diff mbox series

[v2,4/6] mm: unify SLAB and SLUB page accounting

Message ID 20190423213133.3551969-5-guro@fb.com (mailing list archive)
State New, archived
Headers show
Series mm: reparent slab memory on cgroup removal | expand

Commit Message

Roman Gushchin April 23, 2019, 9:31 p.m. UTC
Currently the page accounting code is duplicated in SLAB and SLUB
internals. Let's move it into new (un)charge_slab_page helpers
in the slab_common.c file. These helpers will be responsible
for statistics (global and memcg-aware) and memcg charging.
So they are replacing direct memcg_(un)charge_slab() calls.

Signed-off-by: Roman Gushchin <guro@fb.com>
---
 mm/slab.c | 19 +++----------------
 mm/slab.h | 22 ++++++++++++++++++++++
 mm/slub.c | 14 ++------------
 3 files changed, 27 insertions(+), 28 deletions(-)

Comments

Shakeel Butt April 24, 2019, 5:23 p.m. UTC | #1
Hi Roman,

On Tue, Apr 23, 2019 at 9:30 PM Roman Gushchin <guro@fb.com> wrote:
>
> Currently the page accounting code is duplicated in SLAB and SLUB
> internals. Let's move it into new (un)charge_slab_page helpers
> in the slab_common.c file. These helpers will be responsible
> for statistics (global and memcg-aware) and memcg charging.
> So they are replacing direct memcg_(un)charge_slab() calls.
>
> Signed-off-by: Roman Gushchin <guro@fb.com>
> ---
>  mm/slab.c | 19 +++----------------
>  mm/slab.h | 22 ++++++++++++++++++++++
>  mm/slub.c | 14 ++------------
>  3 files changed, 27 insertions(+), 28 deletions(-)
>
> diff --git a/mm/slab.c b/mm/slab.c
> index 14466a73d057..53e6b2687102 100644
> --- a/mm/slab.c
> +++ b/mm/slab.c
> @@ -1389,7 +1389,6 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
>                                                                 int nodeid)
>  {
>         struct page *page;
> -       int nr_pages;
>
>         flags |= cachep->allocflags;
>
> @@ -1399,17 +1398,11 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
>                 return NULL;
>         }
>
> -       if (memcg_charge_slab(page, flags, cachep->gfporder, cachep)) {
> +       if (charge_slab_page(page, flags, cachep->gfporder, cachep)) {
>                 __free_pages(page, cachep->gfporder);
>                 return NULL;
>         }
>
> -       nr_pages = (1 << cachep->gfporder);
> -       if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
> -               mod_lruvec_page_state(page, NR_SLAB_RECLAIMABLE, nr_pages);
> -       else
> -               mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE, nr_pages);
> -
>         __SetPageSlab(page);
>         /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */
>         if (sk_memalloc_socks() && page_is_pfmemalloc(page))
> @@ -1424,12 +1417,6 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
>  static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
>  {
>         int order = cachep->gfporder;
> -       unsigned long nr_freed = (1 << order);
> -
> -       if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
> -               mod_lruvec_page_state(page, NR_SLAB_RECLAIMABLE, -nr_freed);
> -       else
> -               mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE, -nr_freed);
>
>         BUG_ON(!PageSlab(page));
>         __ClearPageSlabPfmemalloc(page);
> @@ -1438,8 +1425,8 @@ static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
>         page->mapping = NULL;
>
>         if (current->reclaim_state)
> -               current->reclaim_state->reclaimed_slab += nr_freed;
> -       memcg_uncharge_slab(page, order, cachep);
> +               current->reclaim_state->reclaimed_slab += 1 << order;
> +       uncharge_slab_page(page, order, cachep);
>         __free_pages(page, order);
>  }
>
> diff --git a/mm/slab.h b/mm/slab.h
> index 4a261c97c138..0f5c5444acf1 100644
> --- a/mm/slab.h
> +++ b/mm/slab.h
> @@ -205,6 +205,12 @@ ssize_t slabinfo_write(struct file *file, const char __user *buffer,
>  void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
>  int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
>
> +static inline int cache_vmstat_idx(struct kmem_cache *s)
> +{
> +       return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
> +               NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE;
> +}
> +
>  #ifdef CONFIG_MEMCG_KMEM
>
>  /* List of all root caches. */
> @@ -352,6 +358,22 @@ static inline void memcg_link_cache(struct kmem_cache *s,
>
>  #endif /* CONFIG_MEMCG_KMEM */
>
> +static __always_inline int charge_slab_page(struct page *page,
> +                                           gfp_t gfp, int order,
> +                                           struct kmem_cache *s)
> +{
> +       memcg_charge_slab(page, gfp, order, s);

This does not seem right. Why the return of memcg_charge_slab is ignored?


> +       mod_lruvec_page_state(page, cache_vmstat_idx(s), 1 << order);
> +       return 0;
> +}
> +
> +static __always_inline void uncharge_slab_page(struct page *page, int order,
> +                                              struct kmem_cache *s)
> +{
> +       mod_lruvec_page_state(page, cache_vmstat_idx(s), -(1 << order));
> +       memcg_uncharge_slab(page, order, s);
> +}
> +
>  static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
>  {
>         struct kmem_cache *cachep;
> diff --git a/mm/slub.c b/mm/slub.c
> index 195f61785c7d..90563c0b3b5f 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -1499,7 +1499,7 @@ static inline struct page *alloc_slab_page(struct kmem_cache *s,
>         else
>                 page = __alloc_pages_node(node, flags, order);
>
> -       if (page && memcg_charge_slab(page, flags, order, s)) {
> +       if (page && charge_slab_page(page, flags, order, s)) {
>                 __free_pages(page, order);
>                 page = NULL;
>         }
> @@ -1692,11 +1692,6 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
>         if (!page)
>                 return NULL;
>
> -       mod_lruvec_page_state(page,
> -               (s->flags & SLAB_RECLAIM_ACCOUNT) ?
> -               NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
> -               1 << oo_order(oo));
> -
>         inc_slabs_node(s, page_to_nid(page), page->objects);
>
>         return page;
> @@ -1730,18 +1725,13 @@ static void __free_slab(struct kmem_cache *s, struct page *page)
>                         check_object(s, page, p, SLUB_RED_INACTIVE);
>         }
>
> -       mod_lruvec_page_state(page,
> -               (s->flags & SLAB_RECLAIM_ACCOUNT) ?
> -               NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
> -               -pages);
> -
>         __ClearPageSlabPfmemalloc(page);
>         __ClearPageSlab(page);
>
>         page->mapping = NULL;
>         if (current->reclaim_state)
>                 current->reclaim_state->reclaimed_slab += pages;
> -       memcg_uncharge_slab(page, order, s);
> +       uncharge_slab_page(page, order, s);
>         __free_pages(page, order);
>  }
>
> --
> 2.20.1
>
Roman Gushchin April 24, 2019, 7:17 p.m. UTC | #2
On Wed, Apr 24, 2019 at 10:23:45AM -0700, Shakeel Butt wrote:
> Hi Roman,
> 
> On Tue, Apr 23, 2019 at 9:30 PM Roman Gushchin <guro@fb.com> wrote:
> >
> > Currently the page accounting code is duplicated in SLAB and SLUB
> > internals. Let's move it into new (un)charge_slab_page helpers
> > in the slab_common.c file. These helpers will be responsible
> > for statistics (global and memcg-aware) and memcg charging.
> > So they are replacing direct memcg_(un)charge_slab() calls.
> >
> > Signed-off-by: Roman Gushchin <guro@fb.com>
> > ---
> >  mm/slab.c | 19 +++----------------
> >  mm/slab.h | 22 ++++++++++++++++++++++
> >  mm/slub.c | 14 ++------------
> >  3 files changed, 27 insertions(+), 28 deletions(-)
> >
> > diff --git a/mm/slab.c b/mm/slab.c
> > index 14466a73d057..53e6b2687102 100644
> > --- a/mm/slab.c
> > +++ b/mm/slab.c
> > @@ -1389,7 +1389,6 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
> >                                                                 int nodeid)
> >  {
> >         struct page *page;
> > -       int nr_pages;
> >
> >         flags |= cachep->allocflags;
> >
> > @@ -1399,17 +1398,11 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
> >                 return NULL;
> >         }
> >
> > -       if (memcg_charge_slab(page, flags, cachep->gfporder, cachep)) {
> > +       if (charge_slab_page(page, flags, cachep->gfporder, cachep)) {
> >                 __free_pages(page, cachep->gfporder);
> >                 return NULL;
> >         }
> >
> > -       nr_pages = (1 << cachep->gfporder);
> > -       if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
> > -               mod_lruvec_page_state(page, NR_SLAB_RECLAIMABLE, nr_pages);
> > -       else
> > -               mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE, nr_pages);
> > -
> >         __SetPageSlab(page);
> >         /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */
> >         if (sk_memalloc_socks() && page_is_pfmemalloc(page))
> > @@ -1424,12 +1417,6 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
> >  static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
> >  {
> >         int order = cachep->gfporder;
> > -       unsigned long nr_freed = (1 << order);
> > -
> > -       if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
> > -               mod_lruvec_page_state(page, NR_SLAB_RECLAIMABLE, -nr_freed);
> > -       else
> > -               mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE, -nr_freed);
> >
> >         BUG_ON(!PageSlab(page));
> >         __ClearPageSlabPfmemalloc(page);
> > @@ -1438,8 +1425,8 @@ static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
> >         page->mapping = NULL;
> >
> >         if (current->reclaim_state)
> > -               current->reclaim_state->reclaimed_slab += nr_freed;
> > -       memcg_uncharge_slab(page, order, cachep);
> > +               current->reclaim_state->reclaimed_slab += 1 << order;
> > +       uncharge_slab_page(page, order, cachep);
> >         __free_pages(page, order);
> >  }
> >
> > diff --git a/mm/slab.h b/mm/slab.h
> > index 4a261c97c138..0f5c5444acf1 100644
> > --- a/mm/slab.h
> > +++ b/mm/slab.h
> > @@ -205,6 +205,12 @@ ssize_t slabinfo_write(struct file *file, const char __user *buffer,
> >  void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
> >  int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
> >
> > +static inline int cache_vmstat_idx(struct kmem_cache *s)
> > +{
> > +       return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
> > +               NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE;
> > +}
> > +
> >  #ifdef CONFIG_MEMCG_KMEM
> >
> >  /* List of all root caches. */
> > @@ -352,6 +358,22 @@ static inline void memcg_link_cache(struct kmem_cache *s,
> >
> >  #endif /* CONFIG_MEMCG_KMEM */
> >
> > +static __always_inline int charge_slab_page(struct page *page,
> > +                                           gfp_t gfp, int order,
> > +                                           struct kmem_cache *s)
> > +{
> > +       memcg_charge_slab(page, gfp, order, s);
> 
> This does not seem right. Why the return of memcg_charge_slab is ignored?

Hi Shakeel!

Right, it's a bug. It's actually fixed later in the patchset
(in "mm: rework non-root kmem_cache lifecycle management"),
so the final result looks correct to me. Anyway, I'll fix it.

How does everything else look to you?

Thank you!
Shakeel Butt April 24, 2019, 7:40 p.m. UTC | #3
On Wed, Apr 24, 2019 at 12:17 PM Roman Gushchin <guro@fb.com> wrote:
>
> On Wed, Apr 24, 2019 at 10:23:45AM -0700, Shakeel Butt wrote:
> > Hi Roman,
> >
> > On Tue, Apr 23, 2019 at 9:30 PM Roman Gushchin <guro@fb.com> wrote:
> > >
> > > Currently the page accounting code is duplicated in SLAB and SLUB
> > > internals. Let's move it into new (un)charge_slab_page helpers
> > > in the slab_common.c file. These helpers will be responsible
> > > for statistics (global and memcg-aware) and memcg charging.
> > > So they are replacing direct memcg_(un)charge_slab() calls.
> > >
> > > Signed-off-by: Roman Gushchin <guro@fb.com>
> > > ---
> > >  mm/slab.c | 19 +++----------------
> > >  mm/slab.h | 22 ++++++++++++++++++++++
> > >  mm/slub.c | 14 ++------------
> > >  3 files changed, 27 insertions(+), 28 deletions(-)
> > >
> > > diff --git a/mm/slab.c b/mm/slab.c
> > > index 14466a73d057..53e6b2687102 100644
> > > --- a/mm/slab.c
> > > +++ b/mm/slab.c
> > > @@ -1389,7 +1389,6 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
> > >                                                                 int nodeid)
> > >  {
> > >         struct page *page;
> > > -       int nr_pages;
> > >
> > >         flags |= cachep->allocflags;
> > >
> > > @@ -1399,17 +1398,11 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
> > >                 return NULL;
> > >         }
> > >
> > > -       if (memcg_charge_slab(page, flags, cachep->gfporder, cachep)) {
> > > +       if (charge_slab_page(page, flags, cachep->gfporder, cachep)) {
> > >                 __free_pages(page, cachep->gfporder);
> > >                 return NULL;
> > >         }
> > >
> > > -       nr_pages = (1 << cachep->gfporder);
> > > -       if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
> > > -               mod_lruvec_page_state(page, NR_SLAB_RECLAIMABLE, nr_pages);
> > > -       else
> > > -               mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE, nr_pages);
> > > -
> > >         __SetPageSlab(page);
> > >         /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */
> > >         if (sk_memalloc_socks() && page_is_pfmemalloc(page))
> > > @@ -1424,12 +1417,6 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
> > >  static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
> > >  {
> > >         int order = cachep->gfporder;
> > > -       unsigned long nr_freed = (1 << order);
> > > -
> > > -       if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
> > > -               mod_lruvec_page_state(page, NR_SLAB_RECLAIMABLE, -nr_freed);
> > > -       else
> > > -               mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE, -nr_freed);
> > >
> > >         BUG_ON(!PageSlab(page));
> > >         __ClearPageSlabPfmemalloc(page);
> > > @@ -1438,8 +1425,8 @@ static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
> > >         page->mapping = NULL;
> > >
> > >         if (current->reclaim_state)
> > > -               current->reclaim_state->reclaimed_slab += nr_freed;
> > > -       memcg_uncharge_slab(page, order, cachep);
> > > +               current->reclaim_state->reclaimed_slab += 1 << order;
> > > +       uncharge_slab_page(page, order, cachep);
> > >         __free_pages(page, order);
> > >  }
> > >
> > > diff --git a/mm/slab.h b/mm/slab.h
> > > index 4a261c97c138..0f5c5444acf1 100644
> > > --- a/mm/slab.h
> > > +++ b/mm/slab.h
> > > @@ -205,6 +205,12 @@ ssize_t slabinfo_write(struct file *file, const char __user *buffer,
> > >  void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
> > >  int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
> > >
> > > +static inline int cache_vmstat_idx(struct kmem_cache *s)
> > > +{
> > > +       return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
> > > +               NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE;
> > > +}
> > > +
> > >  #ifdef CONFIG_MEMCG_KMEM
> > >
> > >  /* List of all root caches. */
> > > @@ -352,6 +358,22 @@ static inline void memcg_link_cache(struct kmem_cache *s,
> > >
> > >  #endif /* CONFIG_MEMCG_KMEM */
> > >
> > > +static __always_inline int charge_slab_page(struct page *page,
> > > +                                           gfp_t gfp, int order,
> > > +                                           struct kmem_cache *s)
> > > +{
> > > +       memcg_charge_slab(page, gfp, order, s);
> >
> > This does not seem right. Why the return of memcg_charge_slab is ignored?
>
> Hi Shakeel!
>
> Right, it's a bug. It's actually fixed later in the patchset
> (in "mm: rework non-root kmem_cache lifecycle management"),
> so the final result looks correct to me. Anyway, I'll fix it.
>
> How does everything else look to you?
>
> Thank you!

I caught this during quick glance. Another high level issue I found is
breakage of /proc/kpagecgroup for the slab pages which is easy to fix.

At the moment I am kind of stuck on some other stuff but will get back
to this in a week or so.

Shakeel
Roman Gushchin April 24, 2019, 7:51 p.m. UTC | #4
On Wed, Apr 24, 2019 at 12:40:59PM -0700, Shakeel Butt wrote:
> On Wed, Apr 24, 2019 at 12:17 PM Roman Gushchin <guro@fb.com> wrote:
> >
> > On Wed, Apr 24, 2019 at 10:23:45AM -0700, Shakeel Butt wrote:
> > > Hi Roman,
> > >
> > > On Tue, Apr 23, 2019 at 9:30 PM Roman Gushchin <guro@fb.com> wrote:
> > > >
> > > > Currently the page accounting code is duplicated in SLAB and SLUB
> > > > internals. Let's move it into new (un)charge_slab_page helpers
> > > > in the slab_common.c file. These helpers will be responsible
> > > > for statistics (global and memcg-aware) and memcg charging.
> > > > So they are replacing direct memcg_(un)charge_slab() calls.
> > > >
> > > > Signed-off-by: Roman Gushchin <guro@fb.com>
> > > > ---
> > > >  mm/slab.c | 19 +++----------------
> > > >  mm/slab.h | 22 ++++++++++++++++++++++
> > > >  mm/slub.c | 14 ++------------
> > > >  3 files changed, 27 insertions(+), 28 deletions(-)
> > > >
> > > > diff --git a/mm/slab.c b/mm/slab.c
> > > > index 14466a73d057..53e6b2687102 100644
> > > > --- a/mm/slab.c
> > > > +++ b/mm/slab.c
> > > > @@ -1389,7 +1389,6 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
> > > >                                                                 int nodeid)
> > > >  {
> > > >         struct page *page;
> > > > -       int nr_pages;
> > > >
> > > >         flags |= cachep->allocflags;
> > > >
> > > > @@ -1399,17 +1398,11 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
> > > >                 return NULL;
> > > >         }
> > > >
> > > > -       if (memcg_charge_slab(page, flags, cachep->gfporder, cachep)) {
> > > > +       if (charge_slab_page(page, flags, cachep->gfporder, cachep)) {
> > > >                 __free_pages(page, cachep->gfporder);
> > > >                 return NULL;
> > > >         }
> > > >
> > > > -       nr_pages = (1 << cachep->gfporder);
> > > > -       if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
> > > > -               mod_lruvec_page_state(page, NR_SLAB_RECLAIMABLE, nr_pages);
> > > > -       else
> > > > -               mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE, nr_pages);
> > > > -
> > > >         __SetPageSlab(page);
> > > >         /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */
> > > >         if (sk_memalloc_socks() && page_is_pfmemalloc(page))
> > > > @@ -1424,12 +1417,6 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
> > > >  static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
> > > >  {
> > > >         int order = cachep->gfporder;
> > > > -       unsigned long nr_freed = (1 << order);
> > > > -
> > > > -       if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
> > > > -               mod_lruvec_page_state(page, NR_SLAB_RECLAIMABLE, -nr_freed);
> > > > -       else
> > > > -               mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE, -nr_freed);
> > > >
> > > >         BUG_ON(!PageSlab(page));
> > > >         __ClearPageSlabPfmemalloc(page);
> > > > @@ -1438,8 +1425,8 @@ static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
> > > >         page->mapping = NULL;
> > > >
> > > >         if (current->reclaim_state)
> > > > -               current->reclaim_state->reclaimed_slab += nr_freed;
> > > > -       memcg_uncharge_slab(page, order, cachep);
> > > > +               current->reclaim_state->reclaimed_slab += 1 << order;
> > > > +       uncharge_slab_page(page, order, cachep);
> > > >         __free_pages(page, order);
> > > >  }
> > > >
> > > > diff --git a/mm/slab.h b/mm/slab.h
> > > > index 4a261c97c138..0f5c5444acf1 100644
> > > > --- a/mm/slab.h
> > > > +++ b/mm/slab.h
> > > > @@ -205,6 +205,12 @@ ssize_t slabinfo_write(struct file *file, const char __user *buffer,
> > > >  void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
> > > >  int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
> > > >
> > > > +static inline int cache_vmstat_idx(struct kmem_cache *s)
> > > > +{
> > > > +       return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
> > > > +               NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE;
> > > > +}
> > > > +
> > > >  #ifdef CONFIG_MEMCG_KMEM
> > > >
> > > >  /* List of all root caches. */
> > > > @@ -352,6 +358,22 @@ static inline void memcg_link_cache(struct kmem_cache *s,
> > > >
> > > >  #endif /* CONFIG_MEMCG_KMEM */
> > > >
> > > > +static __always_inline int charge_slab_page(struct page *page,
> > > > +                                           gfp_t gfp, int order,
> > > > +                                           struct kmem_cache *s)
> > > > +{
> > > > +       memcg_charge_slab(page, gfp, order, s);
> > >
> > > This does not seem right. Why the return of memcg_charge_slab is ignored?
> >
> > Hi Shakeel!
> >
> > Right, it's a bug. It's actually fixed later in the patchset
> > (in "mm: rework non-root kmem_cache lifecycle management"),
> > so the final result looks correct to me. Anyway, I'll fix it.
> >
> > How does everything else look to you?
> >
> > Thank you!
> 
> I caught this during quick glance. Another high level issue I found is
> breakage of /proc/kpagecgroup for the slab pages which is easy to fix.

Good point! I'll add it in the next iteration.

> 
> At the moment I am kind of stuck on some other stuff but will get back
> to this in a week or so.

I'm looking forward then... I'm also repeating my long-term test with this
iteration, and I'll have updated results in few days.

Thank you for looking into it!

Roman
diff mbox series

Patch

diff --git a/mm/slab.c b/mm/slab.c
index 14466a73d057..53e6b2687102 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1389,7 +1389,6 @@  static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
 								int nodeid)
 {
 	struct page *page;
-	int nr_pages;
 
 	flags |= cachep->allocflags;
 
@@ -1399,17 +1398,11 @@  static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
 		return NULL;
 	}
 
-	if (memcg_charge_slab(page, flags, cachep->gfporder, cachep)) {
+	if (charge_slab_page(page, flags, cachep->gfporder, cachep)) {
 		__free_pages(page, cachep->gfporder);
 		return NULL;
 	}
 
-	nr_pages = (1 << cachep->gfporder);
-	if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
-		mod_lruvec_page_state(page, NR_SLAB_RECLAIMABLE, nr_pages);
-	else
-		mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE, nr_pages);
-
 	__SetPageSlab(page);
 	/* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */
 	if (sk_memalloc_socks() && page_is_pfmemalloc(page))
@@ -1424,12 +1417,6 @@  static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
 static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
 {
 	int order = cachep->gfporder;
-	unsigned long nr_freed = (1 << order);
-
-	if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
-		mod_lruvec_page_state(page, NR_SLAB_RECLAIMABLE, -nr_freed);
-	else
-		mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE, -nr_freed);
 
 	BUG_ON(!PageSlab(page));
 	__ClearPageSlabPfmemalloc(page);
@@ -1438,8 +1425,8 @@  static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
 	page->mapping = NULL;
 
 	if (current->reclaim_state)
-		current->reclaim_state->reclaimed_slab += nr_freed;
-	memcg_uncharge_slab(page, order, cachep);
+		current->reclaim_state->reclaimed_slab += 1 << order;
+	uncharge_slab_page(page, order, cachep);
 	__free_pages(page, order);
 }
 
diff --git a/mm/slab.h b/mm/slab.h
index 4a261c97c138..0f5c5444acf1 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -205,6 +205,12 @@  ssize_t slabinfo_write(struct file *file, const char __user *buffer,
 void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
 int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
 
+static inline int cache_vmstat_idx(struct kmem_cache *s)
+{
+	return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
+		NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE;
+}
+
 #ifdef CONFIG_MEMCG_KMEM
 
 /* List of all root caches. */
@@ -352,6 +358,22 @@  static inline void memcg_link_cache(struct kmem_cache *s,
 
 #endif /* CONFIG_MEMCG_KMEM */
 
+static __always_inline int charge_slab_page(struct page *page,
+					    gfp_t gfp, int order,
+					    struct kmem_cache *s)
+{
+	memcg_charge_slab(page, gfp, order, s);
+	mod_lruvec_page_state(page, cache_vmstat_idx(s), 1 << order);
+	return 0;
+}
+
+static __always_inline void uncharge_slab_page(struct page *page, int order,
+					       struct kmem_cache *s)
+{
+	mod_lruvec_page_state(page, cache_vmstat_idx(s), -(1 << order));
+	memcg_uncharge_slab(page, order, s);
+}
+
 static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
 {
 	struct kmem_cache *cachep;
diff --git a/mm/slub.c b/mm/slub.c
index 195f61785c7d..90563c0b3b5f 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1499,7 +1499,7 @@  static inline struct page *alloc_slab_page(struct kmem_cache *s,
 	else
 		page = __alloc_pages_node(node, flags, order);
 
-	if (page && memcg_charge_slab(page, flags, order, s)) {
+	if (page && charge_slab_page(page, flags, order, s)) {
 		__free_pages(page, order);
 		page = NULL;
 	}
@@ -1692,11 +1692,6 @@  static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
 	if (!page)
 		return NULL;
 
-	mod_lruvec_page_state(page,
-		(s->flags & SLAB_RECLAIM_ACCOUNT) ?
-		NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
-		1 << oo_order(oo));
-
 	inc_slabs_node(s, page_to_nid(page), page->objects);
 
 	return page;
@@ -1730,18 +1725,13 @@  static void __free_slab(struct kmem_cache *s, struct page *page)
 			check_object(s, page, p, SLUB_RED_INACTIVE);
 	}
 
-	mod_lruvec_page_state(page,
-		(s->flags & SLAB_RECLAIM_ACCOUNT) ?
-		NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
-		-pages);
-
 	__ClearPageSlabPfmemalloc(page);
 	__ClearPageSlab(page);
 
 	page->mapping = NULL;
 	if (current->reclaim_state)
 		current->reclaim_state->reclaimed_slab += pages;
-	memcg_uncharge_slab(page, order, s);
+	uncharge_slab_page(page, order, s);
 	__free_pages(page, order);
 }