linux/mm/memory_hotplug.c, branch v3.2.38

memory hotplug: fix section info double registration bug

2012-10-10T02:30:47Z

commit f14851af0ebb32745c6c5a2e400aa0549f9d20df upstream. There may be a bug when registering section info. For example, on my Itanium platform, the pfn range of node0 includes the other nodes, so other nodes' section info will be double registered, and memmap's page count will equal to 3. node0: start_pfn=0x100, spanned_pfn=0x20fb00, present_pfn=0x7f8a3, => 0x000100-0x20fc00 node1: start_pfn=0x80000, spanned_pfn=0x80000, present_pfn=0x80000, => 0x080000-0x100000 node2: start_pfn=0x100000, spanned_pfn=0x80000, present_pfn=0x80000, => 0x100000-0x180000 node3: start_pfn=0x180000, spanned_pfn=0x80000, present_pfn=0x80000, => 0x180000-0x200000 free_all_bootmem_node() register_page_bootmem_info_node() register_page_bootmem_info_section() When hot remove memory, we can't free the memmap's page because page_count() is 2 after put_page_bootmem(). sparse_remove_one_section() free_section_usemap() free_map_bootmem() put_page_bootmem() [akpm@linux-foundation.org: add code comment] Signed-off-by: Xishi Qiu Signed-off-by: Jiang Liu Acked-by: Mel Gorman Cc: "Luck, Tony" Cc: Yasuaki Ishimatsu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings

mm: compaction: introduce sync-light migration for use by compaction

2012-08-02T13:37:32Z

commit a6bc32b899223a877f595ef9ddc1e89ead5072b8 upstream. Stable note: Not tracked in Buzilla. This was part of a series that reduced interactivity stalls experienced when THP was enabled. These stalls were particularly noticable when copying data to a USB stick but the experiences for users varied a lot. This patch adds a lightweight sync migrate operation MIGRATE_SYNC_LIGHT mode that avoids writing back pages to backing storage. Async compaction maps to MIGRATE_ASYNC while sync compaction maps to MIGRATE_SYNC_LIGHT. For other migrate_pages users such as memory hotplug, MIGRATE_SYNC is used. This avoids sync compaction stalling for an excessive length of time, particularly when copying files to a USB stick where there might be a large number of dirty pages backed by a filesystem that does not support ->writepages. [aarcange@redhat.com: This patch is heavily based on Andrea's work] [akpm@linux-foundation.org: fix fs/nfs/write.c build] [akpm@linux-foundation.org: fix fs/btrfs/disk-io.c build] Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel Cc: Andrea Arcangeli Cc: Minchan Kim Cc: Dave Jones Cc: Jan Kara Cc: Andy Isaacson Cc: Nai Xia Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings

mm: Map most files to use export.h instead of module.h

2011-10-31T13:20:12Z

The files changed within are only using the EXPORT_SYMBOL macro variants. They are not using core modular infrastructure and hence don't need module.h but only the export.h header. Signed-off-by: Paul Gortmaker

mm: extend memory hotplug API to allow memory hotplug in virtual machines

2011-07-26T03:57:08Z

This patch contains online_page_callback and apropriate functions for registering/unregistering online page callbacks. It allows to do some machine specific tasks during online page stage which is required to implement memory hotplug in virtual machines. Currently this patch is required by latest memory hotplug support for Xen balloon driver patch which will be posted soon. Additionally, originial online_page() function was splited into following functions doing "atomic" operations: - __online_page_set_limits() - set new limits for memory management code, - __online_page_increment_counters() - increment totalram_pages and totalhigh_pages, - __online_page_free() - free page to allocator. It was done to: - not duplicate existing code, - ease hotplug code devolpment by usage of well defined interface, - avoid stupid bugs which are unavoidable when the same code (by design) is developed in many places. [akpm@linux-foundation.org: use explicit indirect-call syntax] Signed-off-by: Daniel Kiper Reviewed-by: Konrad Rzeszutek Wilk Cc: Ian Campbell Cc: Jeremy Fitzhardinge Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm, hotplug: protect zonelist building with zonelists_mutex

2011-06-23T04:06:48Z

Commit 959ecc48fc75 ("mm/memory_hotplug.c: fix building of node hotplug zonelist") does not protect the build_all_zonelists() call with zonelists_mutex as needed. This can lead to races in constructing zonelist ordering if a concurrent build is underway. Protecting this with lock_memory_hotplug() is insufficient since zonelists can be rebuild though sysfs as well. Signed-off-by: David Rientjes Reviewed-by: KOSAKI Motohiro Signed-off-by: Linus Torvalds

mm, hotplug: fix error handling in mem_online_node()

2011-06-23T04:06:47Z

The error handling in mem_online_node() is incorrect: hotadd_new_pgdat() returns NULL if the new pgdat could not have been allocated and a pointer to it otherwise. mem_online_node() should fail if hotadd_new_pgdat() fails, not the inverse. This fixes an issue when memoryless nodes are not onlined and their sysfs interface is not registered when their first cpu is brought up. The bug was introduced by commit cf23422b9d76 ("cpu/mem hotplug: enable CPUs online before local memory online") iow v2.6.35. Signed-off-by: David Rientjes Reviewed-by: KOSAKI Motohiro Cc: stable@kernel.org Signed-off-by: Linus Torvalds

mm/memory_hotplug.c: fix building of node hotplug zonelist

2011-06-16T03:04:01Z

During memory hotplug we refresh zonelists when we online a page in a new zone. It means that the node's zonelist is not initialized until pages are onlined. So for example, "nid" passed by MEM_GOING_ONLINE notifier will point to NODE_DATA(nid) which has no zone fallback list. Moreover, if we hot-add cpu-only nodes, alloc_pages() will do no fallback. This patch makes a zonelist when a new pgdata is available. Note: in production, at fujitsu, memory should be onlined before cpu and our server didn't have any memory-less nodes and had no problems. But recent changes in MEM_GOING_ONLINE+page_cgroup will access not initialized zonelist of node. Anyway, there are memory-less node and we need some care. Signed-off-by: KAMEZAWA Hiroyuki Cc: Mel Gorman Cc: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: remove dependency on CONFIG_FLATMEM from online_page()

2011-05-25T15:39:28Z

online_pages() is only compiled for CONFIG_MEMORY_HOTPLUG_SPARSE, so there is no need to support CONFIG_FLATMEM code within it. This patch removes code that is never used. Signed-off-by: Daniel Kiper Acked-by: Dave Hansen Acked-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mem-hotplug: call isolate_lru_page with elevated refcount

2011-05-25T15:39:22Z

isolate_lru_page() must be called only with stable reference to page. So, let's grab normal page reference. Signed-off-by: Konstantin Khlebnikov Cc: Andi Kleen Cc: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro Cc: Mel Gorman Cc: Lee Schermerhorn Cc: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm, mem-hotplug: recalculate lowmem_reserve when memory hotplug occurs

2011-05-25T15:39:09Z

Currently, memory hotplug calls setup_per_zone_wmarks() and calculate_zone_inactive_ratio(), but doesn't call setup_per_zone_lowmem_reserve(). It means the number of reserved pages aren't updated even if memory hot plug occur. This patch fixes it. Signed-off-by: KOSAKI Motohiro Reviewed-by: KAMEZAWA Hiroyuki Acked-by: Mel Gorman Reviewed-by: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds