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authorJoel Fernandes <joelagnelf@nvidia.com>2026-07-18 13:15:36 -0400
committerPaul E. McKenney <paulmck@kernel.org>2026-07-23 10:39:57 -0700
commit34ff636f322c6d5e4f0a52338fa63a7dff09a495 (patch)
tree7629759c1ec7148b95bc8ab3080df20a5ecd2273 /samples/damon
downloadlinux-stable-34ff636f322c6d5e4f0a52338fa63a7dff09a495.tar.gz
linux-stable-34ff636f322c6d5e4f0a52338fa63a7dff09a495.zip
scftorture: Count single_rpc offline failures in statistics outputgrafted
scf_torture_stats_print() aggregates each invoker thread's counters into a local scf_statistics structure before printing, but the n_single_rpc_ofl field is missing from the aggregation loop. As a result, the "single_rpc_ofl" value printed in the statistics line is always zero, even when smp_call_function_single() invocations for the RPC test have failed due to offline CPUs and been counted by the invoker threads. Add the missing accumulation so that the printed value reflects the actual counts. Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'samples/damon')
-rw-r--r--samples/damon/Kconfig43
-rw-r--r--samples/damon/Makefile5
-rw-r--r--samples/damon/mtier.c245
-rw-r--r--samples/damon/prcl.c169
-rw-r--r--samples/damon/wsse.c149
5 files changed, 611 insertions, 0 deletions
diff --git a/samples/damon/Kconfig b/samples/damon/Kconfig
new file mode 100644
index 000000000..cbf96fd8a
--- /dev/null
+++ b/samples/damon/Kconfig
@@ -0,0 +1,43 @@
+# SPDX-License-Identifier: GPL-2.0
+
+menu "DAMON Samples"
+
+config SAMPLE_DAMON_WSSE
+ bool "DAMON sample module for working set size estimation"
+ depends on DAMON && DAMON_VADDR
+ help
+ This builds DAMON sample module for working set size estimation.
+
+ The module receives a pid, monitor access to the virtual address
+ space of the process, estimate working set size of the process, and
+ repeatedly prints the size on the kernel log.
+
+ If unsure, say N.
+
+config SAMPLE_DAMON_PRCL
+ bool "DAMON sample module for access-aware proactive reclamation"
+ depends on DAMON && DAMON_VADDR
+ help
+ This builds DAMON sample module for access-aware proactive
+ reclamation.
+
+ The module receives a pid, monitor access to the virtual address
+ space of the process, find memory regions that not accessed, and
+ proactively reclaim the regions.
+
+ If unsure, say N.
+
+config SAMPLE_DAMON_MTIER
+ bool "DAMON sample module for memory tiering"
+ depends on DAMON && DAMON_PADDR
+ help
+ Thps builds DAMON sample module for memory tierign.
+
+ The module assumes the system is constructed with two NUMA nodes,
+ which seems as local and remote nodes to all CPUs. For example,
+ node0 is for DDR5 DRAMs connected via DIMM, while node1 is for DDR4
+ DRAMs connected via CXL.
+
+ If unsure, say N.
+
+endmenu
diff --git a/samples/damon/Makefile b/samples/damon/Makefile
new file mode 100644
index 000000000..72f68cbf4
--- /dev/null
+++ b/samples/damon/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_SAMPLE_DAMON_WSSE) += wsse.o
+obj-$(CONFIG_SAMPLE_DAMON_PRCL) += prcl.o
+obj-$(CONFIG_SAMPLE_DAMON_MTIER) += mtier.o
diff --git a/samples/damon/mtier.c b/samples/damon/mtier.c
new file mode 100644
index 000000000..3785b0c7f
--- /dev/null
+++ b/samples/damon/mtier.c
@@ -0,0 +1,245 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * memory tiering: migrate cold pages in node 0 and hot pages in node 1 to node
+ * 1 and node 0, respectively. Adjust the hotness/coldness threshold aiming
+ * resulting 99.6 % node 0 utilization ratio.
+ */
+
+#define pr_fmt(fmt) "damon_sample_mtier: " fmt
+
+#include <linux/damon.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#ifdef MODULE_PARAM_PREFIX
+#undef MODULE_PARAM_PREFIX
+#endif
+#define MODULE_PARAM_PREFIX "damon_sample_mtier."
+
+static unsigned long node0_start_addr __read_mostly;
+module_param(node0_start_addr, ulong, 0600);
+
+static unsigned long node0_end_addr __read_mostly;
+module_param(node0_end_addr, ulong, 0600);
+
+static unsigned long node1_start_addr __read_mostly;
+module_param(node1_start_addr, ulong, 0600);
+
+static unsigned long node1_end_addr __read_mostly;
+module_param(node1_end_addr, ulong, 0600);
+
+static unsigned long node0_mem_used_bp __read_mostly = 9970;
+module_param(node0_mem_used_bp, ulong, 0600);
+
+static unsigned long node0_mem_free_bp __read_mostly = 50;
+module_param(node0_mem_free_bp, ulong, 0600);
+
+static int damon_sample_mtier_enable_store(
+ const char *val, const struct kernel_param *kp);
+
+static const struct kernel_param_ops enabled_param_ops = {
+ .set = damon_sample_mtier_enable_store,
+ .get = param_get_bool,
+};
+
+static bool enabled __read_mostly;
+module_param_cb(enabled, &enabled_param_ops, &enabled, 0600);
+MODULE_PARM_DESC(enabled, "Enable or disable DAMON_SAMPLE_MTIER");
+
+static bool detect_node_addresses __read_mostly;
+module_param(detect_node_addresses, bool, 0600);
+
+static struct damon_ctx *ctxs[2];
+
+struct region_range {
+ phys_addr_t start;
+ phys_addr_t end;
+};
+
+static int nid_to_phys(int target_node, struct region_range *range)
+{
+ if (!node_online(target_node)) {
+ pr_err("NUMA node %d is not online\n", target_node);
+ return -EINVAL;
+ }
+
+ range->start = PFN_PHYS(node_start_pfn(target_node));
+ range->end = PFN_PHYS(node_end_pfn(target_node));
+
+ return 0;
+}
+
+static struct damon_ctx *damon_sample_mtier_build_ctx(bool promote)
+{
+ struct damon_ctx *ctx;
+ struct damon_attrs attrs;
+ struct damon_target *target;
+ struct damos *scheme;
+ struct damos_quota_goal *quota_goal;
+ struct damos_filter *filter;
+ struct region_range addr;
+ struct damon_addr_range range;
+ int ret;
+
+ ctx = damon_new_ctx();
+ if (!ctx)
+ return NULL;
+ attrs = (struct damon_attrs) {
+ .sample_interval = 5 * USEC_PER_MSEC,
+ .aggr_interval = 100 * USEC_PER_MSEC,
+ .ops_update_interval = 60 * USEC_PER_MSEC * MSEC_PER_SEC,
+ .min_nr_regions = 10,
+ .max_nr_regions = 1000,
+ };
+
+ /*
+ * auto-tune sampling and aggregation interval aiming 4% DAMON-observed
+ * accesses ratio, keeping sampling interval in [5ms, 10s] range.
+ */
+ attrs.intervals_goal = (struct damon_intervals_goal) {
+ .access_bp = 400, .aggrs = 3,
+ .min_sample_us = 5000, .max_sample_us = 10000000,
+ };
+ if (damon_set_attrs(ctx, &attrs))
+ goto free_out;
+ if (damon_select_ops(ctx, DAMON_OPS_PADDR))
+ goto free_out;
+
+ target = damon_new_target();
+ if (!target)
+ goto free_out;
+ damon_add_target(ctx, target);
+
+ if (detect_node_addresses) {
+ ret = promote ? nid_to_phys(1, &addr) : nid_to_phys(0, &addr);
+ if (ret)
+ goto free_out;
+ } else {
+ addr.start = promote ? node1_start_addr : node0_start_addr;
+ addr.end = promote ? node1_end_addr : node0_end_addr;
+ }
+
+ if (addr.start >= addr.end)
+ goto free_out;
+
+ range.start = addr.start;
+ range.end = addr.end;
+
+ ret = damon_set_regions(target, &range, 1, DAMON_MIN_REGION_SZ);
+ if (ret)
+ goto free_out;
+
+ scheme = damon_new_scheme(
+ /* access pattern */
+ &(struct damos_access_pattern) {
+ .min_sz_region = PAGE_SIZE,
+ .max_sz_region = ULONG_MAX,
+ .min_nr_accesses = promote ? 1 : 0,
+ .max_nr_accesses = promote ? UINT_MAX : 0,
+ .min_age_region = 0,
+ .max_age_region = UINT_MAX},
+ /* action */
+ promote ? DAMOS_MIGRATE_HOT : DAMOS_MIGRATE_COLD,
+ 1000000, /* apply interval (1s) */
+ &(struct damos_quota){
+ /* 200 MiB per sec by most */
+ .reset_interval = 1000,
+ .sz = 200 * 1024 * 1024,
+ /* ignore size of region when prioritizing */
+ .weight_sz = 0,
+ .weight_nr_accesses = 100,
+ .weight_age = 100,
+ },
+ &(struct damos_watermarks){},
+ promote ? 0 : 1); /* migrate target node id */
+ if (!scheme)
+ goto free_out;
+ damon_set_schemes(ctx, &scheme, 1);
+ quota_goal = damos_new_quota_goal(
+ promote ? DAMOS_QUOTA_NODE_MEM_USED_BP :
+ DAMOS_QUOTA_NODE_MEM_FREE_BP,
+ promote ? node0_mem_used_bp : node0_mem_free_bp);
+ if (!quota_goal)
+ goto free_out;
+ quota_goal->nid = 0;
+ damos_add_quota_goal(&scheme->quota, quota_goal);
+ filter = damos_new_filter(DAMOS_FILTER_TYPE_YOUNG, true, promote);
+ if (!filter)
+ goto free_out;
+ damos_add_filter(scheme, filter);
+ return ctx;
+free_out:
+ damon_destroy_ctx(ctx);
+ return NULL;
+}
+
+static int damon_sample_mtier_start(void)
+{
+ struct damon_ctx *ctx;
+
+ ctx = damon_sample_mtier_build_ctx(true);
+ if (!ctx)
+ return -ENOMEM;
+ ctxs[0] = ctx;
+ ctx = damon_sample_mtier_build_ctx(false);
+ if (!ctx) {
+ damon_destroy_ctx(ctxs[0]);
+ return -ENOMEM;
+ }
+ ctxs[1] = ctx;
+ return damon_start(ctxs, 2, true);
+}
+
+static void damon_sample_mtier_stop(void)
+{
+ damon_stop(ctxs, 2);
+ damon_destroy_ctx(ctxs[0]);
+ damon_destroy_ctx(ctxs[1]);
+}
+
+static int damon_sample_mtier_enable_store(
+ const char *val, const struct kernel_param *kp)
+{
+ bool is_enabled = enabled;
+ int err;
+
+ err = kstrtobool(val, &enabled);
+ if (err)
+ return err;
+
+ if (enabled == is_enabled)
+ return 0;
+
+ if (!damon_initialized())
+ return 0;
+
+ if (enabled) {
+ err = damon_sample_mtier_start();
+ if (err)
+ enabled = false;
+ return err;
+ }
+ damon_sample_mtier_stop();
+ return 0;
+}
+
+static int __init damon_sample_mtier_init(void)
+{
+ int err = 0;
+
+ if (!damon_initialized()) {
+ if (enabled)
+ enabled = false;
+ return -ENOMEM;
+ }
+
+ if (enabled) {
+ err = damon_sample_mtier_start();
+ if (err)
+ enabled = false;
+ }
+ return 0;
+}
+
+module_init(damon_sample_mtier_init);
diff --git a/samples/damon/prcl.c b/samples/damon/prcl.c
new file mode 100644
index 000000000..b7c50f265
--- /dev/null
+++ b/samples/damon/prcl.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * proactive reclamation: monitor access pattern of a given process, find
+ * regions that seems not accessed, and proactively page out the regions.
+ */
+
+#define pr_fmt(fmt) "damon_sample_prcl: " fmt
+
+#include <linux/damon.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#ifdef MODULE_PARAM_PREFIX
+#undef MODULE_PARAM_PREFIX
+#endif
+#define MODULE_PARAM_PREFIX "damon_sample_prcl."
+
+static int target_pid __read_mostly;
+module_param(target_pid, int, 0600);
+
+static int damon_sample_prcl_enable_store(
+ const char *val, const struct kernel_param *kp);
+
+static const struct kernel_param_ops enabled_param_ops = {
+ .set = damon_sample_prcl_enable_store,
+ .get = param_get_bool,
+};
+
+static bool enabled __read_mostly;
+module_param_cb(enabled, &enabled_param_ops, &enabled, 0600);
+MODULE_PARM_DESC(enabled, "Enable or disable DAMON_SAMPLE_PRCL");
+
+static struct damon_ctx *ctx;
+static struct pid *target_pidp;
+
+static int damon_sample_prcl_repeat_call_fn(void *data)
+{
+ struct damon_ctx *c = data;
+ struct damon_target *t;
+
+ damon_for_each_target(t, c) {
+ struct damon_region *r;
+ unsigned long wss = 0;
+
+ damon_for_each_region(r, t) {
+ if (r->nr_accesses > 0)
+ wss += r->ar.end - r->ar.start;
+ }
+ pr_info("wss: %lu\n", wss);
+ }
+ return 0;
+}
+
+static struct damon_call_control repeat_call_control = {
+ .fn = damon_sample_prcl_repeat_call_fn,
+ .repeat = true,
+};
+
+static int damon_sample_prcl_start(void)
+{
+ struct damon_target *target;
+ struct damos *scheme;
+ int err;
+
+ pr_info("start\n");
+
+ ctx = damon_new_ctx();
+ if (!ctx)
+ return -ENOMEM;
+ if (damon_select_ops(ctx, DAMON_OPS_VADDR)) {
+ damon_destroy_ctx(ctx);
+ return -EINVAL;
+ }
+
+ target = damon_new_target();
+ if (!target) {
+ damon_destroy_ctx(ctx);
+ return -ENOMEM;
+ }
+ damon_add_target(ctx, target);
+ target_pidp = find_get_pid(target_pid);
+ if (!target_pidp) {
+ damon_destroy_ctx(ctx);
+ return -EINVAL;
+ }
+ target->pid = target_pidp;
+
+ scheme = damon_new_scheme(
+ &(struct damos_access_pattern) {
+ .min_sz_region = PAGE_SIZE,
+ .max_sz_region = ULONG_MAX,
+ .min_nr_accesses = 0,
+ .max_nr_accesses = 0,
+ .min_age_region = 50,
+ .max_age_region = UINT_MAX},
+ DAMOS_PAGEOUT,
+ 0,
+ &(struct damos_quota){},
+ &(struct damos_watermarks){},
+ NUMA_NO_NODE);
+ if (!scheme) {
+ damon_destroy_ctx(ctx);
+ return -ENOMEM;
+ }
+ damon_set_schemes(ctx, &scheme, 1);
+
+ err = damon_start(&ctx, 1, true);
+ if (err)
+ return err;
+
+ repeat_call_control.data = ctx;
+ return damon_call(ctx, &repeat_call_control);
+}
+
+static void damon_sample_prcl_stop(void)
+{
+ pr_info("stop\n");
+ if (ctx) {
+ damon_stop(&ctx, 1);
+ damon_destroy_ctx(ctx);
+ }
+}
+
+static int damon_sample_prcl_enable_store(
+ const char *val, const struct kernel_param *kp)
+{
+ bool is_enabled = enabled;
+ int err;
+
+ err = kstrtobool(val, &enabled);
+ if (err)
+ return err;
+
+ if (enabled == is_enabled)
+ return 0;
+
+ if (!damon_initialized())
+ return 0;
+
+ if (enabled) {
+ err = damon_sample_prcl_start();
+ if (err)
+ enabled = false;
+ return err;
+ }
+ damon_sample_prcl_stop();
+ return 0;
+}
+
+static int __init damon_sample_prcl_init(void)
+{
+ int err = 0;
+
+ if (!damon_initialized()) {
+ if (enabled)
+ enabled = false;
+ return -ENOMEM;
+ }
+
+ if (enabled) {
+ err = damon_sample_prcl_start();
+ if (err)
+ enabled = false;
+ }
+ return 0;
+}
+
+module_init(damon_sample_prcl_init);
diff --git a/samples/damon/wsse.c b/samples/damon/wsse.c
new file mode 100644
index 000000000..799ad4443
--- /dev/null
+++ b/samples/damon/wsse.c
@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * working set size estimation: monitor access pattern of given process and
+ * print estimated working set size (total size of regions that showing some
+ * access).
+ */
+
+#define pr_fmt(fmt) "damon_sample_wsse: " fmt
+
+#include <linux/damon.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#ifdef MODULE_PARAM_PREFIX
+#undef MODULE_PARAM_PREFIX
+#endif
+#define MODULE_PARAM_PREFIX "damon_sample_wsse."
+
+static int target_pid __read_mostly;
+module_param(target_pid, int, 0600);
+
+static int damon_sample_wsse_enable_store(
+ const char *val, const struct kernel_param *kp);
+
+static const struct kernel_param_ops enabled_param_ops = {
+ .set = damon_sample_wsse_enable_store,
+ .get = param_get_bool,
+};
+
+static bool enabled __read_mostly;
+module_param_cb(enabled, &enabled_param_ops, &enabled, 0600);
+MODULE_PARM_DESC(enabled, "Enable or disable DAMON_SAMPLE_WSSE");
+
+static struct damon_ctx *ctx;
+static struct pid *target_pidp;
+
+static int damon_sample_wsse_repeat_call_fn(void *data)
+{
+ struct damon_ctx *c = data;
+ struct damon_target *t;
+
+ damon_for_each_target(t, c) {
+ struct damon_region *r;
+ unsigned long wss = 0;
+
+ damon_for_each_region(r, t) {
+ if (r->nr_accesses > 0)
+ wss += r->ar.end - r->ar.start;
+ }
+ pr_info("wss: %lu\n", wss);
+ }
+ return 0;
+}
+
+static struct damon_call_control repeat_call_control = {
+ .fn = damon_sample_wsse_repeat_call_fn,
+ .repeat = true,
+};
+
+static int damon_sample_wsse_start(void)
+{
+ struct damon_target *target;
+ int err;
+
+ pr_info("start\n");
+
+ ctx = damon_new_ctx();
+ if (!ctx)
+ return -ENOMEM;
+ if (damon_select_ops(ctx, DAMON_OPS_VADDR)) {
+ damon_destroy_ctx(ctx);
+ return -EINVAL;
+ }
+
+ target = damon_new_target();
+ if (!target) {
+ damon_destroy_ctx(ctx);
+ return -ENOMEM;
+ }
+ damon_add_target(ctx, target);
+ target_pidp = find_get_pid(target_pid);
+ if (!target_pidp) {
+ damon_destroy_ctx(ctx);
+ return -EINVAL;
+ }
+ target->pid = target_pidp;
+
+ err = damon_start(&ctx, 1, true);
+ if (err)
+ return err;
+ repeat_call_control.data = ctx;
+ return damon_call(ctx, &repeat_call_control);
+}
+
+static void damon_sample_wsse_stop(void)
+{
+ pr_info("stop\n");
+ if (ctx) {
+ damon_stop(&ctx, 1);
+ damon_destroy_ctx(ctx);
+ }
+}
+
+static int damon_sample_wsse_enable_store(
+ const char *val, const struct kernel_param *kp)
+{
+ bool is_enabled = enabled;
+ int err;
+
+ err = kstrtobool(val, &enabled);
+ if (err)
+ return err;
+
+ if (enabled == is_enabled)
+ return 0;
+
+ if (!damon_initialized())
+ return 0;
+
+ if (enabled) {
+ err = damon_sample_wsse_start();
+ if (err)
+ enabled = false;
+ return err;
+ }
+ damon_sample_wsse_stop();
+ return 0;
+}
+
+static int __init damon_sample_wsse_init(void)
+{
+ int err = 0;
+
+ if (!damon_initialized()) {
+ err = -ENOMEM;
+ if (enabled)
+ enabled = false;
+ }
+
+ if (enabled) {
+ err = damon_sample_wsse_start();
+ if (err)
+ enabled = false;
+ }
+ return err;
+}
+
+module_init(damon_sample_wsse_init);