Currently get_user_pages() always tries to allocate pages from movable zone, as discussed in thread https://lkml.org/lkml/2012/11/29/69, in some case users of get_user_pages() is easy to pin user pages for a long time(for now we found that pages pinned as aio ring pages is such case), which is fatal for memory hotplug/remove framework. So the 1st patch introduces a new library function called get_user_pages_non_movable() to pin pages only from zone non-movable in memory. It's a wrapper of get_user_pages() but it makes sure that all pages come from non-movable zone via additional page migration. The 2nd patch gets around the aio ring pages can't be migrated bug caused by get_user_pages() via using the new function. It only works when configed with CONFIG_MEMORY_HOTREMOVE, otherwise it uses the old version of get_user_pages(). Lin Feng (2): mm: hotplug: implement non-movable version of get_user_pages() fs/aio.c: use non-movable version of get_user_pages() to pin ring pages when support memory hotremove fs/aio.c | 6 +++++ include/linux/mm.h | 5 ++++ include/linux/mmzone.h | 4 ++++ mm/memory.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++ mm/page_isolation.c | 5 ++++ 5 files changed, 83 insertions(+) -- 1.7.11.7 -- 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
