linux-pikaos-6.12.1/patches/0005-le9uo.patch

From 95eac316f9bb32c4e33e64616876c2ab1dfaf3f4 Mon Sep 17 00:00:00 2001
From: Eric Naim <dnaim@cachyos.org>
Date: Fri, 15 Nov 2024 15:22:08 +0800
Subject: [PATCH] le9uo

Signed-off-by: Eric Naim <dnaim@cachyos.org>
---
 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