kernel.git/mm/mempolicy.c, branch linux-3.11.y

mm: mempolicy: fix mbind_range() && vma_adjust() interaction

2013-07-31T21:41:02Z

vma_adjust() does vma_set_policy(vma, vma_policy(next)) and this is doubly wrong: 1. This leaks vma->vm_policy if it is not NULL and not equal to next->vm_policy. This can happen if vma_merge() expands "area", not prev (case 8). 2. This sets the wrong policy if vma_merge() joins prev and area, area is the vma the caller needs to update and it still has the old policy. Revert commit 1444f92c8498 ("mm: merging memory blocks resets mempolicy") which introduced these problems. Change mbind_range() to recheck mpol_equal() after vma_merge() to fix the problem that commit tried to address. Signed-off-by: Oleg Nesterov Acked-by: KOSAKI Motohiro Cc: Steven T Hampson Cc: Mel Gorman Cc: KOSAKI Motohiro Cc: Rik van Riel Cc: Andi Kleen Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/mempolicy.c: fix sp_node_init() argument ordering

2013-03-08T23:05:34Z

Currently, n_new is wrongly initialized. start and end parameter are inverted. Let's fix it. Signed-off-by: KOSAKI Motohiro Cc: Hillf Danton Cc: Sasha Levin Cc: Hugh Dickins Cc: Mel Gorman Cc: Dave Jones Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/mempolicy.c: fix wrong sp_node insertion

2013-03-08T23:05:34Z

n->end is accessed in sp_insert(). Thus it should be update before calling sp_insert(). This mistake may make kernel panic. Signed-off-by: Hillf Danton Signed-off-by: KOSAKI Motohiro Cc: Sasha Levin Cc: Hugh Dickins Cc: Mel Gorman Cc: Dave Jones Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: use NUMA_NO_NODE

2013-02-24T01:50:21Z

Make a sweep through mm/ and convert code that uses -1 directly to using the more appropriate NUMA_NO_NODE. Signed-off-by: David Rientjes Reviewed-by: Yasuaki Ishimatsu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: remove offlining arg to migrate_pages

2013-02-24T01:50:19Z

No functional change, but the only purpose of the offlining argument to migrate_pages() etc, was to ensure that __unmap_and_move() could migrate a KSM page for memory hotremove (which took ksm_thread_mutex) but not for other callers. Now all cases are safe, remove the arg. Signed-off-by: Hugh Dickins Cc: Rik van Riel Cc: Petr Holasek Cc: Andrea Arcangeli Cc: Izik Eidus Cc: Gerald Schaefer Cc: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ksm: enable KSM page migration

2013-02-24T01:50:19Z

Migration of KSM pages is now safe: remove the PageKsm restrictions from mempolicy.c and migrate.c. But keep PageKsm out of __unmap_and_move()'s anon_vma contortions, which are irrelevant to KSM: it looks as if that code was preventing hotremove migration of KSM pages, unless they happened to be in swapcache. There is some question as to whether enforcing a NUMA mempolicy migration ought to migrate KSM pages, mapped into entirely unrelated processes; but moving page_mapcount > 1 is only permitted with MPOL_MF_MOVE_ALL anyway, and it seems reasonable to assume that you wouldn't set MADV_MERGEABLE on any area where this is a worry. Signed-off-by: Hugh Dickins Cc: Rik van Riel Cc: Petr Holasek Cc: Andrea Arcangeli Cc: Izik Eidus Cc: Gerald Schaefer Cc: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: rename page struct field helpers

2013-02-24T01:50:18Z

The function names page_xchg_last_nid(), page_last_nid() and reset_page_last_nid() were judged to be inconsistent so rename them to a struct_field_op style pattern. As it looked jarring to have reset_page_mapcount() and page_nid_reset_last() beside each other in memmap_init_zone(), this patch also renames reset_page_mapcount() to page_mapcount_reset(). There are others like init_page_count() but as it is used throughout the arch code a rename would likely cause more conflicts than it is worth. [akpm@linux-foundation.org: fix zcache] Signed-off-by: Mel Gorman Suggested-by: Andrew Morton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mempolicy: fix is_valid_nodemask()

2013-02-24T01:50:13Z

is_valid_nodemask() was introduced by commit 19770b32609b ("mm: filter based on a nodemask as well as a gfp_mask"). but it does not match its comments, because it does not check the zone which > policy_zone. Also in commit b377fd3982ad ("Apply memory policies to top two highest zones when highest zone is ZONE_MOVABLE"), this commits told us, if highest zone is ZONE_MOVABLE, we should also apply memory policies to it. so ZONE_MOVABLE should be valid zone for policies. is_valid_nodemask() need to be changed to match it. Fix: check all zones, even its zoneid > policy_zone. Use nodes_intersects() instead open code to check it. Reported-by: Wen Congyang Signed-off-by: Lai Jiangshan Signed-off-by: Tang Chen Cc: Mel Gorman Cc: Lee Schermerhorn Cc: Jiang Liu Cc: Jianguo Wu Cc: Kamezawa Hiroyuki Cc: Lai Jiangshan Cc: Yasuaki Ishimatsu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: mempolicy: Convert shared_policy mutex to spinlock

2013-01-03T01:32:13Z

Sasha was fuzzing with trinity and reported the following problem: BUG: sleeping function called from invalid context at kernel/mutex.c:269 in_atomic(): 1, irqs_disabled(): 0, pid: 6361, name: trinity-main 2 locks held by trinity-main/6361: #0: (&mm->mmap_sem){++++++}, at: [] __do_page_fault+0x1e4/0x4f0 #1: (&(&mm->page_table_lock)->rlock){+.+...}, at: [] handle_pte_fault+0x3f7/0x6a0 Pid: 6361, comm: trinity-main Tainted: G W 3.7.0-rc2-next-20121024-sasha-00001-gd95ef01-dirty #74 Call Trace: __might_sleep+0x1c3/0x1e0 mutex_lock_nested+0x29/0x50 mpol_shared_policy_lookup+0x2e/0x90 shmem_get_policy+0x2e/0x30 get_vma_policy+0x5a/0xa0 mpol_misplaced+0x41/0x1d0 handle_pte_fault+0x465/0x6a0 This was triggered by a different version of automatic NUMA balancing but in theory the current version is vunerable to the same problem. do_numa_page -> numa_migrate_prep -> mpol_misplaced -> get_vma_policy -> shmem_get_policy It's very unlikely this will happen as shared pages are not marked pte_numa -- see the page_mapcount() check in change_pte_range() -- but it is possible. To address this, this patch restores sp->lock as originally implemented by Kosaki Motohiro. In the path where get_vma_policy() is called, it should not be calling sp_alloc() so it is not necessary to treat the PTL specially. Signed-off-by: KOSAKI Motohiro Tested-by: KOSAKI Motohiro Signed-off-by: Mel Gorman Signed-off-by: Linus Torvalds

mempolicy: remove arg from mpol_parse_str, mpol_to_str

2013-01-02T17:27:10Z

Remove the unused argument (formerly no_context) from mpol_parse_str() and from mpol_to_str(). Signed-off-by: Hugh Dickins Signed-off-by: Linus Torvalds