From 95eac316f9bb32c4e33e64616876c2ab1dfaf3f4 Mon Sep 17 00:00:00 2001 From: Eric Naim Date: Fri, 15 Nov 2024 15:22:08 +0800 Subject: [PATCH] le9uo Signed-off-by: Eric Naim --- Documentation/admin-guide/sysctl/vm.rst | 72 ++++++++++++ include/linux/mm.h | 8 ++ kernel/sysctl.c | 34 ++++++ mm/Kconfig | 63 +++++++++++ mm/mm_init.c | 1 + mm/vmscan.c | 143 +++++++++++++++++++++++- 6 files changed, 317 insertions(+), 4 deletions(-) diff --git a/Documentation/admin-guide/sysctl/vm.rst b/Documentation/admin-guide/sysctl/vm.rst index f48eaa98d22d..fc777c14cff6 100644 --- a/Documentation/admin-guide/sysctl/vm.rst +++ b/Documentation/admin-guide/sysctl/vm.rst @@ -25,6 +25,9 @@ files can be found in mm/swap.c. Currently, these files are in /proc/sys/vm: - admin_reserve_kbytes +- anon_min_ratio +- clean_low_ratio +- clean_min_ratio - compact_memory - compaction_proactiveness - compact_unevictable_allowed @@ -108,6 +111,67 @@ On x86_64 this is about 128MB. Changing this takes effect whenever an application requests memory. +anon_min_ratio +============== + +This knob provides *hard* protection of anonymous pages. The anonymous pages +on the current node won't be reclaimed under any conditions when their amount +is below vm.anon_min_ratio. + +This knob may be used to prevent excessive swap thrashing when anonymous +memory is low (for example, when memory is going to be overfilled by +compressed data of zram module). + +Setting this value too high (close to 100) can result in inability to +swap and can lead to early OOM under memory pressure. + +The unit of measurement is the percentage of the total memory of the node. + +The default value is 15. + + +clean_low_ratio +================ + +This knob provides *best-effort* protection of clean file pages. The file pages +on the current node won't be reclaimed under memory pressure when the amount of +clean file pages is below vm.clean_low_ratio *unless* we threaten to OOM. + +Protection of clean file pages using this knob may be used when swapping is +still possible to + - prevent disk I/O thrashing under memory pressure; + - improve performance in disk cache-bound tasks under memory pressure. + +Setting it to a high value may result in a early eviction of anonymous pages +into the swap space by attempting to hold the protected amount of clean file +pages in memory. + +The unit of measurement is the percentage of the total memory of the node. + +The default value is 0. + + +clean_min_ratio +================ + +This knob provides *hard* protection of clean file pages. The file pages on the +current node won't be reclaimed under memory pressure when the amount of clean +file pages is below vm.clean_min_ratio. + +Hard protection of clean file pages using this knob may be used to + - prevent disk I/O thrashing under memory pressure even with no free swap space; + - improve performance in disk cache-bound tasks under memory pressure; + - avoid high latency and prevent livelock in near-OOM conditions. + +Setting it to a high value may result in a early out-of-memory condition due to +the inability to reclaim the protected amount of clean file pages when other +types of pages cannot be reclaimed. + +The unit of measurement is the percentage of the total memory of the node. + +The default value is 15. + + compact_memory ============== @@ -964,6 +1028,14 @@ be 133 (x + 2x = 200, 2x = 133.33). At 0, the kernel will not initiate swap until the amount of free and file-backed pages is less than the high watermark in a zone. +This knob has no effect if the amount of clean file pages on the current +node is below vm.clean_low_ratio or vm.clean_min_ratio. In this case, +only anonymous pages can be reclaimed. + +If the number of anonymous pages on the current node is below +vm.anon_min_ratio, then only file pages can be reclaimed with +any vm.swappiness value. + unprivileged_userfaultfd ======================== diff --git a/include/linux/mm.h b/include/linux/mm.h index 61fff5d34ed5..18dc2544700b 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -205,6 +205,14 @@ static inline void __mm_zero_struct_page(struct page *page) extern int sysctl_max_map_count; +extern bool sysctl_workingset_protection; +extern u8 sysctl_anon_min_ratio; +extern u8 sysctl_clean_low_ratio; +extern u8 sysctl_clean_min_ratio; +int vm_workingset_protection_update_handler( + const struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, loff_t *ppos); + extern unsigned long sysctl_user_reserve_kbytes; extern unsigned long sysctl_admin_reserve_kbytes; diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 676e89dc38c3..4a62ae02a2c0 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -2210,6 +2210,40 @@ static struct ctl_table vm_table[] = { .extra1 = SYSCTL_ZERO, }, #endif + { + .procname = "workingset_protection", + .data = &sysctl_workingset_protection, + .maxlen = sizeof(bool), + .mode = 0644, + .proc_handler = &proc_dobool, + }, + { + .procname = "anon_min_ratio", + .data = &sysctl_anon_min_ratio, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = &vm_workingset_protection_update_handler, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE_HUNDRED, + }, + { + .procname = "clean_low_ratio", + .data = &sysctl_clean_low_ratio, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = &vm_workingset_protection_update_handler, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE_HUNDRED, + }, + { + .procname = "clean_min_ratio", + .data = &sysctl_clean_min_ratio, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = &vm_workingset_protection_update_handler, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE_HUNDRED, + }, { .procname = "user_reserve_kbytes", .data = &sysctl_user_reserve_kbytes, diff --git a/mm/Kconfig b/mm/Kconfig index 6bfea371341e..87cb63f7ca57 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -499,6 +499,69 @@ config ARCH_WANT_OPTIMIZE_DAX_VMEMMAP config ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP bool +config ANON_MIN_RATIO + int "Default value for vm.anon_min_ratio" + depends on SYSCTL + range 0 100 + default 15 + help + This option sets the default value for vm.anon_min_ratio sysctl knob. + + The vm.anon_min_ratio sysctl knob provides *hard* protection of + anonymous pages. The anonymous pages on the current node won't be + reclaimed under any conditions when their amount is below + vm.anon_min_ratio. This knob may be used to prevent excessive swap + thrashing when anonymous memory is low (for example, when memory is + going to be overfilled by compressed data of zram module). + + Setting this value too high (close to MemTotal) can result in + inability to swap and can lead to early OOM under memory pressure. + +config CLEAN_LOW_RATIO + int "Default value for vm.clean_low_ratio" + depends on SYSCTL + range 0 100 + default 0 + help + This option sets the default value for vm.clean_low_ratio sysctl knob. + + The vm.clean_low_ratio sysctl knob provides *best-effort* + protection of clean file pages. The file pages on the current node + won't be reclaimed under memory pressure when the amount of clean file + pages is below vm.clean_low_ratio *unless* we threaten to OOM. + Protection of clean file pages using this knob may be used when + swapping is still possible to + - prevent disk I/O thrashing under memory pressure; + - improve performance in disk cache-bound tasks under memory + pressure. + + Setting it to a high value may result in a early eviction of anonymous + pages into the swap space by attempting to hold the protected amount + of clean file pages in memory. + +config CLEAN_MIN_RATIO + int "Default value for vm.clean_min_ratio" + depends on SYSCTL + range 0 100 + default 15 + help + This option sets the default value for vm.clean_min_ratio sysctl knob. + + The vm.clean_min_ratio sysctl knob provides *hard* protection of + clean file pages. The file pages on the current node won't be + reclaimed under memory pressure when the amount of clean file pages is + below vm.clean_min_ratio. Hard protection of clean file pages using + this knob may be used to + - prevent disk I/O thrashing under memory pressure even with no free + swap space; + - improve performance in disk cache-bound tasks under memory + pressure; + - avoid high latency and prevent livelock in near-OOM conditions. + + Setting it to a high value may result in a early out-of-memory condition + due to the inability to reclaim the protected amount of clean file pages + when other types of pages cannot be reclaimed. + config HAVE_MEMBLOCK_PHYS_MAP bool diff --git a/mm/mm_init.c b/mm/mm_init.c index 4ba5607aaf19..0a83f8973ddf 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -2628,6 +2628,7 @@ static void __init mem_init_print_info(void) , K(totalhigh_pages()) #endif ); + printk(KERN_INFO "le9 Unofficial (le9uo) working set protection 1.7 by Masahito Suzuki (forked from hakavlad's original le9 patch)"); } /* diff --git a/mm/vmscan.c b/mm/vmscan.c index 99568ccfb0fd..af10b7d3407a 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -148,6 +148,15 @@ struct scan_control { /* The file folios on the current node are dangerously low */ unsigned int file_is_tiny:1; + /* The anonymous pages on the current node are below vm.anon_min_ratio */ + unsigned int anon_below_min:1; + + /* The clean file pages on the current node are below vm.clean_low_ratio */ + unsigned int clean_below_low:1; + + /* The clean file pages on the current node are below vm.clean_min_ratio */ + unsigned int clean_below_min:1; + /* Always discard instead of demoting to lower tier memory */ unsigned int no_demotion:1; @@ -197,6 +206,15 @@ struct scan_control { #define prefetchw_prev_lru_folio(_folio, _base, _field) do { } while (0) #endif +bool sysctl_workingset_protection __read_mostly = true; +u8 sysctl_anon_min_ratio __read_mostly = CONFIG_ANON_MIN_RATIO; +u8 sysctl_clean_low_ratio __read_mostly = CONFIG_CLEAN_LOW_RATIO; +u8 sysctl_clean_min_ratio __read_mostly = CONFIG_CLEAN_MIN_RATIO; +static u64 sysctl_anon_min_ratio_kb __read_mostly = 0; +static u64 sysctl_clean_low_ratio_kb __read_mostly = 0; +static u64 sysctl_clean_min_ratio_kb __read_mostly = 0; +static u64 workingset_protection_prev_totalram __read_mostly = 0; + /* * From 0 .. MAX_SWAPPINESS. Higher means more swappy. */ @@ -1094,6 +1112,10 @@ static unsigned int shrink_folio_list(struct list_head *folio_list, folio_mapped(folio) && folio_test_referenced(folio)) goto keep_locked; + if (folio_is_file_lru(folio) ? sc->clean_below_min : + (sc->anon_below_min && !sc->clean_below_min)) + goto keep_locked; + /* * The number of dirty pages determines if a node is marked * reclaim_congested. kswapd will stall and start writing @@ -2419,6 +2441,15 @@ static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc, goto out; } + /* + * Force-scan anon if clean file pages is under vm.clean_low_ratio + * or vm.clean_min_ratio. + */ + if (sc->clean_below_low || sc->clean_below_min) { + scan_balance = SCAN_ANON; + goto out; + } + /* * If there is enough inactive page cache, we do not reclaim * anything from the anonymous working right now. @@ -2563,6 +2594,14 @@ static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc, BUG(); } + /* + * Hard protection of the working set. + * Don't reclaim anon/file pages when the amount is + * below the watermark of the same type. + */ + if (file ? sc->clean_below_min : sc->anon_below_min) + scan = 0; + nr[lru] = scan; } } @@ -3996,11 +4035,7 @@ static bool lruvec_is_reclaimable(struct lruvec *lruvec, struct scan_control *sc } /* to protect the working set of the last N jiffies */ -#ifdef CONFIG_CACHY -static unsigned long lru_gen_min_ttl __read_mostly = 1000; -#else static unsigned long lru_gen_min_ttl __read_mostly; -#endif static void lru_gen_age_node(struct pglist_data *pgdat, struct scan_control *sc) { @@ -4038,6 +4073,96 @@ static void lru_gen_age_node(struct pglist_data *pgdat, struct scan_control *sc) } } +int vm_workingset_protection_update_handler(const struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, loff_t *ppos) +{ + int ret = proc_dou8vec_minmax(table, write, buffer, lenp, ppos); + if (ret || !write) + return ret; + + workingset_protection_prev_totalram = 0; + + return 0; +} + +static void prepare_workingset_protection(pg_data_t *pgdat, struct scan_control *sc) +{ + unsigned long node_mem_total; + struct sysinfo i; + + if (!(sysctl_workingset_protection)) { + sc->anon_below_min = 0; + sc->clean_below_low = 0; + sc->clean_below_min = 0; + return; + } + + if (likely(sysctl_anon_min_ratio || + sysctl_clean_low_ratio || + sysctl_clean_min_ratio)) { +#ifdef CONFIG_NUMA + si_meminfo_node(&i, pgdat->node_id); +#else //CONFIG_NUMA + si_meminfo(&i); +#endif //CONFIG_NUMA + node_mem_total = i.totalram; + + if (unlikely(workingset_protection_prev_totalram != node_mem_total)) { + sysctl_anon_min_ratio_kb = + node_mem_total * sysctl_anon_min_ratio / 100; + sysctl_clean_low_ratio_kb = + node_mem_total * sysctl_clean_low_ratio / 100; + sysctl_clean_min_ratio_kb = + node_mem_total * sysctl_clean_min_ratio / 100; + workingset_protection_prev_totalram = node_mem_total; + } + } + + /* + * Check the number of anonymous pages to protect them from + * reclaiming if their amount is below the specified. + */ + if (sysctl_anon_min_ratio) { + unsigned long reclaimable_anon; + + reclaimable_anon = + node_page_state(pgdat, NR_ACTIVE_ANON) + + node_page_state(pgdat, NR_INACTIVE_ANON) + + node_page_state(pgdat, NR_ISOLATED_ANON); + + sc->anon_below_min = reclaimable_anon < sysctl_anon_min_ratio_kb; + } else + sc->anon_below_min = 0; + + /* + * Check the number of clean file pages to protect them from + * reclaiming if their amount is below the specified. + */ + if (sysctl_clean_low_ratio || sysctl_clean_min_ratio) { + unsigned long reclaimable_file, dirty, clean; + + reclaimable_file = + node_page_state(pgdat, NR_ACTIVE_FILE) + + node_page_state(pgdat, NR_INACTIVE_FILE) + + node_page_state(pgdat, NR_ISOLATED_FILE); + dirty = node_page_state(pgdat, NR_FILE_DIRTY); + /* + * node_page_state() sum can go out of sync since + * all the values are not read at once. + */ + if (likely(reclaimable_file > dirty)) + clean = reclaimable_file - dirty; + else + clean = 0; + + sc->clean_below_low = clean < sysctl_clean_low_ratio_kb; + sc->clean_below_min = clean < sysctl_clean_min_ratio_kb; + } else { + sc->clean_below_low = 0; + sc->clean_below_min = 0; + } +} + /****************************************************************************** * rmap/PT walk feedback ******************************************************************************/ @@ -4536,6 +4661,12 @@ static int isolate_folios(struct lruvec *lruvec, struct scan_control *sc, int sw */ if (!swappiness) type = LRU_GEN_FILE; + else if (sc->clean_below_min) + type = LRU_GEN_ANON; + else if (sc->anon_below_min) + type = LRU_GEN_FILE; + else if (sc->clean_below_low) + type = LRU_GEN_ANON; else if (min_seq[LRU_GEN_ANON] < min_seq[LRU_GEN_FILE]) type = LRU_GEN_ANON; else if (swappiness == 1) @@ -4815,6 +4946,8 @@ static int shrink_one(struct lruvec *lruvec, struct scan_control *sc) struct mem_cgroup *memcg = lruvec_memcg(lruvec); struct pglist_data *pgdat = lruvec_pgdat(lruvec); + prepare_workingset_protection(pgdat, sc); + /* lru_gen_age_node() called mem_cgroup_calculate_protection() */ if (mem_cgroup_below_min(NULL, memcg)) return MEMCG_LRU_YOUNG; @@ -5962,6 +6095,8 @@ static void shrink_node(pg_data_t *pgdat, struct scan_control *sc) prepare_scan_control(pgdat, sc); + prepare_workingset_protection(pgdat, sc); + shrink_node_memcgs(pgdat, sc); flush_reclaim_state(sc); -- 2.47.0