| Message ID | 1565144277-36240-5-git-send-email-yang.shi@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Make deferred split shrinker memcg aware | expand |
On 07.08.2019 05:17, Yang Shi wrote: > Currently THP deferred split shrinker is not memcg aware, this may cause > premature OOM with some configuration. For example the below test would > run into premature OOM easily: > > $ cgcreate -g memory:thp > $ echo 4G > /sys/fs/cgroup/memory/thp/memory/limit_in_bytes > $ cgexec -g memory:thp transhuge-stress 4000 > > transhuge-stress comes from kernel selftest. > > It is easy to hit OOM, but there are still a lot THP on the deferred > split queue, memcg direct reclaim can't touch them since the deferred > split shrinker is not memcg aware. > > Convert deferred split shrinker memcg aware by introducing per memcg > deferred split queue. The THP should be on either per node or per memcg > deferred split queue if it belongs to a memcg. When the page is > immigrated to the other memcg, it will be immigrated to the target > memcg's deferred split queue too. > > Reuse the second tail page's deferred_list for per memcg list since the > same THP can't be on multiple deferred split queues. > > Cc: Kirill Tkhai <ktkhai@virtuozzo.com> > Cc: Johannes Weiner <hannes@cmpxchg.org> > Cc: Michal Hocko <mhocko@suse.com> > Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> > Cc: Hugh Dickins <hughd@google.com> > Cc: Shakeel Butt <shakeelb@google.com> > Cc: David Rientjes <rientjes@google.com> > Cc: Qian Cai <cai@lca.pw> > Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com> But, please, see below one small suggestion. > --- > include/linux/huge_mm.h | 9 ++++++ > include/linux/memcontrol.h | 4 +++ > include/linux/mm_types.h | 1 + > mm/huge_memory.c | 76 +++++++++++++++++++++++++++++++++++++++------- > mm/memcontrol.c | 24 +++++++++++++++ > 5 files changed, 103 insertions(+), 11 deletions(-) > > diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h > index 45ede62..61c9ffd 100644 > --- a/include/linux/huge_mm.h > +++ b/include/linux/huge_mm.h > @@ -267,6 +267,15 @@ static inline bool thp_migration_supported(void) > return IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION); > } > > +static inline struct list_head *page_deferred_list(struct page *page) > +{ > + /* > + * Global or memcg deferred list in the second tail pages is > + * occupied by compound_head. > + */ > + return &page[2].deferred_list; > +} > + > #else /* CONFIG_TRANSPARENT_HUGEPAGE */ > #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; }) > #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; }) > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h > index 5771816..cace365 100644 > --- a/include/linux/memcontrol.h > +++ b/include/linux/memcontrol.h > @@ -312,6 +312,10 @@ struct mem_cgroup { > struct list_head event_list; > spinlock_t event_list_lock; > > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE > + struct deferred_split deferred_split_queue; > +#endif > + > struct mem_cgroup_per_node *nodeinfo[0]; > /* WARNING: nodeinfo must be the last member here */ > }; > diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h > index 3a37a89..156640c 100644 > --- a/include/linux/mm_types.h > +++ b/include/linux/mm_types.h > @@ -139,6 +139,7 @@ struct page { > struct { /* Second tail page of compound page */ > unsigned long _compound_pad_1; /* compound_head */ > unsigned long _compound_pad_2; > + /* For both global and memcg */ > struct list_head deferred_list; > }; > struct { /* Page table pages */ > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index e0d8e08..c9a596e 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -495,11 +495,25 @@ pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) > return pmd; > } > > -static inline struct list_head *page_deferred_list(struct page *page) > +#ifdef CONFIG_MEMCG > +static inline struct deferred_split *get_deferred_split_queue(struct page *page) > { > - /* ->lru in the tail pages is occupied by compound_head. */ > - return &page[2].deferred_list; > + struct mem_cgroup *memcg = compound_head(page)->mem_cgroup; > + struct pglist_data *pgdat = NODE_DATA(page_to_nid(page)); > + > + if (memcg) > + return &memcg->deferred_split_queue; > + else > + return &pgdat->deferred_split_queue; > +} > +#else > +static inline struct deferred_split *get_deferred_split_queue(struct page *page) > +{ > + struct pglist_data *pgdat = NODE_DATA(page_to_nid(page)); > + > + return &pgdat->deferred_split_queue; > } > +#endif > > void prep_transhuge_page(struct page *page) > { > @@ -2658,7 +2672,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) > { > struct page *head = compound_head(page); > struct pglist_data *pgdata = NODE_DATA(page_to_nid(head)); > - struct deferred_split *ds_queue = &pgdata->deferred_split_queue; > + struct deferred_split *ds_queue = get_deferred_split_queue(page); > struct anon_vma *anon_vma = NULL; > struct address_space *mapping = NULL; > int count, mapcount, extra_pins, ret; > @@ -2794,8 +2808,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) > > void free_transhuge_page(struct page *page) > { > - struct pglist_data *pgdata = NODE_DATA(page_to_nid(page)); > - struct deferred_split *ds_queue = &pgdata->deferred_split_queue; > + struct deferred_split *ds_queue = get_deferred_split_queue(page); > unsigned long flags; > > spin_lock_irqsave(&ds_queue->split_queue_lock, flags); > @@ -2809,17 +2822,37 @@ void free_transhuge_page(struct page *page) > > void deferred_split_huge_page(struct page *page) > { > - struct pglist_data *pgdata = NODE_DATA(page_to_nid(page)); > - struct deferred_split *ds_queue = &pgdata->deferred_split_queue; > + struct deferred_split *ds_queue = get_deferred_split_queue(page); > +#ifdef CONFIG_MEMCG > + struct mem_cgroup *memcg = compound_head(page)->mem_cgroup; > +#endif > unsigned long flags; > > VM_BUG_ON_PAGE(!PageTransHuge(page), page); > > + /* > + * The try_to_unmap() in page reclaim path might reach here too, > + * this may cause a race condition to corrupt deferred split queue. > + * And, if page reclaim is already handling the same page, it is > + * unnecessary to handle it again in shrinker. > + * > + * Check PageSwapCache to determine if the page is being > + * handled by page reclaim since THP swap would add the page into > + * swap cache before calling try_to_unmap(). > + */ > + if (PageSwapCache(page)) > + return; > + > spin_lock_irqsave(&ds_queue->split_queue_lock, flags); > if (list_empty(page_deferred_list(page))) { > count_vm_event(THP_DEFERRED_SPLIT_PAGE); > list_add_tail(page_deferred_list(page), &ds_queue->split_queue); > ds_queue->split_queue_len++; > +#ifdef CONFIG_MEMCG > + if (memcg) > + memcg_set_shrinker_bit(memcg, page_to_nid(page), > + deferred_split_shrinker.id); > +#endif > } > spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags); > } > @@ -2827,8 +2860,19 @@ void deferred_split_huge_page(struct page *page) > static unsigned long deferred_split_count(struct shrinker *shrink, > struct shrink_control *sc) > { > + struct deferred_split *ds_queue; > struct pglist_data *pgdata = NODE_DATA(sc->nid); > - struct deferred_split *ds_queue = &pgdata->deferred_split_queue; > + > +#ifdef CONFIG_MEMCG > + if (!sc->memcg) { > + ds_queue = &pgdata->deferred_split_queue; > + return READ_ONCE(ds_queue->split_queue_len); > + } > + > + ds_queue = &sc->memcg->deferred_split_queue; > +#else > + ds_queue = &pgdata->deferred_split_queue; > +#endif > return READ_ONCE(ds_queue->split_queue_len); > } Can we write this a little more compact? struct deferred_split *ds_queue = &pgdata->deferred_split_queue; #ifdef CONFIG_MEMCG if (sc->memcg) ds_queue = &sc->memcg->deferred_split_queue; #endif Or just introduce a helper (something like get_sc_deferred_split_queue). The same is in .scan method. > > @@ -2836,12 +2880,21 @@ static unsigned long deferred_split_scan(struct shrinker *shrink, > struct shrink_control *sc) > { > struct pglist_data *pgdata = NODE_DATA(sc->nid); > - struct deferred_split *ds_queue = &pgdata->deferred_split_queue; > + struct deferred_split *ds_queue; > unsigned long flags; > LIST_HEAD(list), *pos, *next; > struct page *page; > int split = 0; > > +#ifdef CONFIG_MEMCG > + if (sc->memcg) > + ds_queue = &sc->memcg->deferred_split_queue; > + else > + ds_queue = &pgdata->deferred_split_queue; > +#else > + ds_queue = &pgdata->deferred_split_queue; > +#endif > + > spin_lock_irqsave(&ds_queue->split_queue_lock, flags); > /* Take pin on all head pages to avoid freeing them under us */ > list_for_each_safe(pos, next, &ds_queue->split_queue) { > @@ -2888,7 +2941,8 @@ static unsigned long deferred_split_scan(struct shrinker *shrink, > .count_objects = deferred_split_count, > .scan_objects = deferred_split_scan, > .seeks = DEFAULT_SEEKS, > - .flags = SHRINKER_NUMA_AWARE, > + .flags = SHRINKER_NUMA_AWARE | SHRINKER_MEMCG_AWARE | > + SHRINKER_NONSLAB, > }; > > #ifdef CONFIG_DEBUG_FS > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index d90ded1..da4a411 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -4698,6 +4698,11 @@ static struct mem_cgroup *mem_cgroup_alloc(void) > #ifdef CONFIG_CGROUP_WRITEBACK > INIT_LIST_HEAD(&memcg->cgwb_list); > #endif > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE > + spin_lock_init(&memcg->deferred_split_queue.split_queue_lock); > + INIT_LIST_HEAD(&memcg->deferred_split_queue.split_queue); > + memcg->deferred_split_queue.split_queue_len = 0; > +#endif > idr_replace(&mem_cgroup_idr, memcg, memcg->id.id); > return memcg; > fail: > @@ -5071,6 +5076,14 @@ static int mem_cgroup_move_account(struct page *page, > __mod_memcg_state(to, NR_WRITEBACK, nr_pages); > } > > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE > + if (compound && !list_empty(page_deferred_list(page))) { > + spin_lock(&from->deferred_split_queue.split_queue_lock); > + list_del_init(page_deferred_list(page)); > + from->deferred_split_queue.split_queue_len--; > + spin_unlock(&from->deferred_split_queue.split_queue_lock); > + } > +#endif > /* > * It is safe to change page->mem_cgroup here because the page > * is referenced, charged, and isolated - we can't race with > @@ -5079,6 +5092,17 @@ static int mem_cgroup_move_account(struct page *page, > > /* caller should have done css_get */ > page->mem_cgroup = to; > + > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE > + if (compound && list_empty(page_deferred_list(page))) { > + spin_lock(&to->deferred_split_queue.split_queue_lock); > + list_add_tail(page_deferred_list(page), > + &to->deferred_split_queue.split_queue); > + to->deferred_split_queue.split_queue_len++; > + spin_unlock(&to->deferred_split_queue.split_queue_lock); > + } > +#endif > + > spin_unlock_irqrestore(&from->move_lock, flags); > > ret = 0; >
On 8/20/19 4:06 AM, Kirill Tkhai wrote: > On 07.08.2019 05:17, Yang Shi wrote: >> Currently THP deferred split shrinker is not memcg aware, this may cause >> premature OOM with some configuration. For example the below test would >> run into premature OOM easily: >> >> $ cgcreate -g memory:thp >> $ echo 4G > /sys/fs/cgroup/memory/thp/memory/limit_in_bytes >> $ cgexec -g memory:thp transhuge-stress 4000 >> >> transhuge-stress comes from kernel selftest. >> >> It is easy to hit OOM, but there are still a lot THP on the deferred >> split queue, memcg direct reclaim can't touch them since the deferred >> split shrinker is not memcg aware. >> >> Convert deferred split shrinker memcg aware by introducing per memcg >> deferred split queue. The THP should be on either per node or per memcg >> deferred split queue if it belongs to a memcg. When the page is >> immigrated to the other memcg, it will be immigrated to the target >> memcg's deferred split queue too. >> >> Reuse the second tail page's deferred_list for per memcg list since the >> same THP can't be on multiple deferred split queues. >> >> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> >> Cc: Johannes Weiner <hannes@cmpxchg.org> >> Cc: Michal Hocko <mhocko@suse.com> >> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> >> Cc: Hugh Dickins <hughd@google.com> >> Cc: Shakeel Butt <shakeelb@google.com> >> Cc: David Rientjes <rientjes@google.com> >> Cc: Qian Cai <cai@lca.pw> >> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> >> Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> > Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com> > > But, please, see below one small suggestion. > >> --- >> include/linux/huge_mm.h | 9 ++++++ >> include/linux/memcontrol.h | 4 +++ >> include/linux/mm_types.h | 1 + >> mm/huge_memory.c | 76 +++++++++++++++++++++++++++++++++++++++------- >> mm/memcontrol.c | 24 +++++++++++++++ >> 5 files changed, 103 insertions(+), 11 deletions(-) >> >> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h >> index 45ede62..61c9ffd 100644 >> --- a/include/linux/huge_mm.h >> +++ b/include/linux/huge_mm.h >> @@ -267,6 +267,15 @@ static inline bool thp_migration_supported(void) >> return IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION); >> } >> >> +static inline struct list_head *page_deferred_list(struct page *page) >> +{ >> + /* >> + * Global or memcg deferred list in the second tail pages is >> + * occupied by compound_head. >> + */ >> + return &page[2].deferred_list; >> +} >> + >> #else /* CONFIG_TRANSPARENT_HUGEPAGE */ >> #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; }) >> #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; }) >> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h >> index 5771816..cace365 100644 >> --- a/include/linux/memcontrol.h >> +++ b/include/linux/memcontrol.h >> @@ -312,6 +312,10 @@ struct mem_cgroup { >> struct list_head event_list; >> spinlock_t event_list_lock; >> >> +#ifdef CONFIG_TRANSPARENT_HUGEPAGE >> + struct deferred_split deferred_split_queue; >> +#endif >> + >> struct mem_cgroup_per_node *nodeinfo[0]; >> /* WARNING: nodeinfo must be the last member here */ >> }; >> diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h >> index 3a37a89..156640c 100644 >> --- a/include/linux/mm_types.h >> +++ b/include/linux/mm_types.h >> @@ -139,6 +139,7 @@ struct page { >> struct { /* Second tail page of compound page */ >> unsigned long _compound_pad_1; /* compound_head */ >> unsigned long _compound_pad_2; >> + /* For both global and memcg */ >> struct list_head deferred_list; >> }; >> struct { /* Page table pages */ >> diff --git a/mm/huge_memory.c b/mm/huge_memory.c >> index e0d8e08..c9a596e 100644 >> --- a/mm/huge_memory.c >> +++ b/mm/huge_memory.c >> @@ -495,11 +495,25 @@ pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) >> return pmd; >> } >> >> -static inline struct list_head *page_deferred_list(struct page *page) >> +#ifdef CONFIG_MEMCG >> +static inline struct deferred_split *get_deferred_split_queue(struct page *page) >> { >> - /* ->lru in the tail pages is occupied by compound_head. */ >> - return &page[2].deferred_list; >> + struct mem_cgroup *memcg = compound_head(page)->mem_cgroup; >> + struct pglist_data *pgdat = NODE_DATA(page_to_nid(page)); >> + >> + if (memcg) >> + return &memcg->deferred_split_queue; >> + else >> + return &pgdat->deferred_split_queue; >> +} >> +#else >> +static inline struct deferred_split *get_deferred_split_queue(struct page *page) >> +{ >> + struct pglist_data *pgdat = NODE_DATA(page_to_nid(page)); >> + >> + return &pgdat->deferred_split_queue; >> } >> +#endif >> >> void prep_transhuge_page(struct page *page) >> { >> @@ -2658,7 +2672,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) >> { >> struct page *head = compound_head(page); >> struct pglist_data *pgdata = NODE_DATA(page_to_nid(head)); >> - struct deferred_split *ds_queue = &pgdata->deferred_split_queue; >> + struct deferred_split *ds_queue = get_deferred_split_queue(page); >> struct anon_vma *anon_vma = NULL; >> struct address_space *mapping = NULL; >> int count, mapcount, extra_pins, ret; >> @@ -2794,8 +2808,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) >> >> void free_transhuge_page(struct page *page) >> { >> - struct pglist_data *pgdata = NODE_DATA(page_to_nid(page)); >> - struct deferred_split *ds_queue = &pgdata->deferred_split_queue; >> + struct deferred_split *ds_queue = get_deferred_split_queue(page); >> unsigned long flags; >> >> spin_lock_irqsave(&ds_queue->split_queue_lock, flags); >> @@ -2809,17 +2822,37 @@ void free_transhuge_page(struct page *page) >> >> void deferred_split_huge_page(struct page *page) >> { >> - struct pglist_data *pgdata = NODE_DATA(page_to_nid(page)); >> - struct deferred_split *ds_queue = &pgdata->deferred_split_queue; >> + struct deferred_split *ds_queue = get_deferred_split_queue(page); >> +#ifdef CONFIG_MEMCG >> + struct mem_cgroup *memcg = compound_head(page)->mem_cgroup; >> +#endif >> unsigned long flags; >> >> VM_BUG_ON_PAGE(!PageTransHuge(page), page); >> >> + /* >> + * The try_to_unmap() in page reclaim path might reach here too, >> + * this may cause a race condition to corrupt deferred split queue. >> + * And, if page reclaim is already handling the same page, it is >> + * unnecessary to handle it again in shrinker. >> + * >> + * Check PageSwapCache to determine if the page is being >> + * handled by page reclaim since THP swap would add the page into >> + * swap cache before calling try_to_unmap(). >> + */ >> + if (PageSwapCache(page)) >> + return; >> + >> spin_lock_irqsave(&ds_queue->split_queue_lock, flags); >> if (list_empty(page_deferred_list(page))) { >> count_vm_event(THP_DEFERRED_SPLIT_PAGE); >> list_add_tail(page_deferred_list(page), &ds_queue->split_queue); >> ds_queue->split_queue_len++; >> +#ifdef CONFIG_MEMCG >> + if (memcg) >> + memcg_set_shrinker_bit(memcg, page_to_nid(page), >> + deferred_split_shrinker.id); >> +#endif >> } >> spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags); >> } >> @@ -2827,8 +2860,19 @@ void deferred_split_huge_page(struct page *page) >> static unsigned long deferred_split_count(struct shrinker *shrink, >> struct shrink_control *sc) >> { >> + struct deferred_split *ds_queue; >> struct pglist_data *pgdata = NODE_DATA(sc->nid); >> - struct deferred_split *ds_queue = &pgdata->deferred_split_queue; >> + >> +#ifdef CONFIG_MEMCG >> + if (!sc->memcg) { >> + ds_queue = &pgdata->deferred_split_queue; >> + return READ_ONCE(ds_queue->split_queue_len); >> + } >> + >> + ds_queue = &sc->memcg->deferred_split_queue; >> +#else >> + ds_queue = &pgdata->deferred_split_queue; >> +#endif >> return READ_ONCE(ds_queue->split_queue_len); >> } > Can we write this a little more compact? > > struct deferred_split *ds_queue = &pgdata->deferred_split_queue; > > #ifdef CONFIG_MEMCG > if (sc->memcg) > ds_queue = &sc->memcg->deferred_split_queue; > #endif Yes, sure. > > Or just introduce a helper (something like get_sc_deferred_split_queue). > The same is in .scan method. A helper sounds fine too, but IMHO I don't see to much benefit since just _count and _scan would call them. > >> >> @@ -2836,12 +2880,21 @@ static unsigned long deferred_split_scan(struct shrinker *shrink, >> struct shrink_control *sc) >> { >> struct pglist_data *pgdata = NODE_DATA(sc->nid); >> - struct deferred_split *ds_queue = &pgdata->deferred_split_queue; >> + struct deferred_split *ds_queue; >> unsigned long flags; >> LIST_HEAD(list), *pos, *next; >> struct page *page; >> int split = 0; >> >> +#ifdef CONFIG_MEMCG >> + if (sc->memcg) >> + ds_queue = &sc->memcg->deferred_split_queue; >> + else >> + ds_queue = &pgdata->deferred_split_queue; >> +#else >> + ds_queue = &pgdata->deferred_split_queue; >> +#endif >> + >> spin_lock_irqsave(&ds_queue->split_queue_lock, flags); >> /* Take pin on all head pages to avoid freeing them under us */ >> list_for_each_safe(pos, next, &ds_queue->split_queue) { >> @@ -2888,7 +2941,8 @@ static unsigned long deferred_split_scan(struct shrinker *shrink, >> .count_objects = deferred_split_count, >> .scan_objects = deferred_split_scan, >> .seeks = DEFAULT_SEEKS, >> - .flags = SHRINKER_NUMA_AWARE, >> + .flags = SHRINKER_NUMA_AWARE | SHRINKER_MEMCG_AWARE | >> + SHRINKER_NONSLAB, >> }; >> >> #ifdef CONFIG_DEBUG_FS >> diff --git a/mm/memcontrol.c b/mm/memcontrol.c >> index d90ded1..da4a411 100644 >> --- a/mm/memcontrol.c >> +++ b/mm/memcontrol.c >> @@ -4698,6 +4698,11 @@ static struct mem_cgroup *mem_cgroup_alloc(void) >> #ifdef CONFIG_CGROUP_WRITEBACK >> INIT_LIST_HEAD(&memcg->cgwb_list); >> #endif >> +#ifdef CONFIG_TRANSPARENT_HUGEPAGE >> + spin_lock_init(&memcg->deferred_split_queue.split_queue_lock); >> + INIT_LIST_HEAD(&memcg->deferred_split_queue.split_queue); >> + memcg->deferred_split_queue.split_queue_len = 0; >> +#endif >> idr_replace(&mem_cgroup_idr, memcg, memcg->id.id); >> return memcg; >> fail: >> @@ -5071,6 +5076,14 @@ static int mem_cgroup_move_account(struct page *page, >> __mod_memcg_state(to, NR_WRITEBACK, nr_pages); >> } >> >> +#ifdef CONFIG_TRANSPARENT_HUGEPAGE >> + if (compound && !list_empty(page_deferred_list(page))) { >> + spin_lock(&from->deferred_split_queue.split_queue_lock); >> + list_del_init(page_deferred_list(page)); >> + from->deferred_split_queue.split_queue_len--; >> + spin_unlock(&from->deferred_split_queue.split_queue_lock); >> + } >> +#endif >> /* >> * It is safe to change page->mem_cgroup here because the page >> * is referenced, charged, and isolated - we can't race with >> @@ -5079,6 +5092,17 @@ static int mem_cgroup_move_account(struct page *page, >> >> /* caller should have done css_get */ >> page->mem_cgroup = to; >> + >> +#ifdef CONFIG_TRANSPARENT_HUGEPAGE >> + if (compound && list_empty(page_deferred_list(page))) { >> + spin_lock(&to->deferred_split_queue.split_queue_lock); >> + list_add_tail(page_deferred_list(page), >> + &to->deferred_split_queue.split_queue); >> + to->deferred_split_queue.split_queue_len++; >> + spin_unlock(&to->deferred_split_queue.split_queue_lock); >> + } >> +#endif >> + >> spin_unlock_irqrestore(&from->move_lock, flags); >> >> ret = 0; >>
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 45ede62..61c9ffd 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -267,6 +267,15 @@ static inline bool thp_migration_supported(void) return IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION); } +static inline struct list_head *page_deferred_list(struct page *page) +{ + /* + * Global or memcg deferred list in the second tail pages is + * occupied by compound_head. + */ + return &page[2].deferred_list; +} + #else /* CONFIG_TRANSPARENT_HUGEPAGE */ #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; }) #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; }) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 5771816..cace365 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -312,6 +312,10 @@ struct mem_cgroup { struct list_head event_list; spinlock_t event_list_lock; +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + struct deferred_split deferred_split_queue; +#endif + struct mem_cgroup_per_node *nodeinfo[0]; /* WARNING: nodeinfo must be the last member here */ }; diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 3a37a89..156640c 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -139,6 +139,7 @@ struct page { struct { /* Second tail page of compound page */ unsigned long _compound_pad_1; /* compound_head */ unsigned long _compound_pad_2; + /* For both global and memcg */ struct list_head deferred_list; }; struct { /* Page table pages */ diff --git a/mm/huge_memory.c b/mm/huge_memory.c index e0d8e08..c9a596e 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -495,11 +495,25 @@ pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) return pmd; } -static inline struct list_head *page_deferred_list(struct page *page) +#ifdef CONFIG_MEMCG +static inline struct deferred_split *get_deferred_split_queue(struct page *page) { - /* ->lru in the tail pages is occupied by compound_head. */ - return &page[2].deferred_list; + struct mem_cgroup *memcg = compound_head(page)->mem_cgroup; + struct pglist_data *pgdat = NODE_DATA(page_to_nid(page)); + + if (memcg) + return &memcg->deferred_split_queue; + else + return &pgdat->deferred_split_queue; +} +#else +static inline struct deferred_split *get_deferred_split_queue(struct page *page) +{ + struct pglist_data *pgdat = NODE_DATA(page_to_nid(page)); + + return &pgdat->deferred_split_queue; } +#endif void prep_transhuge_page(struct page *page) { @@ -2658,7 +2672,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) { struct page *head = compound_head(page); struct pglist_data *pgdata = NODE_DATA(page_to_nid(head)); - struct deferred_split *ds_queue = &pgdata->deferred_split_queue; + struct deferred_split *ds_queue = get_deferred_split_queue(page); struct anon_vma *anon_vma = NULL; struct address_space *mapping = NULL; int count, mapcount, extra_pins, ret; @@ -2794,8 +2808,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) void free_transhuge_page(struct page *page) { - struct pglist_data *pgdata = NODE_DATA(page_to_nid(page)); - struct deferred_split *ds_queue = &pgdata->deferred_split_queue; + struct deferred_split *ds_queue = get_deferred_split_queue(page); unsigned long flags; spin_lock_irqsave(&ds_queue->split_queue_lock, flags); @@ -2809,17 +2822,37 @@ void free_transhuge_page(struct page *page) void deferred_split_huge_page(struct page *page) { - struct pglist_data *pgdata = NODE_DATA(page_to_nid(page)); - struct deferred_split *ds_queue = &pgdata->deferred_split_queue; + struct deferred_split *ds_queue = get_deferred_split_queue(page); +#ifdef CONFIG_MEMCG + struct mem_cgroup *memcg = compound_head(page)->mem_cgroup; +#endif unsigned long flags; VM_BUG_ON_PAGE(!PageTransHuge(page), page); + /* + * The try_to_unmap() in page reclaim path might reach here too, + * this may cause a race condition to corrupt deferred split queue. + * And, if page reclaim is already handling the same page, it is + * unnecessary to handle it again in shrinker. + * + * Check PageSwapCache to determine if the page is being + * handled by page reclaim since THP swap would add the page into + * swap cache before calling try_to_unmap(). + */ + if (PageSwapCache(page)) + return; + spin_lock_irqsave(&ds_queue->split_queue_lock, flags); if (list_empty(page_deferred_list(page))) { count_vm_event(THP_DEFERRED_SPLIT_PAGE); list_add_tail(page_deferred_list(page), &ds_queue->split_queue); ds_queue->split_queue_len++; +#ifdef CONFIG_MEMCG + if (memcg) + memcg_set_shrinker_bit(memcg, page_to_nid(page), + deferred_split_shrinker.id); +#endif } spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags); } @@ -2827,8 +2860,19 @@ void deferred_split_huge_page(struct page *page) static unsigned long deferred_split_count(struct shrinker *shrink, struct shrink_control *sc) { + struct deferred_split *ds_queue; struct pglist_data *pgdata = NODE_DATA(sc->nid); - struct deferred_split *ds_queue = &pgdata->deferred_split_queue; + +#ifdef CONFIG_MEMCG + if (!sc->memcg) { + ds_queue = &pgdata->deferred_split_queue; + return READ_ONCE(ds_queue->split_queue_len); + } + + ds_queue = &sc->memcg->deferred_split_queue; +#else + ds_queue = &pgdata->deferred_split_queue; +#endif return READ_ONCE(ds_queue->split_queue_len); } @@ -2836,12 +2880,21 @@ static unsigned long deferred_split_scan(struct shrinker *shrink, struct shrink_control *sc) { struct pglist_data *pgdata = NODE_DATA(sc->nid); - struct deferred_split *ds_queue = &pgdata->deferred_split_queue; + struct deferred_split *ds_queue; unsigned long flags; LIST_HEAD(list), *pos, *next; struct page *page; int split = 0; +#ifdef CONFIG_MEMCG + if (sc->memcg) + ds_queue = &sc->memcg->deferred_split_queue; + else + ds_queue = &pgdata->deferred_split_queue; +#else + ds_queue = &pgdata->deferred_split_queue; +#endif + spin_lock_irqsave(&ds_queue->split_queue_lock, flags); /* Take pin on all head pages to avoid freeing them under us */ list_for_each_safe(pos, next, &ds_queue->split_queue) { @@ -2888,7 +2941,8 @@ static unsigned long deferred_split_scan(struct shrinker *shrink, .count_objects = deferred_split_count, .scan_objects = deferred_split_scan, .seeks = DEFAULT_SEEKS, - .flags = SHRINKER_NUMA_AWARE, + .flags = SHRINKER_NUMA_AWARE | SHRINKER_MEMCG_AWARE | + SHRINKER_NONSLAB, }; #ifdef CONFIG_DEBUG_FS diff --git a/mm/memcontrol.c b/mm/memcontrol.c index d90ded1..da4a411 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4698,6 +4698,11 @@ static struct mem_cgroup *mem_cgroup_alloc(void) #ifdef CONFIG_CGROUP_WRITEBACK INIT_LIST_HEAD(&memcg->cgwb_list); #endif +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + spin_lock_init(&memcg->deferred_split_queue.split_queue_lock); + INIT_LIST_HEAD(&memcg->deferred_split_queue.split_queue); + memcg->deferred_split_queue.split_queue_len = 0; +#endif idr_replace(&mem_cgroup_idr, memcg, memcg->id.id); return memcg; fail: @@ -5071,6 +5076,14 @@ static int mem_cgroup_move_account(struct page *page, __mod_memcg_state(to, NR_WRITEBACK, nr_pages); } +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + if (compound && !list_empty(page_deferred_list(page))) { + spin_lock(&from->deferred_split_queue.split_queue_lock); + list_del_init(page_deferred_list(page)); + from->deferred_split_queue.split_queue_len--; + spin_unlock(&from->deferred_split_queue.split_queue_lock); + } +#endif /* * It is safe to change page->mem_cgroup here because the page * is referenced, charged, and isolated - we can't race with @@ -5079,6 +5092,17 @@ static int mem_cgroup_move_account(struct page *page, /* caller should have done css_get */ page->mem_cgroup = to; + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + if (compound && list_empty(page_deferred_list(page))) { + spin_lock(&to->deferred_split_queue.split_queue_lock); + list_add_tail(page_deferred_list(page), + &to->deferred_split_queue.split_queue); + to->deferred_split_queue.split_queue_len++; + spin_unlock(&to->deferred_split_queue.split_queue_lock); + } +#endif + spin_unlock_irqrestore(&from->move_lock, flags); ret = 0;