linux-stable.git/mm, branch v2.6.38

Revert "oom: oom_kill_process: fix the child_points logic"

2011-03-14T22:17:07+00:00

This reverts the parent commit.  I hate doing that, but it's generating
some discussion ("half of it is right"), and since I am planning on
doing the 2.6.38 release later today we can punt it to stable if
required. Let's not rock the boat right now.

Signed-off-by: Linus Torvalds

oom: oom_kill_process: fix the child_points logic

2011-03-14T20:38:35+00:00

oom_kill_process() starts with victim_points == 0.  This means that
(most likely) any child has more points and can be killed erroneously.

Also, "children has a different mm" doesn't match the reality, we should
check child->mm != t->mm.  This check is not exactly correct if t->mm ==
NULL but this doesn't really matter, oom_kill_task() will kill them
anyway.

Note: "Kill all processes sharing p->mm" in oom_kill_task() is wrong
too.

Signed-off-by: Oleg Nesterov 
Signed-off-by: Linus Torvalds

thp+memcg-numa: fix BUG at include/linux/mm.h:370!

2011-03-14T15:29:50+00:00

THP's collapse_huge_page() has an understandable but ugly difference
in when its huge page is allocated: inside if NUMA but outside if not.
It's hardly surprising that the memcg failure path forgot that, freeing
the page in the non-NUMA case, then hitting a VM_BUG_ON in get_page()
(or even worse, using the freed page).

Signed-off-by: Hugh Dickins 
Reviewed-by: Minchan Kim 
Signed-off-by: Linus Torvalds

thp: fix page_referenced to modify mapcount/vm_flags only if page is found

2011-03-13T22:35:57+00:00

When vmscan.c calls page_referenced(), if an anon page was created
before a process forked, rmap will search for it in both of the
processes, even though one of them might have since broken COW.

If the child process mlocks the vma where the COWed page belongs to,
page_referenced() running on the page mapped by the parent would lead to
*vm_flags getting VM_LOCKED set erroneously (leading to the references
on the parent page being ignored and evicting the parent page too
early).

*mapcount would also be decremented by page_referenced_one even if the
page wasn't found by page_check_address.

This also lets pmdp_clear_flush_young_notify() go ahead on a
pmd_trans_splitting() pmd.

We hold the page_table_lock so __split_huge_page_map() must wait the
pmdp_clear_flush_young_notify() to complete before it can modify the
pmd.  The pmd is also still mapped in userland so the young bit may
materialize through a tlb miss before split_huge_page_map runs.

This will provide a more accurate page_referenced() behavior during
split_huge_page().

Signed-off-by: Andrea Arcangeli 
Reported-by: Michel Lespinasse 
Reviewed-by: Michel Lespinasse 
Reviewed-by: Minchan Kim 
Reviewed-by: Johannes Weiner 
Reviewed-by: Rik van Riel
Reviewed-by: KOSAKI Motohiro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: use correct numa policy node for transparent hugepages

2011-03-05T01:53:39+00:00

Pass down the correct node for a transparent hugepage allocation.  Most
callers continue to use the current node, however the hugepaged daemon
now uses the previous node of the first to be collapsed page instead.
This ensures that khugepaged does not mess up local memory for an
existing process which uses local policy.

The choice of node is somewhat primitive currently: it just uses the
node of the first page in the pmd range.  An alternative would be to
look at multiple pages and use the most popular node.  I used the
simplest variant for now which should work well enough for the case of
all pages being on the same node.

[akpm@linux-foundation.org: coding-style fixes]
Acked-by: Andrea Arcangeli 
Signed-off-by: Andi Kleen 
Reviewed-by: KAMEZAWA Hiroyuki 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: preserve original node for transparent huge page copies

2011-03-05T01:53:39+00:00

This makes a difference for LOCAL policy, where the node cannot be
determined from the policy itself, but has to be gotten from the original
page.

Acked-by: Andrea Arcangeli 
Signed-off-by: Andi Kleen 
Reviewed-by: KAMEZAWA Hiroyuki 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: change alloc_pages_vma to pass down the policy node for local policy

2011-03-05T01:53:39+00:00

Currently alloc_pages_vma() always uses the local node as policy node for
the LOCAL policy.  Pass this node down as an argument instead.

No behaviour change from this patch, but will be needed for followons.

Acked-by: Andrea Arcangeli 
Signed-off-by: Andi Kleen 
Reviewed-by: KAMEZAWA Hiroyuki 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memcg: more mem_cgroup_uncharge() batching

2011-02-25T23:07:37+00:00

It seems odd that truncate_inode_pages_range(), called not only when
truncating but also when evicting inodes, has mem_cgroup_uncharge_start
and _end() batching in its second loop to clear up a few leftovers, but
not in its first loop that does almost all the work: add them there too.

Signed-off-by: Hugh Dickins 
Acked-by: KAMEZAWA Hiroyuki 
Acked-by: Balbir Singh 
Acked-by: Daisuke Nishimura 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

thp: fix interleaving for transparent hugepages

2011-02-25T23:07:37+00:00

The THP code didn't pass the correct interleaving shift to the memory
policy code.  Fix this here by adjusting for the order.

Signed-off-by: Andi Kleen 
Reviewed-by: Christoph Lameter 
Acked-by: Andrea Arcangeli 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: fix dubious code in __count_immobile_pages()

2011-02-25T23:07:37+00:00

When pfn_valid_within() failed 'iter' was incremented twice.

Signed-off-by: Namhyung Kim 
Reviewed-by: KAMEZAWA Hiroyuki 
Reviewed-by: Minchan Kim 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds