| Message ID | 4456276af198412b2d41cd09d246cd20e0c6d22a.1582581887.git.schatzberg.dan@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Charge loop device i/o to issuing cgroup | expand |
On Mon, 24 Feb 2020, Dan Schatzberg wrote: > 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). > > Signed-off-by: Dan Schatzberg <schatzberg.dan@gmail.com> > Acked-by: Johannes Weiner <hannes@cmpxchg.org> > Acked-by: Tejun Heo <tj@kernel.org> > Acked-by: Chris Down <chris@chrisdown.name> Acked-by: Hugh Dickins <hughd@google.com> > Reviewed-by: Shakeel Butt <shakeelb@google.com> > Signed-off-by: Dan Schatzberg <schatzberg.dan@gmail.com> > --- > mm/memcontrol.c | 11 ++++++++--- > mm/shmem.c | 4 ++-- > 2 files changed, 10 insertions(+), 5 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index d09776cd6e10..222e4aac0c85 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -6319,7 +6319,8 @@ enum mem_cgroup_protection mem_cgroup_protected(struct mem_cgroup *root, > * @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. > @@ -6363,8 +6364,12 @@ int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm, > } > } > > - 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); > > diff --git a/mm/shmem.c b/mm/shmem.c > index c8f7540ef048..8664c97851f2 100644 > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -1631,7 +1631,7 @@ static int shmem_swapin_page(struct inode *inode, pgoff_t index, > { > 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 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, > } > > 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)) { > -- > 2.17.1
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index d09776cd6e10..222e4aac0c85 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -6319,7 +6319,8 @@ enum mem_cgroup_protection mem_cgroup_protected(struct mem_cgroup *root, * @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. @@ -6363,8 +6364,12 @@ int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm, } } - 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); diff --git a/mm/shmem.c b/mm/shmem.c index c8f7540ef048..8664c97851f2 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1631,7 +1631,7 @@ static int shmem_swapin_page(struct inode *inode, pgoff_t index, { 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 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, } 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)) {