pages may run out of sync for already opened files, which could be a problem for long opened files. However as Dave put it, a device's max readahead size is typically a static value that can be set at mount time. So, the question is: do you really hurt from the old behavior that deserves this code change? I agree with Dave that the multi-disk case is not a valid concern. In fact, how can the patch help that case? I mean, if it's two fuse files lying in two disks, it *was* not a problem at all. If it's one big file spreading to two disks, it's a too complex scheme to be practically manageable which I doubt if you have such a setup. Thanks, Fengguang -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>