The patch titled
Subject: mm: charge active memcg when no mm is set
has been added to the -mm tree. Its filename is
mm-charge-active-memcg-when-no-mm-is-set.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-charge-active-memcg-when-no-mm-is-set.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-charge-active-memcg-when-no-mm-is-set.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: Dan Schatzberg <schatzberg.dan@xxxxxxxxx>
Subject: mm: charge active memcg when no mm is set
memalloc_use_memcg() worked for kernel allocations but was silently
ignored for user pages.
This patch establishes a precedence order for who gets charged:
1. If there is a memcg associated with the page already, that memcg is
charged. This happens during swapin.
2. If an explicit mm is passed, mm->memcg is charged. This happens
during page faults, which can be triggered in remote VMs (eg gup).
3. Otherwise consult the current process context. If it has configured
a current->active_memcg, use that. Otherwise, current->mm->memcg.
Previously, if a NULL mm was passed to mem_cgroup_try_charge (case 3) it
would always charge the root cgroup. Now it looks up the current
active_memcg first (falling back to charging the root cgroup if not set).
Link: http://lkml.kernel.org/r/4456276af198412b2d41cd09d246cd20e0c6d22a.1582581887.git.schatzberg.dan@xxxxxxxxx
Signed-off-by: Dan Schatzberg <schatzberg.dan@xxxxxxxxx>
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Acked-by: Tejun Heo <tj@xxxxxxxxxx>
Acked-by: Chris Down <chris@xxxxxxxxxxxxxx>
Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
Acked-by: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Li Zefan <lizefan@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Roman Gushchin <guro@xxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
Cc: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 11 ++++++++---
mm/shmem.c | 4 ++--
2 files changed, 10 insertions(+), 5 deletions(-)
--- a/mm/memcontrol.c~mm-charge-active-memcg-when-no-mm-is-set
+++ a/mm/memcontrol.c
@@ -6320,7 +6320,8 @@ exit:
* @compound: charge the page as compound or small page
*
* Try to charge @page to the memcg that @mm belongs to, reclaiming
- * pages according to @gfp_mask if necessary.
+ * pages according to @gfp_mask if necessary. If @mm is NULL, try to
+ * charge to the active memcg.
*
* Returns 0 on success, with *@memcgp pointing to the charged memcg.
* Otherwise, an error code is returned.
@@ -6364,8 +6365,12 @@ int mem_cgroup_try_charge(struct page *p
}
}
- if (!memcg)
- memcg = get_mem_cgroup_from_mm(mm);
+ if (!memcg) {
+ if (!mm)
+ memcg = get_mem_cgroup_from_current();
+ else
+ memcg = get_mem_cgroup_from_mm(mm);
+ }
ret = try_charge(memcg, gfp_mask, nr_pages);
--- a/mm/shmem.c~mm-charge-active-memcg-when-no-mm-is-set
+++ a/mm/shmem.c
@@ -1631,7 +1631,7 @@ static int shmem_swapin_page(struct inod
{
struct address_space *mapping = inode->i_mapping;
struct shmem_inode_info *info = SHMEM_I(inode);
- struct mm_struct *charge_mm = vma ? vma->vm_mm : current->mm;
+ struct mm_struct *charge_mm = vma ? vma->vm_mm : NULL;
struct mem_cgroup *memcg;
struct page *page;
swp_entry_t swap;
@@ -1766,7 +1766,7 @@ repeat:
}
sbinfo = SHMEM_SB(inode->i_sb);
- charge_mm = vma ? vma->vm_mm : current->mm;
+ charge_mm = vma ? vma->vm_mm : NULL;
page = find_lock_entry(mapping, index);
if (xa_is_value(page)) {
_
Patches currently in -mm which might be from schatzberg.dan@xxxxxxxxx are
loop-use-worker-per-cgroup-instead-of-kworker.patch
mm-charge-active-memcg-when-no-mm-is-set.patch
loop-charge-i-o-to-mem-and-blk-cg.patch
