The patch titled
ksm: move pages_sharing updates
has been added to the -mm tree. Its filename is
ksm-move-pages_sharing-updates.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: ksm: move pages_sharing updates
From: Hugh Dickins <hugh.dickins@xxxxxxxxxxxxx>
The pages_shared count is incremented and decremented when adding a node
to and removing a node from the stable tree: easy to understand. But the
pages_sharing count was hard to follow, being adjusted in various places:
increment and decrement it when adding to and removing from the stable tree.
And the pages_sharing variable used to include the pages_shared, then those
were subtracted when shown in the pages_sharing sysfs file: now keep it as
an exclusive count of leaves hanging off the stable tree nodes, throughout.
Signed-off-by: Hugh Dickins <hugh.dickins@xxxxxxxxxxxxx>
Acked-by: Izik Eidus <ieidus@xxxxxxxxxx>
Acked-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/ksm.c | 24 +++++++++---------------
1 file changed, 9 insertions(+), 15 deletions(-)
diff -puN mm/ksm.c~ksm-move-pages_sharing-updates mm/ksm.c
--- a/mm/ksm.c~ksm-move-pages_sharing-updates
+++ a/mm/ksm.c
@@ -152,7 +152,7 @@ static struct kmem_cache *mm_slot_cache;
/* The number of nodes in the stable tree */
static unsigned long ksm_pages_shared;
-/* The number of page slots sharing those nodes */
+/* The number of page slots additionally sharing those nodes */
static unsigned long ksm_pages_sharing;
/* Limit on the number of unswappable pages used */
@@ -382,6 +382,7 @@ static void remove_rmap_item_from_tree(s
&next_item->node,
&root_stable_tree);
next_item->address |= NODE_FLAG;
+ ksm_pages_sharing--;
} else {
rb_erase(&rmap_item->node, &root_stable_tree);
ksm_pages_shared--;
@@ -395,10 +396,10 @@ static void remove_rmap_item_from_tree(s
BUG_ON(next_item->prev != rmap_item);
next_item->prev = rmap_item->prev;
}
+ ksm_pages_sharing--;
}
rmap_item->next = NULL;
- ksm_pages_sharing--;
} else if (rmap_item->address & NODE_FLAG) {
unsigned char age;
@@ -786,8 +787,6 @@ static int try_to_merge_two_pages(struct
*/
if (err)
break_cow(mm1, addr1);
- else
- ksm_pages_sharing += 2;
}
put_page(kpage);
@@ -816,9 +815,6 @@ static int try_to_merge_with_ksm_page(st
err = try_to_merge_one_page(vma, page1, kpage);
up_read(&mm1->mmap_sem);
- if (!err)
- ksm_pages_sharing++;
-
return err;
}
@@ -935,13 +931,12 @@ static struct rmap_item *stable_tree_ins
}
}
- ksm_pages_shared++;
-
rmap_item->address |= NODE_FLAG | STABLE_FLAG;
rmap_item->next = NULL;
rb_link_node(&rmap_item->node, parent, new);
rb_insert_color(&rmap_item->node, &root_stable_tree);
+ ksm_pages_shared++;
return rmap_item;
}
@@ -1026,6 +1021,8 @@ static void stable_tree_append(struct rm
tree_rmap_item->next = rmap_item;
rmap_item->address |= STABLE_FLAG;
+
+ ksm_pages_sharing++;
}
/*
@@ -1050,10 +1047,9 @@ static void cmp_and_merge_page(struct pa
/* We first start with searching the page inside the stable tree */
tree_rmap_item = stable_tree_search(page, page2, rmap_item);
if (tree_rmap_item) {
- if (page == page2[0]) { /* forked */
- ksm_pages_sharing++;
+ if (page == page2[0]) /* forked */
err = 0;
- } else
+ else
err = try_to_merge_with_ksm_page(rmap_item->mm,
rmap_item->address,
page, page2[0]);
@@ -1114,7 +1110,6 @@ static void cmp_and_merge_page(struct pa
break_cow(tree_rmap_item->mm,
tree_rmap_item->address);
break_cow(rmap_item->mm, rmap_item->address);
- ksm_pages_sharing -= 2;
}
}
@@ -1482,8 +1477,7 @@ KSM_ATTR_RO(pages_shared);
static ssize_t pages_sharing_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%lu\n",
- ksm_pages_sharing - ksm_pages_shared);
+ return sprintf(buf, "%lu\n", ksm_pages_sharing);
}
KSM_ATTR_RO(pages_sharing);
_
Patches currently in -mm which might be from hugh.dickins@xxxxxxxxxxxxx are
acpi-fix-null-bug-for-hid-uid-string.patch
mm-oom-analysis-add-shmem-vmstat.patch
ksm-add-mmu_notifier-set_pte_at_notify.patch
ksm-first-tidy-up-madvise_vma.patch
ksm-define-madv_mergeable-and-madv_unmergeable.patch
ksm-the-mm-interface-to-ksm.patch
ksm-no-debug-in-page_dup_rmap.patch
ksm-identify-pageksm-pages.patch
ksm-kernel-samepage-merging.patch
ksm-prevent-mremap-move-poisoning.patch
ksm-change-copyright-message.patch
ksm-change-ksm-nice-level-to-be-5.patch
ksm-rename-kernel_pages_allocated.patch
ksm-move-pages_sharing-updates.patch
ksm-pages_unshared-and-pages_volatile.patch
ksm-break-cow-once-unshared.patch
ksm-keep-quiet-while-list-empty.patch
ksm-five-little-cleanups.patch
ksm-fix-endless-loop-on-oom.patch
ksm-distribute-remove_mm_from_lists.patch
ksm-fix-oom-deadlock.patch
ksm-sysfs-and-defaults.patch
ksm-add-some-documentation.patch
ksm-remove-vm_mergeable_flags.patch
getrusage-fill-ru_maxrss-value.patch
getrusage-fill-ru_maxrss-value-update.patch
ramfs-move-ramfs_magic-to-include-linux-magich.patch
memory-controller-soft-limit-organize-cgroups-v9-fix.patch
prio_tree-debugging-patch.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
