On Mon, 10 Oct 2011 16:24:03 -0700 Greg KH <greg@xxxxxxxxx> wrote: > On Mon, Oct 10, 2011 at 03:00:38PM -0700, Andrew Morton wrote: > > On Mon, 10 Oct 2011 08:11:19 +0100 > > Mel Gorman <mgorman@xxxxxxx> wrote: > > > > > It is expected that memory being brought online is PageReserved > > > similar to what happens when the page allocator is being brought up. > > > Memory is onlined in "memory blocks" which consist of one or more > > > sections. Unfortunately, the code that verifies PageReserved is > > > currently assuming that the memmap backing all these pages is virtually > > > contiguous which is only the case when CONFIG_SPARSEMEM_VMEMMAP is set. > > > As a result, memory hot-add is failing on !VMEMMAP configurations > > > with the message; > > > > > > kernel: section number XXX page number 256 not reserved, was it already online? > > > > > > This patch updates the PageReserved check to lookup struct page once > > > per section to guarantee the correct struct page is being checked. > > > > > > > Nathan's earlier version of this patch is already in linux-next, via > > Greg. We should drop the old version and get the new one merged > > instead. > > Ok, care to send me what exactly needs to be reverted and what needs to > be added? Drop commit 54f23eb7ba7619de85d8edca6e5336bc33072dbd Author: Nathan Fontenot <nfont@xxxxxxxxxxxxxx> Date: Mon Sep 26 10:22:33 2011 -0500 memory hotplug: Correct page reservation checking and replace it with start-of-this-thread. That's assuming that Mel's update passes Nathan's review and testing :) -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>