kernel-5.15/le9pf.diff

diff --git a/Documentation/admin-guide/sysctl/vm.rst b/Documentation/admin-guide/sysctl/vm.rst
index f455fa00c00f..a6146e0fc88a 100644
--- a/Documentation/admin-guide/sysctl/vm.rst
+++ b/Documentation/admin-guide/sysctl/vm.rst
@@ -69,6 +69,8 @@ Currently, these files are in /proc/sys/vm:
 - stat_refresh
 - numa_stat
 - swappiness
+- unevictable_activefile_kbytes_low
+- unevictable_activefile_kbytes_min
 - unprivileged_userfaultfd
 - user_reserve_kbytes
 - vfs_cache_pressure
@@ -881,6 +883,31 @@ privileged users (with SYS_CAP_PTRACE capability).
 The default value is 1.
 
 
+unevictable_activefile_kbytes_low
+=================================
+
+Keep some active file pages still mapped under memory pressure to avoid
+potential disk thrashing that may occur due to evicting running executables
+code. This implements soft eviction throttling, and some file pages can still
+be discarded.
+
+Setting it to 0 effectively disables this feature.
+
+The default value is 512 MiB.
+
+
+unevictable_activefile_kbytes_min
+=================================
+
+Keep all active file pages still mapped under memory pressure to avoid
+potential disk thrashing that may occur due to evicting running executables
+code. This is the hard limit.
+
+Setting it to 0 effectively disables this feature.
+
+The default value is 256 MiB.
+
+
 user_reserve_kbytes
 ===================
 
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index afad085960b8..8bb82cf5d74e 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -111,6 +111,22 @@
 static int sixty = 60;
 #endif
 
+#if defined(CONFIG_UNEVICTABLE_ACTIVEFILE)
+#if CONFIG_UNEVICTABLE_ACTIVEFILE_KBYTES_LOW < 0
+#error "CONFIG_UNEVICTABLE_ACTIVEFILE_KBYTES_LOW should be >= 0"
+#endif
+#if CONFIG_UNEVICTABLE_ACTIVEFILE_KBYTES_MIN < 0
+#error "CONFIG_UNEVICTABLE_ACTIVEFILE_KBYTES_MIN should be >= 0"
+#endif
+#if CONFIG_UNEVICTABLE_ACTIVEFILE_KBYTES_LOW < CONFIG_UNEVICTABLE_ACTIVEFILE_KBYTES_MIN
+#error "CONFIG_UNEVICTABLE_ACTIVEFILE_KBYTES_LOW should be >= CONFIG_UNEVICTABLE_ACTIVEFILE_KBYTES_MIN"
+#endif
+unsigned long sysctl_unevictable_activefile_kbytes_low __read_mostly =
+	CONFIG_UNEVICTABLE_ACTIVEFILE_KBYTES_LOW;
+unsigned long sysctl_unevictable_activefile_kbytes_min __read_mostly =
+	CONFIG_UNEVICTABLE_ACTIVEFILE_KBYTES_MIN;
+#endif
+
 static int __maybe_unused neg_one = -1;
 static int __maybe_unused two = 2;
 static int __maybe_unused four = 4;
@@ -3081,6 +3097,25 @@ static struct ctl_table vm_table[] = {
 		.extra1		= SYSCTL_ZERO,
 		.extra2		= SYSCTL_ONE,
 	},
+#endif
+#if defined(CONFIG_UNEVICTABLE_ACTIVEFILE)
+	{
+		.procname	= "unevictable_activefile_kbytes_low",
+		.data		= &sysctl_unevictable_activefile_kbytes_low,
+		.maxlen		= sizeof(sysctl_unevictable_activefile_kbytes_low),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_minmax,
+		.extra1		= &sysctl_unevictable_activefile_kbytes_min,
+	},
+	{
+		.procname	= "unevictable_activefile_kbytes_min",
+		.data		= &sysctl_unevictable_activefile_kbytes_min,
+		.maxlen		= sizeof(sysctl_unevictable_activefile_kbytes_min),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_minmax,
+		.extra1		= &zero_ul,
+		.extra2		= &sysctl_unevictable_activefile_kbytes_low,
+	},
 #endif
 	{
 		.procname	= "user_reserve_kbytes",
diff --git a/mm/Kconfig b/mm/Kconfig
index 390165ffbb0f..1e1fb8ad434a 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -63,6 +63,41 @@ config SPARSEMEM_MANUAL
 
 endchoice
 
+config UNEVICTABLE_ACTIVEFILE
+	bool "Keep some active file pages under memory pressure"
+	depends on SYSCTL
+	def_bool y
+	help
+	  Keep some active file pages still mapped under memory pressure to avoid
+	  potential disk thrashing that may occur due to evicting running executables
+	  code.
+
+	  The UNEVICTABLE_ACTIVEFILE_KBYTES_LOW value defines a threshold to activate
+	  file pages eviction throttling. The vm.unevictable_activefile_kbytes_low
+	  sysctl knob is used to change the amount in the runtime (setting it to 0
+	  effectively disables this feature).
+
+	  Recommended value: 524288 for typical desktop workload.
+
+	  The UNEVICTABLE_ACTIVEFILE_KBYTES_MIN value sets the amount of pages to keep
+	  as a hard limit. The vm.unevictable_activefile_kbytes_min sysctl knob is used
+	  to change the amount in the runtime (setting it to 0 effectively disables
+	  this feature).
+
+	  Recommended value: 262144 for typical desktop workload.
+
+	  See also: Documentation/admin-guide/sysctl/vm.rst
+
+config UNEVICTABLE_ACTIVEFILE_KBYTES_LOW
+	int "Default value for vm.unevictable_activefile_kbytes_low"
+	depends on UNEVICTABLE_ACTIVEFILE
+	default "524288"
+
+config UNEVICTABLE_ACTIVEFILE_KBYTES_MIN
+	int "Default value for vm.unevictable_activefile_kbytes_min"
+	depends on UNEVICTABLE_ACTIVEFILE
+	default "262144"
+
 config DISCONTIGMEM
 	def_bool y
 	depends on (!SELECT_MEMORY_MODEL && ARCH_DISCONTIGMEM_ENABLE) || DISCONTIGMEM_MANUAL
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 7b4e31eac2cf..93760769d676 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -166,6 +166,11 @@ struct scan_control {
 #define prefetchw_prev_lru_page(_page, _base, _field) do { } while (0)
 #endif
 
+#if defined(CONFIG_UNEVICTABLE_ACTIVEFILE)
+extern unsigned long sysctl_unevictable_activefile_kbytes_low;
+extern unsigned long sysctl_unevictable_activefile_kbytes_min;
+#endif
+
 /*
  * From 0 .. 200.  Higher means more swappy.
  */
@@ -2225,6 +2230,10 @@ enum scan_balance {
 	SCAN_FILE,
 };
 
+#if defined(CONFIG_UNEVICTABLE_ACTIVEFILE)
+#define K(x) ((x) << (PAGE_SHIFT - 10))
+#endif
+
 /*
  * Determine how aggressively the anon and file LRU lists should be
  * scanned.  The relative value of each set of LRU lists is determined
@@ -2418,6 +2427,19 @@ static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc,
 			BUG();
 		}
 
+#if defined(CONFIG_UNEVICTABLE_ACTIVEFILE)
+		if (lru == LRU_ACTIVE_FILE) {
+			unsigned long activefile_kbytes_now = K(global_node_page_state(NR_ACTIVE_FILE));
+			unsigned long low_scan_granularity = SWAP_CLUSTER_MAX >> sc->priority;
+
+			if (activefile_kbytes_now < sysctl_unevictable_activefile_kbytes_low &&
+				activefile_kbytes_now > sysctl_unevictable_activefile_kbytes_min &&
+				scan > low_scan_granularity)
+				scan = low_scan_granularity;
+			else if (activefile_kbytes_now <= sysctl_unevictable_activefile_kbytes_min)
+				scan = 0;
+		}
+#endif
 		nr[lru] = scan;
 	}
 }