Messages in this thread | | | 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 |
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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(-)
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