On Tue, Feb 08, 2022 at 01:18:55AM -0700, Yu Zhao wrote: <snipped> > diff --git a/mm/Kconfig b/mm/Kconfig > index 3326ee3903f3..e899623d5df0 100644 > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -892,6 +892,50 @@ config ANON_VMA_NAME > area from being merged with adjacent virtual memory areas due to the > difference in their name. > > +# multigenerational LRU { > +config LRU_GEN > + bool "Multigenerational LRU" > + depends on MMU > + # the following options can use up the spare bits in page flags > + depends on !MAXSMP && (64BIT || !SPARSEMEM || SPARSEMEM_VMEMMAP) > + help > + A high performance LRU implementation for memory overcommit. See > + Documentation/admin-guide/mm/multigen_lru.rst and > + Documentation/vm/multigen_lru.rst for details. > + > +config NR_LRU_GENS > + int "Max number of generations" > + depends on LRU_GEN > + range 4 31 > + default 4 > + help > + Do not increase this value unless you plan to use working set > + estimation and proactive reclaim to optimize job scheduling in data > + centers. > + > + This option uses order_base_2(N+1) bits in page flags. > + > +config TIERS_PER_GEN > + int "Number of tiers per generation" > + depends on LRU_GEN > + range 2 4 > + default 4 > + help > + Do not decrease this value unless you run out of spare bits in page > + flags, i.e., you see the "Not enough bits in page flags" build error. > + > + This option uses N-2 bits in page flags. Moved Kconfig to this patch as suggested by: https://lore.kernel.org/linux-mm/Yd6uHYtjGfgqjDpw@xxxxxxxxxxxxxx/ Added two new macros as requested here: https://lore.kernel.org/linux-mm/87czkyzhfe.fsf@xxxxxxxxxxxxx/ <snipped> > diff --git a/mm/vmscan.c b/mm/vmscan.c > index d75a5738d1dc..5f0d92838712 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -1285,9 +1285,11 @@ static int __remove_mapping(struct address_space *mapping, struct page *page, > > if (PageSwapCache(page)) { > swp_entry_t swap = { .val = page_private(page) }; > - mem_cgroup_swapout(page, swap); > + > + /* get a shadow entry before mem_cgroup_swapout() clears folio_memcg() */ > if (reclaimed && !mapping_exiting(mapping)) > shadow = workingset_eviction(page, target_memcg); > + mem_cgroup_swapout(page, swap); > __delete_from_swap_cache(page, swap, shadow); > xa_unlock_irq(&mapping->i_pages); > put_swap_page(page, swap); > @@ -2721,6 +2723,9 @@ static void prepare_scan_count(pg_data_t *pgdat, struct scan_control *sc) > unsigned long file; > struct lruvec *target_lruvec; > > + if (lru_gen_enabled()) > + return; > + > target_lruvec = mem_cgroup_lruvec(sc->target_mem_cgroup, pgdat); > > /* > @@ -3042,15 +3047,47 @@ static bool can_age_anon_pages(struct pglist_data *pgdat, > > #ifdef CONFIG_LRU_GEN > > +enum { > + TYPE_ANON, > + TYPE_FILE, > +}; Added two new macros as requested here: https://lore.kernel.org/linux-mm/87czkyzhfe.fsf@xxxxxxxxxxxxx/ <snipped> > +static void age_lruvec(struct lruvec *lruvec, struct scan_control *sc) > +{ > + bool need_aging; > + long nr_to_scan; > + struct mem_cgroup *memcg = lruvec_memcg(lruvec); > + int swappiness = get_swappiness(memcg); > + DEFINE_MAX_SEQ(lruvec); > + DEFINE_MIN_SEQ(lruvec); > + > + mem_cgroup_calculate_protection(NULL, memcg); > + > + if (mem_cgroup_below_min(memcg)) > + return; Added mem_cgroup_calculate_protection() for readability as requested here: https://lore.kernel.org/linux-mm/Ydf9RXPch5ddg%2FWC@xxxxxxxxxxxxxx/ <snipped>