The patch titled
ksm: three remove_rmap_item_from_tree cleanups
has been added to the -mm tree. Its filename is
ksm-three-remove_rmap_item_from_tree-cleanups.patch
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out what to do about this
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------------------------------------------------------
Subject: ksm: three remove_rmap_item_from_tree cleanups
From: Hugh Dickins <hugh.dickins@xxxxxxxxxxxxx>
1. remove_rmap_item_from_tree() is called as a precaution from
various places: don't dirty the rmap_item cacheline unnecessarily,
just mask the flags out of the address when they have been set.
2. First get_next_rmap_item() removes an unstable rmap_item from its tree,
then shortly afterwards cmp_and_merge_page() removes a stable rmap_item
from its tree: it's easier just to do both at once (but definitely keep
the BUG_ON(age > 1) which guards against a future omission).
3. When cmp_and_merge_page() moves an rmap_item from unstable to stable
tree, it does its own rb_erase() and accounting: that's better
expressed by remove_rmap_item_from_tree().
Signed-off-by: Hugh Dickins <hugh.dickins@xxxxxxxxxxxxx>
Cc: Izik Eidus <ieidus@xxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/ksm.c | 17 ++++++-----------
1 file changed, 6 insertions(+), 11 deletions(-)
diff -puN mm/ksm.c~ksm-three-remove_rmap_item_from_tree-cleanups mm/ksm.c
--- a/mm/ksm.c~ksm-three-remove_rmap_item_from_tree-cleanups
+++ a/mm/ksm.c
@@ -453,6 +453,7 @@ static void remove_rmap_item_from_tree(s
}
rmap_item->next = NULL;
+ rmap_item->address &= PAGE_MASK;
} else if (rmap_item->address & NODE_FLAG) {
unsigned char age;
@@ -467,11 +468,11 @@ static void remove_rmap_item_from_tree(s
BUG_ON(age > 1);
if (!age)
rb_erase(&rmap_item->node, &root_unstable_tree);
+
ksm_pages_unshared--;
+ rmap_item->address &= PAGE_MASK;
}
- rmap_item->address &= PAGE_MASK;
-
cond_resched(); /* we're called from many long loops */
}
@@ -1086,8 +1087,7 @@ static void cmp_and_merge_page(struct pa
unsigned int checksum;
int err;
- if (in_stable_tree(rmap_item))
- remove_rmap_item_from_tree(rmap_item);
+ remove_rmap_item_from_tree(rmap_item);
/* We first start with searching the page inside the stable tree */
tree_rmap_item = stable_tree_search(page, page2, rmap_item);
@@ -1143,9 +1143,7 @@ static void cmp_and_merge_page(struct pa
* tree, and insert it instead as new node in the stable tree.
*/
if (!err) {
- rb_erase(&tree_rmap_item->node, &root_unstable_tree);
- tree_rmap_item->address &= ~NODE_FLAG;
- ksm_pages_unshared--;
+ remove_rmap_item_from_tree(tree_rmap_item);
/*
* If we fail to insert the page into the stable tree,
@@ -1174,11 +1172,8 @@ static struct rmap_item *get_next_rmap_i
while (cur != &mm_slot->rmap_list) {
rmap_item = list_entry(cur, struct rmap_item, link);
- if ((rmap_item->address & PAGE_MASK) == addr) {
- if (!in_stable_tree(rmap_item))
- remove_rmap_item_from_tree(rmap_item);
+ if ((rmap_item->address & PAGE_MASK) == addr)
return rmap_item;
- }
if (rmap_item->address > addr)
break;
cur = cur->next;
_
Patches currently in -mm which might be from hugh.dickins@xxxxxxxxxxxxx are
mmap-dont-return-enomem-when-mapcount-is-temporarily-exceeded-in-munmap.patch
mmap-dont-return-enomem-when-mapcount-is-temporarily-exceeded-in-munmap-checkpatch-fixes.patch
vmalloc-adjust-gfp-mask-passed-on-nested-vmalloc-invocation.patch
swap_info-private-to-swapfilec.patch
swap_info-change-to-array-of-pointers.patch
swap_info-include-first_swap_extent.patch
swap_info-include-first_swap_extent-fix.patch
swap_info-include-first_swap_extent-fix-fix.patch
swap_info-miscellaneous-minor-cleanups.patch
swap_info-swap_has_cache-cleanups.patch
swap_info-swap_map-of-chars-not-shorts.patch
swap_info-swap-count-continuations.patch
swap_info-note-swap_map_shmem.patch
swap_info-reorder-its-fields.patch
rmap-fix-the-comment-for-try_to_unmap_anon.patch
oom_kill-use-rss-value-instead-of-vm-size-for-badness.patch
mm-define-page_mapping_flags.patch
mm-mlocking-in-try_to_unmap_one.patch
mm-config_mmu-for-pg_mlocked.patch
mm-pass-address-down-to-rmap-ones.patch
mm-stop-ptlock-enlarging-struct-page.patch
mm-sigbus-instead-of-abusing-oom.patch
ksm-three-remove_rmap_item_from_tree-cleanups.patch
ksm-remove-redundancies-when-merging-page.patch
ksm-cleanup-some-function-arguments.patch
ksm-singly-linked-rmap_list.patch
ksm-separate-stable_node.patch
ksm-stable_node-point-to-page-and-back.patch
elf-kill-use_elf_core_dump.patch
prio_tree-debugging-patch.patch
--
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