On Thu, 2011-08-18 at 21:13 +0800, Wu Fengguang wrote: > Thinking twice about it, I find that the different requirements for > interval flash/external microSD can also be solved by this scheme. > > Introduce a per-bdi dirty_background_time (and optionally dirty_time) > as the counterpart of (and works in parallel to) global dirty[_background]_ratio, > however with unit "milliseconds worth of data". > > The per-bdi dirty_background_time will be set low for external microSD > and high for internal flash. Then you get timely writeouts for microSD > and reasonably delayed writes for internal flash (controllable by the > global dirty_expire_centisecs). > > The dirty_background_time will actually work more reliable than > dirty_expire_centisecs because it will checked immediately after the > application dirties more pages. And the dirty_time could provide > strong data integrity guarantee -- much stronger than > dirty_expire_centisecs -- if used. > > Does that sound reasonable? Yes, this would probably work. But note, we do not have this problem anymore, I was just talking about the past experience, so I cannot validate any possible patch. Thanks. -- Best Regards, Artem Bityutskiy -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
