From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lin Feng Subject: [PATCH V2 0/2] mm: hotplug: implement non-movable version of get_user_pages() to kill long-time pin pages Date: Tue, 5 Feb 2013 17:21:51 +0800 Message-ID: <1360056113-14294-1-git-send-email-linfeng@cn.fujitsu.com> Cc: khlebnikov@openvz.org, walken@google.com, kamezawa.hiroyu@jp.fujitsu.com, minchan@kernel.org, riel@redhat.com, rientjes@google.com, isimatu.yasuaki@jp.fujitsu.com, wency@cn.fujitsu.com, laijs@cn.fujitsu.com, jiang.liu@huawei.com, zab@redhat.com, jmoyer@redhat.com, linux-mm@kvack.org, linux-aio@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Lin Feng To: akpm@linux-foundation.org, mgorman@suse.de, bcrl@kvack.org, viro@zeniv.linux.org.uk Return-path: Sender: owner-linux-aio@kvack.org List-Id: linux-fsdevel.vger.kernel.org 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 falls back to use the old version of get_user_pages(). --- ChangeLog v1->v2: Patch1: - Fix the negative return value bug pointed out by Andrew and other suggestions pointed out by Andrew and Jeff. Patch2: - Kill the CONFIG_MEMORY_HOTREMOVE dependence suggested by Jeff. --- Lin Feng (2): mm: hotplug: implement non-movable version of get_user_pages() called get_user_pages_non_movable() fs/aio.c: use get_user_pages_non_movable() to pin ring pages when support memory hotremove fs/aio.c | 4 +- include/linux/mm.h | 3 ++ include/linux/mmzone.h | 4 ++ mm/memory.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++ mm/page_isolation.c | 5 +++ 5 files changed, 97 insertions(+), 2 deletions(-) -- To unsubscribe, send a message with 'unsubscribe linux-aio' in the body to majordomo@kvack.org. For more info on Linux AIO, see: http://www.kvack.org/aio/ Don't email: aart@kvack.org