From: Jérôme Glisse <jglisse@xxxxxxxxxx> Subject: mm/memcontrol: allow to uncharge page without using page->lru field HMM pages (private or public device pages) are ZONE_DEVICE page and thus you can not use page->lru fields of those pages. This patch re-arrange the uncharge to allow single page to be uncharge without modifying the lru field of the struct page. There is no change to memcontrol logic, it is the same as it was before this patch. Link: http://lkml.kernel.org/r/20170817000548.32038-10-jglisse@xxxxxxxxxx Signed-off-by: Jérôme Glisse <jglisse@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> Cc: Aneesh Kumar <aneesh.kumar@xxxxxxxxxxxxxxxxxx> Cc: Balbir Singh <bsingharora@xxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: David Nellans <dnellans@xxxxxxxxxx> Cc: Evgeny Baskakov <ebaskakov@xxxxxxxxxx> Cc: John Hubbard <jhubbard@xxxxxxxxxx> Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Mark Hairgrove <mhairgrove@xxxxxxxxxx> Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> Cc: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> Cc: Sherry Cheung <SCheung@xxxxxxxxxx> Cc: Subhash Gutti <sgutti@xxxxxxxxxx> Cc: Bob Liu <liubo95@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memcontrol.c | 168 +++++++++++++++++++++++++--------------------- 1 file changed, 92 insertions(+), 76 deletions(-) diff -puN mm/memcontrol.c~mm-memcontrol-allow-to-uncharge-page-without-using-page-lru-field mm/memcontrol.c --- a/mm/memcontrol.c~mm-memcontrol-allow-to-uncharge-page-without-using-page-lru-field +++ a/mm/memcontrol.c @@ -5540,48 +5540,102 @@ void mem_cgroup_cancel_charge(struct pag cancel_charge(memcg, nr_pages); } -static void uncharge_batch(struct mem_cgroup *memcg, unsigned long pgpgout, - unsigned long nr_anon, unsigned long nr_file, - unsigned long nr_kmem, unsigned long nr_huge, - unsigned long nr_shmem, struct page *dummy_page) +struct uncharge_gather { + struct mem_cgroup *memcg; + unsigned long pgpgout; + unsigned long nr_anon; + unsigned long nr_file; + unsigned long nr_kmem; + unsigned long nr_huge; + unsigned long nr_shmem; + struct page *dummy_page; +}; + +static inline void uncharge_gather_clear(struct uncharge_gather *ug) +{ + memset(ug, 0, sizeof(*ug)); +} + +static void uncharge_batch(const struct uncharge_gather *ug) { - unsigned long nr_pages = nr_anon + nr_file + nr_kmem; + unsigned long nr_pages = ug->nr_anon + ug->nr_file + ug->nr_kmem; unsigned long flags; - if (!mem_cgroup_is_root(memcg)) { - page_counter_uncharge(&memcg->memory, nr_pages); + if (!mem_cgroup_is_root(ug->memcg)) { + page_counter_uncharge(&ug->memcg->memory, nr_pages); if (do_memsw_account()) - page_counter_uncharge(&memcg->memsw, nr_pages); - if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && nr_kmem) - page_counter_uncharge(&memcg->kmem, nr_kmem); - memcg_oom_recover(memcg); + page_counter_uncharge(&ug->memcg->memsw, nr_pages); + if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && ug->nr_kmem) + page_counter_uncharge(&ug->memcg->kmem, ug->nr_kmem); + memcg_oom_recover(ug->memcg); } local_irq_save(flags); - __this_cpu_sub(memcg->stat->count[MEMCG_RSS], nr_anon); - __this_cpu_sub(memcg->stat->count[MEMCG_CACHE], nr_file); - __this_cpu_sub(memcg->stat->count[MEMCG_RSS_HUGE], nr_huge); - __this_cpu_sub(memcg->stat->count[NR_SHMEM], nr_shmem); - __this_cpu_add(memcg->stat->events[PGPGOUT], pgpgout); - __this_cpu_add(memcg->stat->nr_page_events, nr_pages); - memcg_check_events(memcg, dummy_page); + __this_cpu_sub(ug->memcg->stat->count[MEMCG_RSS], ug->nr_anon); + __this_cpu_sub(ug->memcg->stat->count[MEMCG_CACHE], ug->nr_file); + __this_cpu_sub(ug->memcg->stat->count[MEMCG_RSS_HUGE], ug->nr_huge); + __this_cpu_sub(ug->memcg->stat->count[NR_SHMEM], ug->nr_shmem); + __this_cpu_add(ug->memcg->stat->events[PGPGOUT], ug->pgpgout); + __this_cpu_add(ug->memcg->stat->nr_page_events, nr_pages); + memcg_check_events(ug->memcg, ug->dummy_page); local_irq_restore(flags); - if (!mem_cgroup_is_root(memcg)) - css_put_many(&memcg->css, nr_pages); + if (!mem_cgroup_is_root(ug->memcg)) + css_put_many(&ug->memcg->css, nr_pages); +} + +static void uncharge_page(struct page *page, struct uncharge_gather *ug) +{ + VM_BUG_ON_PAGE(PageLRU(page), page); + VM_BUG_ON_PAGE(!PageHWPoison(page) && page_count(page), page); + + if (!page->mem_cgroup) + return; + + /* + * Nobody should be changing or seriously looking at + * page->mem_cgroup at this point, we have fully + * exclusive access to the page. + */ + + if (ug->memcg != page->mem_cgroup) { + if (ug->memcg) { + uncharge_batch(ug); + uncharge_gather_clear(ug); + } + ug->memcg = page->mem_cgroup; + } + + if (!PageKmemcg(page)) { + unsigned int nr_pages = 1; + + if (PageTransHuge(page)) { + nr_pages <<= compound_order(page); + ug->nr_huge += nr_pages; + } + if (PageAnon(page)) + ug->nr_anon += nr_pages; + else { + ug->nr_file += nr_pages; + if (PageSwapBacked(page)) + ug->nr_shmem += nr_pages; + } + ug->pgpgout++; + } else { + ug->nr_kmem += 1 << compound_order(page); + __ClearPageKmemcg(page); + } + + ug->dummy_page = page; + page->mem_cgroup = NULL; } static void uncharge_list(struct list_head *page_list) { - struct mem_cgroup *memcg = NULL; - unsigned long nr_shmem = 0; - unsigned long nr_anon = 0; - unsigned long nr_file = 0; - unsigned long nr_huge = 0; - unsigned long nr_kmem = 0; - unsigned long pgpgout = 0; + struct uncharge_gather ug; struct list_head *next; - struct page *page; + + uncharge_gather_clear(&ug); /* * Note that the list can be a single page->lru; hence the @@ -5589,57 +5643,16 @@ static void uncharge_list(struct list_he */ next = page_list->next; do { + struct page *page; + page = list_entry(next, struct page, lru); next = page->lru.next; - VM_BUG_ON_PAGE(PageLRU(page), page); - VM_BUG_ON_PAGE(!PageHWPoison(page) && page_count(page), page); - - if (!page->mem_cgroup) - continue; - - /* - * Nobody should be changing or seriously looking at - * page->mem_cgroup at this point, we have fully - * exclusive access to the page. - */ - - if (memcg != page->mem_cgroup) { - if (memcg) { - uncharge_batch(memcg, pgpgout, nr_anon, nr_file, - nr_kmem, nr_huge, nr_shmem, page); - pgpgout = nr_anon = nr_file = nr_kmem = 0; - nr_huge = nr_shmem = 0; - } - memcg = page->mem_cgroup; - } - - if (!PageKmemcg(page)) { - unsigned int nr_pages = 1; - - if (PageTransHuge(page)) { - nr_pages <<= compound_order(page); - nr_huge += nr_pages; - } - if (PageAnon(page)) - nr_anon += nr_pages; - else { - nr_file += nr_pages; - if (PageSwapBacked(page)) - nr_shmem += nr_pages; - } - pgpgout++; - } else { - nr_kmem += 1 << compound_order(page); - __ClearPageKmemcg(page); - } - - page->mem_cgroup = NULL; + uncharge_page(page, &ug); } while (next != page_list); - if (memcg) - uncharge_batch(memcg, pgpgout, nr_anon, nr_file, - nr_kmem, nr_huge, nr_shmem, page); + if (ug.memcg) + uncharge_batch(&ug); } /** @@ -5651,6 +5664,8 @@ static void uncharge_list(struct list_he */ void mem_cgroup_uncharge(struct page *page) { + struct uncharge_gather ug; + if (mem_cgroup_disabled()) return; @@ -5658,8 +5673,9 @@ void mem_cgroup_uncharge(struct page *pa if (!page->mem_cgroup) return; - INIT_LIST_HEAD(&page->lru); - uncharge_list(&page->lru); + uncharge_gather_clear(&ug); + uncharge_page(page, &ug); + uncharge_batch(&ug); } /** _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
