The patch titled
Subject: mm: memcontrol: move memcg_online_kmem() to mem_cgroup_css_online()
has been added to the -mm tree. Its filename is
mm-memcontrol-move-memcg_online_kmem-to-mem_cgroup_css_online.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-memcontrol-move-memcg_online_kmem-to-mem_cgroup_css_online.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-memcontrol-move-memcg_online_kmem-to-mem_cgroup_css_online.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Subject: mm: memcontrol: move memcg_online_kmem() to mem_cgroup_css_online()
It will simplify the code if moving memcg_online_kmem() to
mem_cgroup_css_online() and do not need to set ->kmemcg_id to -1 to
indicate the memcg is offline. In the next patch, ->kmemcg_id will be
used to sync list lru reparenting which requires not to change
->kmemcg_id.
Link: https://lkml.kernel.org/r/20220228122126.37293-10-songmuchun@xxxxxxxxxxxxx
Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Acked-by: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Cc: Alex Shi <alexs@xxxxxxxxxx>
Cc: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
Cc: Chao Yu <chao@xxxxxxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Cc: Fam Zheng <fam.zheng@xxxxxxxxxxxxx>
Cc: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Kari Argillander <kari.argillander@xxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Cc: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Theodore Ts'o <tytso@xxxxxxx>
Cc: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Wei Yang <richard.weiyang@xxxxxxxxx>
Cc: Xiongchun Duan <duanxiongchun@xxxxxxxxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 37 ++++++++++++++++---------------------
1 file changed, 16 insertions(+), 21 deletions(-)
--- a/mm/memcontrol.c~mm-memcontrol-move-memcg_online_kmem-to-mem_cgroup_css_online
+++ a/mm/memcontrol.c
@@ -3667,7 +3667,8 @@ static int memcg_online_kmem(struct mem_
if (cgroup_memory_nokmem)
return 0;
- BUG_ON(memcg->kmemcg_id >= 0);
+ if (unlikely(mem_cgroup_is_root(memcg)))
+ return 0;
memcg_id = memcg_alloc_cache_id();
if (memcg_id < 0)
@@ -3693,7 +3694,10 @@ static void memcg_offline_kmem(struct me
struct mem_cgroup *parent;
int kmemcg_id;
- if (memcg->kmemcg_id == -1)
+ if (cgroup_memory_nokmem)
+ return;
+
+ if (unlikely(mem_cgroup_is_root(memcg)))
return;
parent = parent_mem_cgroup(memcg);
@@ -3703,7 +3707,6 @@ static void memcg_offline_kmem(struct me
memcg_reparent_objcgs(memcg, parent);
kmemcg_id = memcg->kmemcg_id;
- BUG_ON(kmemcg_id < 0);
/*
* After we have finished memcg_reparent_objcgs(), all list_lrus
@@ -3714,7 +3717,6 @@ static void memcg_offline_kmem(struct me
memcg_drain_all_list_lrus(kmemcg_id, parent);
memcg_free_cache_id(kmemcg_id);
- memcg->kmemcg_id = -1;
}
#else
static int memcg_online_kmem(struct mem_cgroup *memcg)
@@ -5234,7 +5236,6 @@ mem_cgroup_css_alloc(struct cgroup_subsy
{
struct mem_cgroup *parent = mem_cgroup_from_css(parent_css);
struct mem_cgroup *memcg, *old_memcg;
- long error = -ENOMEM;
old_memcg = set_active_memcg(parent);
memcg = mem_cgroup_alloc();
@@ -5263,34 +5264,26 @@ mem_cgroup_css_alloc(struct cgroup_subsy
return &memcg->css;
}
- /* The following stuff does not apply to the root */
- error = memcg_online_kmem(memcg);
- if (error)
- goto fail;
-
if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)
static_branch_inc(&memcg_sockets_enabled_key);
return &memcg->css;
-fail:
- mem_cgroup_id_remove(memcg);
- mem_cgroup_free(memcg);
- return ERR_PTR(error);
}
static int mem_cgroup_css_online(struct cgroup_subsys_state *css)
{
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+ if (memcg_online_kmem(memcg))
+ goto remove_id;
+
/*
* A memcg must be visible for expand_shrinker_info()
* by the time the maps are allocated. So, we allocate maps
* here, when for_each_mem_cgroup() can't skip it.
*/
- if (alloc_shrinker_info(memcg)) {
- mem_cgroup_id_remove(memcg);
- return -ENOMEM;
- }
+ if (alloc_shrinker_info(memcg))
+ goto offline_kmem;
/* Online state pins memcg ID, memcg ID pins CSS */
refcount_set(&memcg->id.ref, 1);
@@ -5300,6 +5293,11 @@ static int mem_cgroup_css_online(struct
queue_delayed_work(system_unbound_wq, &stats_flush_dwork,
2UL*HZ);
return 0;
+offline_kmem:
+ memcg_offline_kmem(memcg);
+remove_id:
+ mem_cgroup_id_remove(memcg);
+ return -ENOMEM;
}
static void mem_cgroup_css_offline(struct cgroup_subsys_state *css)
@@ -5357,9 +5355,6 @@ static void mem_cgroup_css_free(struct c
cancel_work_sync(&memcg->high_work);
mem_cgroup_remove_from_trees(memcg);
free_shrinker_info(memcg);
-
- /* Need to offline kmem if online_css() fails */
- memcg_offline_kmem(memcg);
mem_cgroup_free(memcg);
}
_
Patches currently in -mm which might be from songmuchun@xxxxxxxxxxxxx are
mm-list_lru-transpose-the-array-of-per-node-per-memcg-lru-lists.patch
mm-introduce-kmem_cache_alloc_lru.patch
fs-introduce-alloc_inode_sb-to-allocate-filesystems-specific-inode.patch
fs-allocate-inode-by-using-alloc_inode_sb.patch
f2fs-allocate-inode-by-using-alloc_inode_sb.patch
nfs42-use-a-specific-kmem_cache-to-allocate-nfs4_xattr_entry.patch
mm-dcache-use-kmem_cache_alloc_lru-to-allocate-dentry.patch
xarray-use-kmem_cache_alloc_lru-to-allocate-xa_node.patch
mm-memcontrol-move-memcg_online_kmem-to-mem_cgroup_css_online.patch
mm-list_lru-allocate-list_lru_one-only-when-needed.patch
mm-list_lru-rename-memcg_drain_all_list_lrus-to-memcg_reparent_list_lrus.patch
mm-list_lru-replace-linear-array-with-xarray.patch
mm-memcontrol-reuse-memory-cgroup-id-for-kmem-id.patch
mm-memcontrol-fix-cannot-alloc-the-maximum-memcg-id.patch
mm-list_lru-rename-list_lru_per_memcg-to-list_lru_memcg.patch
mm-memcontrol-rename-memcg_cache_id-to-memcg_kmem_id.patch
mm-thp-fix-wrong-cache-flush-in-remove_migration_pmd.patch
mm-fix-missing-cache-flush-for-all-tail-pages-of-compound-page.patch
mm-hugetlb-fix-missing-cache-flush-in-copy_huge_page_from_user.patch
mm-hugetlb-fix-missing-cache-flush-in-hugetlb_mcopy_atomic_pte.patch
mm-shmem-fix-missing-cache-flush-in-shmem_mfill_atomic_pte.patch
mm-userfaultfd-fix-missing-cache-flush-in-mcopy_atomic_pte-and-__mcopy_atomic.patch
mm-replace-multiple-dcache-flush-with-flush_dcache_folio.patch
mm-hugetlb-free-the-2nd-vmemmap-page-associated-with-each-hugetlb-page.patch
mm-hugetlb-replace-hugetlb_free_vmemmap_enabled-with-a-static_key.patch
mm-sparsemem-use-page-table-lock-to-protect-kernel-pmd-operations.patch
selftests-vm-add-a-hugetlb-test-case.patch
mm-sparsemem-move-vmemmap-related-to-hugetlb-to-config_hugetlb_page_free_vmemmap.patch
