On 08/15/2012 05:22 PM, Mel Gorman wrote: >> I believe it >> > to be a better and less complicated approach then letting a page appear >> > and then charging it. Besides being consistent with the rest of memcg, >> > it won't create unnecessary disturbance in the page allocator >> > when the allocation is to fail. >> > > I still don't get why you did not just return a mem_cgroup instead of a > handle. > Forgot this one, sorry: The reason is to keep the semantics simple. What should we return if the code is not compiled in? If we return NULL for failure, the test becomes memcg = memcg_kmem_charge_page(gfp, order); if (!memcg) exit; If we're not compiled in, we'd either return positive garbage or we need to wrap it inside an ifdef I personally believe to be a lot more clear to standardize on true to mean "allocation can proceed". the compiled out case becomes: if (!true) exit; which is easily compiled away altogether. Now of course, using struct mem_cgroup makes sense, and I have already changed that here. -- 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>