linux/mm/memory_hotplug.c, branch v2.6.37

mem-hotplug: introduce {un}lock_memory_hotplug()

2010-12-02T22:51:15Z

Presently hwpoison is using lock_system_sleep() to prevent a race with memory hotplug. However lock_system_sleep() is a no-op if CONFIG_HIBERNATION=n. Therefore we need a new lock. Signed-off-by: KOSAKI Motohiro Cc: Andi Kleen Cc: Kamezawa Hiroyuki Suggested-by: Hugh Dickins Acked-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: do_migrate_range: reduce list_empty() check

2010-10-26T23:52:11Z

Simple code for reducing list_empty(&source) check. Signed-off-by: Bob Liu Acked-by: KAMEZAWA Hiroyuki Acked-by: Wu Fengguang Cc: KOSAKI Motohiro Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: do_migrate_range: exit loop if not_managed is true

2010-10-26T23:52:11Z

If not_managed is true all pages will be putback to lru, so break the loop earlier to skip other pages isolate. Signed-off-by: Bob Liu Acked-by: KAMEZAWA Hiroyuki Acked-by: Wu Fengguang Cc: KOSAKI Motohiro Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/memory_hotplug.c: make scan_lru_pages() static

2010-10-26T23:52:10Z

Reported-by: KOSAKI Motohiro Cc: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memory hotplug: unify is_removable and offline detection code

2010-10-26T23:52:06Z

Now, sysfs interface of memory hotplug shows whether the section is removable or not. But it checks only migrateype of pages and doesn't check details of cluster of pages. Next, memory hotplug's set_migratetype_isolate() has the same kind of check, too. This patch adds the function __count_unmovable_pages() and makes above 2 checks to use the same logic. Then, is_removable and hotremove code uses the same logic. No changes in the hotremove logic itself. TODO: need to find a way to check RECLAMABLE. But, considering bit, calling shrink_slab() against a range before starting memory hotremove sounds better. If so, this patch's logic doesn't need to be changed. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: KAMEZAWA Hiroyuki Reported-by: Michal Hocko Cc: Wu Fengguang Cc: Mel Gorman Cc: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: compaction: fix COMPACTPAGEFAILED counting

2010-10-26T23:52:06Z

Presently update_nr_listpages() doesn't have a role. That's because lists passed is always empty just after calling migrate_pages. The migrate_pages cleans up page list which have failed to migrate before returning by aaa994b3. [PATCH] page migration: handle freeing of pages in migrate_pages() Do not leave pages on the lists passed to migrate_pages(). Seems that we will not need any postprocessing of pages. This will simplify the handling of pages by the callers of migrate_pages(). At that time, we thought we don't need any postprocessing of pages. But the situation is changed. The compaction need to know the number of failed to migrate for COMPACTPAGEFAILED stat This patch makes new rule for caller of migrate_pages to call putback_lru_pages. So caller need to clean up the lists so it has a chance to postprocess the pages. [suggested by Christoph Lameter] Signed-off-by: Minchan Kim Cc: Hugh Dickins Cc: Andi Kleen Reviewed-by: Mel Gorman Reviewed-by: Wu Fengguang Acked-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: fix return value of scan_lru_pages in memory unplug

2010-10-26T23:52:03Z

scan_lru_pages returns pfn. So, it's type should be "unsigned long" not "int". Note: I guess this has been work until now because memory hotplug tester's machine has not very big memory.... physical address < 32bit << PAGE_SHIFT. Reported-by: KOSAKI Motohiro Signed-off-by: KAMEZAWA Hiroyuki Reviewed-by: KOSAKI Motohiro Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memory_hotplug: drop spurious calls to flush_scheduled_work()

2010-10-19T09:08:41Z

lru_add_drain_all() uses schedule_on_each_cpu() which is synchronous. There is no reason to call flush_scheduled_work() after lru_add_drain_all(). Drop the spurious calls. This is to prepare for the deprecation and removal of flush_scheduled_work(). Signed-off-by: Tejun Heo Acked-by: KAMEZAWA Hiroyuki Reviewed-by: Minchan Kim Acked-by: Mel Gorman

memory hotplug: fix next block calculation in is_removable

2010-09-10T01:57:24Z

next_active_pageblock() is for finding next _used_ freeblock. It skips several blocks when it finds there are a chunk of free pages lager than pageblock. But it has 2 bugs. 1. We have no lock. page_order(page) - pageblock_order can be minus. 2. pageblocks_stride += is wrong. it should skip page_order(p) of pages. Signed-off-by: KAMEZAWA Hiroyuki Cc: Michal Hocko Cc: Wu Fengguang Cc: Mel Gorman Cc: KAMEZAWA Hiroyuki Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mem-hotplug: fix potential race while building zonelist for new populated zone

2010-05-25T15:07:02Z

Add global mutex zonelists_mutex to fix the possible race: CPU0 CPU1 CPU2 (1) zone->present_pages += online_pages; (2) build_all_zonelists(); (3) alloc_page(); (4) free_page(); (5) build_all_zonelists(); (6) __build_all_zonelists(); (7) zone->pageset = alloc_percpu(); In step (3,4), zone->pageset still points to boot_pageset, so bad things may happen if 2+ nodes are in this state. Even if only 1 node is accessing the boot_pageset, (3) may still consume too much memory to fail the memory allocations in step (7). Besides, atomic operation ensures alloc_percpu() in step (7) will never fail since there is a new fresh memory block added in step(6). [haicheng.li@linux.intel.com: hold zonelists_mutex when build_all_zonelists] Signed-off-by: Haicheng Li Signed-off-by: Wu Fengguang Reviewed-by: Andi Kleen Cc: Christoph Lameter Cc: Mel Gorman Cc: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds