On Thu, 2010-08-26 at 04:40 +0200, Michał Nazarewicz wrote: > I think that the biggest problem is fragmentation here. For instance, > I think that a situation where there is enough free space but it's > fragmented so no single contiguous chunk can be allocated is a serious > problem. However, I would argue that if there's simply no space left, > a multimedia device could fail and even though it's not desirable, it > would not be such a big issue in my eyes. > > So, if only movable or discardable pages are allocated in CMA managed > regions all should work well. When a device needs memory discardable > pages would get freed and movable moved unless there is no space left > on the device in which case allocation would fail.
If you'd actually looked at the page allocator you'd see its capable of doing exactly that! I has the notion of movable pages, it can defragment free space (called compaction). Use it! -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
