John Stultz wrote: Mozilla is starting to use android's ashmem for discardable memory within a single process: https://bugzilla.mozilla.org/show_bug.cgi?id=748598 .On 01/27/2014 04:12 PM, Minchan Kim wrote:On Mon, Jan 27, 2014 at 05:23:17PM -0500, KOSAKI Motohiro wrote:- Your number only claimed the effectiveness anon vrange, but not file vrange.Yes. It's really problem as I said. >From the beginning, John Stultz wanted to promote vrange-file to replace android's ashmem and when I heard usecase of vrange-file, it does make sense to me so that's why I'd like to unify them in a same interface. But the problem is lack of interesting from others and lack of time to test/evaluate it. I'm not an expert of userspace so actually I need a bit help from them who require the feature but at a moment, but I don't know who really want or/and help it. Even, Android folks didn't have any interest on vrange-file.Just as a correction here. I really don't think this is the case, as Android's use definitely relies on file based volatility. It might be more fair to say there hasn't been very much discussion from Android developers on the particulars of the file volatility semantics (out possibly not having any particular objections, or more-likely, being a bit too busy to follow the all various theoretical tangents we've discussed). But I'd not want anyone to get the impression that anonymous-only volatility would be sufficient for Android's needs. Volatile ranges do help with that specific(uncommon?) use of ashmem. For Mozilla sharing memory across processes via ashmem is not a nearterm project. It's something that is likely to require significant rework. Process-local discardable memory can be retrofited in a more straight-forward fashion. Taras |