The patch titled
memcg: memory hotplug fix for notifier callback
has been removed from the -mm tree. Its filename was
memcg-memory-hotplug-fix-for-notifier-callback.patch
This patch was dropped because it was merged into mainline or a subsystem tree
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: memcg: memory hotplug fix for notifier callback
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Fixes for memcg/memory hotplug.
While memory hotplug allocate/free memmap, page_cgroup doesn't free
page_cgroup at OFFLINE when page_cgroup is allocated via bootomem.
(Because freeing bootmem requires special care.)
Then, if page_cgroup is allocated by bootmem and memmap is freed/allocated
by memory hotplug, page_cgroup->page == page is no longer true.
But current MEM_ONLINE handler doesn't check it and update
page_cgroup->page if it's not necessary to allocate page_cgroup. (This
was not found because memmap is not freed if SPARSEMEM_VMEMMAP is y.)
And I noticed that MEM_ONLINE can be called against "part of section".
So, freeing page_cgroup at CANCEL_ONLINE will cause trouble. (freeing
used page_cgroup) Don't rollback at CANCEL.
One more, current memory hotplug notifier is stopped by slub because it
sets NOTIFY_STOP_MASK to return vaule. So, page_cgroup's callback never
be called. (low priority than slub now.)
I think this slub's behavior is not intentional(BUG). and fixes it.
Another way to be considered about page_cgroup allocation:
- free page_cgroup at OFFLINE even if it's from bootmem
and remove specieal handler. But it requires more changes.
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=12041
Signed-off-by: KAMEZAWA Hiruyoki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Li Zefan <lizf@xxxxxxxxxxxxxx>
Cc: Balbir Singh <balbir@xxxxxxxxxx>
Cc: Pavel Emelyanov <xemul@xxxxxxxxxx>
Tested-by: Badari Pulavarty <pbadari@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_cgroup.c | 43 +++++++++++++++++++++++++++++--------------
mm/slub.c | 6 ++++--
2 files changed, 33 insertions(+), 16 deletions(-)
diff -puN mm/page_cgroup.c~memcg-memory-hotplug-fix-for-notifier-callback mm/page_cgroup.c
--- a/mm/page_cgroup.c~memcg-memory-hotplug-fix-for-notifier-callback
+++ a/mm/page_cgroup.c
@@ -107,19 +107,29 @@ int __init_refok init_section_page_cgrou
section = __pfn_to_section(pfn);
- if (section->page_cgroup)
- return 0;
-
- nid = page_to_nid(pfn_to_page(pfn));
-
- table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
- if (slab_is_available()) {
- base = kmalloc_node(table_size, GFP_KERNEL, nid);
- if (!base)
- base = vmalloc_node(table_size, nid);
- } else {
- base = __alloc_bootmem_node_nopanic(NODE_DATA(nid), table_size,
+ if (!section->page_cgroup) {
+ nid = page_to_nid(pfn_to_page(pfn));
+ table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
+ if (slab_is_available()) {
+ base = kmalloc_node(table_size, GFP_KERNEL, nid);
+ if (!base)
+ base = vmalloc_node(table_size, nid);
+ } else {
+ base = __alloc_bootmem_node_nopanic(NODE_DATA(nid),
+ table_size,
PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
+ }
+ } else {
+ /*
+ * We don't have to allocate page_cgroup again, but
+ * address of memmap may be changed. So, we have to initialize
+ * again.
+ */
+ base = section->page_cgroup + pfn;
+ table_size = 0;
+ /* check address of memmap is changed or not. */
+ if (base->page == pfn_to_page(pfn))
+ return 0;
}
if (!base) {
@@ -208,18 +218,23 @@ static int __meminit page_cgroup_callbac
ret = online_page_cgroup(mn->start_pfn,
mn->nr_pages, mn->status_change_nid);
break;
- case MEM_CANCEL_ONLINE:
case MEM_OFFLINE:
offline_page_cgroup(mn->start_pfn,
mn->nr_pages, mn->status_change_nid);
break;
+ case MEM_CANCEL_ONLINE:
case MEM_GOING_OFFLINE:
break;
case MEM_ONLINE:
case MEM_CANCEL_OFFLINE:
break;
}
- ret = notifier_from_errno(ret);
+
+ if (ret)
+ ret = notifier_from_errno(ret);
+ else
+ ret = NOTIFY_OK;
+
return ret;
}
diff -puN mm/slub.c~memcg-memory-hotplug-fix-for-notifier-callback mm/slub.c
--- a/mm/slub.c~memcg-memory-hotplug-fix-for-notifier-callback
+++ a/mm/slub.c
@@ -2931,8 +2931,10 @@ static int slab_memory_callback(struct n
case MEM_CANCEL_OFFLINE:
break;
}
-
- ret = notifier_from_errno(ret);
+ if (ret)
+ ret = notifier_from_errno(ret);
+ else
+ ret = NOTIFY_OK;
return ret;
}
_
Patches currently in -mm which might be from kamezawa.hiroyu@xxxxxxxxxxxxxx are
vmscan-evict-streaming-io-first.patch
mm-gup-persist-for-write-permission.patch
mm-wp-lock-page-before-deciding-cow.patch
mm-reuse_swap_page-replaces-can_share_swap_page.patch
mm-try_to_free_swap-replaces-remove_exclusive_swap_page.patch
mm-try_to_unuse-check-removing-right-swap.patch
mm-remove-try_to_munlock-from-vmscan.patch
mm-remove-gfp_mask-from-add_to_swap.patch
mm-add-add_to_swap-stub.patch
mm-optimize-get_scan_ratio-for-no-swap.patch
memcg-reclaim-shouldnt-change-zone-recent_rotated-statistics.patch
swapfile-swapon-needs-larger-size-type.patch
swapfile-remove-swp_active-mask.patch
swapfile-remove-surplus-whitespace.patch
swapfile-remove-v0-swap-space-message.patch
swapfile-rearrange-scan-and-swap_info.patch
swapfile-swapon-use-discard-trim.patch
swapfile-swap-allocation-use-discard.patch
swapfile-swapon-randomize-if-nonrot.patch
swapfile-swap-allocation-cycle-if-nonrot.patch
cgroups-make-cgroup-config-a-submenu.patch
cgroups-documentation-updates.patch
cgroups-remove-some-redundant-null-checks.patch
ns_cgroup-remove-unused-spinlock.patch
memcg-fix-a-typo-in-kconfig.patch
cgroups-add-lock-for-child-cgroups-in-cgroup_post_fork.patch
cgroups-fix-cgroup_iter_next-bug.patch
cgroups-dont-put-struct-cgroupfs_root-protected-by-rcu.patch
cgroups-use-task_lock-for-access-tsk-cgroups-safe-in-cgroup_clone.patch
cgroups-call-find_css_set-safely-in-cgroup_attach_task.patch
cgroups-remove-rcu_read_lock-in-cgroupstats_build.patch
cgroups-make-root_list-contains-active-hierarchies-only.patch
cgroups-add-inactive-subsystems-to-rootnodesubsys_list.patch
cgroups-introduce-link_css_set-to-remove-duplicate-code.patch
devcgroup-use-list_for_each_entry_rcu.patch
memcg-introduce-charge-commit-cancel-style-of-functions.patch
memcg-introduce-charge-commit-cancel-style-of-functions-fix.patch
memcg-fix-gfp_mask-of-callers-of-charge.patch
memcg-simple-migration-handling.patch
memcg-do-not-recalculate-section-unnecessarily-in-init_section_page_cgroup.patch
memcg-move-all-acccounts-to-parent-at-rmdir.patch
memcg-reduce-size-of-mem_cgroup-by-using-nr_cpu_ids.patch
memcg-new-force_empty-to-free-pages-under-group.patch
memcg-new-force_empty-to-free-pages-under-group-fix.patch
memcg-new-force_empty-to-free-pages-under-group-fix-fix.patch
memcg-handle-swap-caches.patch
memcg-handle-swap-caches-build-fix.patch
memcg-memswap-controller-kconfig.patch
memcg-swap-cgroup-for-remembering-usage.patch
memcg-memswap-controller-core.patch
memcg-memswap-controller-core-make-resize-limit-hold-mutex.patch
memcg-memswap-controller-core-swapcache-fixes.patch
memcg-synchronized-lru.patch
memcg-add-mem_cgroup_disabled.patch
memcg-add-mem_cgroup_disabled-fix.patch
memory-cgroup-hierarchy-documentation-v4.patch
memory-cgroup-resource-counters-for-hierarchy-v4.patch
memory-cgroup-resource-counters-for-hierarchy-v4-checkpatch-fixes.patch
memory-cgroup-hierarchical-reclaim-v4.patch
memory-cgroup-hierarchical-reclaim-v4-checkpatch-fixes.patch
memory-cgroup-hierarchical-reclaim-v4-fix-for-hierarchical-reclaim.patch
memory-cgroup-hierarchy-feature-selector-v4.patch
memory-cgroup-hierarchy-feature-selector-v4-fix.patch
memcontrol-rcu_read_lock-to-protect-mm_match_cgroup.patch
memcg-avoid-unnecessary-system-wide-oom-killer.patch
memcg-avoid-unnecessary-system-wide-oom-killer-fix.patch
memcg-fix-reclaim-result-checks.patch
cpuset-rcu_read_lock-to-protect-task_cs.patch
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