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-rw-r--r--mm/Kconfig2
-rw-r--r--mm/Makefile1
-rw-r--r--mm/damon/Kconfig15
-rw-r--r--mm/damon/Makefile3
-rw-r--r--mm/damon/core.c320
5 files changed, 341 insertions, 0 deletions
diff --git a/mm/Kconfig b/mm/Kconfig
index 14d5d2837737..8459167b0294 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -886,4 +886,6 @@ config IO_MAPPING
config SECRETMEM
def_bool ARCH_HAS_SET_DIRECT_MAP && !EMBEDDED
+source "mm/damon/Kconfig"
+
endmenu
diff --git a/mm/Makefile b/mm/Makefile
index 0e0a5a6fe127..fc60a40ce954 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -118,6 +118,7 @@ obj-$(CONFIG_CMA_SYSFS) += cma_sysfs.o
obj-$(CONFIG_USERFAULTFD) += userfaultfd.o
obj-$(CONFIG_IDLE_PAGE_TRACKING) += page_idle.o
obj-$(CONFIG_DEBUG_PAGE_REF) += debug_page_ref.o
+obj-$(CONFIG_DAMON) += damon/
obj-$(CONFIG_HARDENED_USERCOPY) += usercopy.o
obj-$(CONFIG_PERCPU_STATS) += percpu-stats.o
obj-$(CONFIG_ZONE_DEVICE) += memremap.o
diff --git a/mm/damon/Kconfig b/mm/damon/Kconfig
new file mode 100644
index 000000000000..d00e99ac1a15
--- /dev/null
+++ b/mm/damon/Kconfig
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+menu "Data Access Monitoring"
+
+config DAMON
+ bool "DAMON: Data Access Monitoring Framework"
+ help
+ This builds a framework that allows kernel subsystems to monitor
+ access frequency of each memory region. The information can be useful
+ for performance-centric DRAM level memory management.
+
+ See https://damonitor.github.io/doc/html/latest-damon/index.html for
+ more information.
+
+endmenu
diff --git a/mm/damon/Makefile b/mm/damon/Makefile
new file mode 100644
index 000000000000..4fd2edb4becf
--- /dev/null
+++ b/mm/damon/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_DAMON) := core.o
diff --git a/mm/damon/core.c b/mm/damon/core.c
new file mode 100644
index 000000000000..651590bf49b1
--- /dev/null
+++ b/mm/damon/core.c
@@ -0,0 +1,320 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Data Access Monitor
+ *
+ * Author: SeongJae Park <sjpark@amazon.de>
+ */
+
+#define pr_fmt(fmt) "damon: " fmt
+
+#include <linux/damon.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+#include <linux/slab.h>
+
+static DEFINE_MUTEX(damon_lock);
+static int nr_running_ctxs;
+
+struct damon_ctx *damon_new_ctx(void)
+{
+ struct damon_ctx *ctx;
+
+ ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return NULL;
+
+ ctx->sample_interval = 5 * 1000;
+ ctx->aggr_interval = 100 * 1000;
+ ctx->primitive_update_interval = 60 * 1000 * 1000;
+
+ ktime_get_coarse_ts64(&ctx->last_aggregation);
+ ctx->last_primitive_update = ctx->last_aggregation;
+
+ mutex_init(&ctx->kdamond_lock);
+
+ ctx->target = NULL;
+
+ return ctx;
+}
+
+void damon_destroy_ctx(struct damon_ctx *ctx)
+{
+ if (ctx->primitive.cleanup)
+ ctx->primitive.cleanup(ctx);
+ kfree(ctx);
+}
+
+/**
+ * damon_set_attrs() - Set attributes for the monitoring.
+ * @ctx: monitoring context
+ * @sample_int: time interval between samplings
+ * @aggr_int: time interval between aggregations
+ * @primitive_upd_int: time interval between monitoring primitive updates
+ *
+ * This function should not be called while the kdamond is running.
+ * Every time interval is in micro-seconds.
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int,
+ unsigned long aggr_int, unsigned long primitive_upd_int)
+{
+ ctx->sample_interval = sample_int;
+ ctx->aggr_interval = aggr_int;
+ ctx->primitive_update_interval = primitive_upd_int;
+
+ return 0;
+}
+
+static bool damon_kdamond_running(struct damon_ctx *ctx)
+{
+ bool running;
+
+ mutex_lock(&ctx->kdamond_lock);
+ running = ctx->kdamond != NULL;
+ mutex_unlock(&ctx->kdamond_lock);
+
+ return running;
+}
+
+static int kdamond_fn(void *data);
+
+/*
+ * __damon_start() - Starts monitoring with given context.
+ * @ctx: monitoring context
+ *
+ * This function should be called while damon_lock is hold.
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+static int __damon_start(struct damon_ctx *ctx)
+{
+ int err = -EBUSY;
+
+ mutex_lock(&ctx->kdamond_lock);
+ if (!ctx->kdamond) {
+ err = 0;
+ ctx->kdamond_stop = false;
+ ctx->kdamond = kthread_run(kdamond_fn, ctx, "kdamond.%d",
+ nr_running_ctxs);
+ if (IS_ERR(ctx->kdamond)) {
+ err = PTR_ERR(ctx->kdamond);
+ ctx->kdamond = 0;
+ }
+ }
+ mutex_unlock(&ctx->kdamond_lock);
+
+ return err;
+}
+
+/**
+ * damon_start() - Starts the monitorings for a given group of contexts.
+ * @ctxs: an array of the pointers for contexts to start monitoring
+ * @nr_ctxs: size of @ctxs
+ *
+ * This function starts a group of monitoring threads for a group of monitoring
+ * contexts. One thread per each context is created and run in parallel. The
+ * caller should handle synchronization between the threads by itself. If a
+ * group of threads that created by other 'damon_start()' call is currently
+ * running, this function does nothing but returns -EBUSY.
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+int damon_start(struct damon_ctx **ctxs, int nr_ctxs)
+{
+ int i;
+ int err = 0;
+
+ mutex_lock(&damon_lock);
+ if (nr_running_ctxs) {
+ mutex_unlock(&damon_lock);
+ return -EBUSY;
+ }
+
+ for (i = 0; i < nr_ctxs; i++) {
+ err = __damon_start(ctxs[i]);
+ if (err)
+ break;
+ nr_running_ctxs++;
+ }
+ mutex_unlock(&damon_lock);
+
+ return err;
+}
+
+/*
+ * __damon_stop() - Stops monitoring of given context.
+ * @ctx: monitoring context
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+static int __damon_stop(struct damon_ctx *ctx)
+{
+ mutex_lock(&ctx->kdamond_lock);
+ if (ctx->kdamond) {
+ ctx->kdamond_stop = true;
+ mutex_unlock(&ctx->kdamond_lock);
+ while (damon_kdamond_running(ctx))
+ usleep_range(ctx->sample_interval,
+ ctx->sample_interval * 2);
+ return 0;
+ }
+ mutex_unlock(&ctx->kdamond_lock);
+
+ return -EPERM;
+}
+
+/**
+ * damon_stop() - Stops the monitorings for a given group of contexts.
+ * @ctxs: an array of the pointers for contexts to stop monitoring
+ * @nr_ctxs: size of @ctxs
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+int damon_stop(struct damon_ctx **ctxs, int nr_ctxs)
+{
+ int i, err = 0;
+
+ for (i = 0; i < nr_ctxs; i++) {
+ /* nr_running_ctxs is decremented in kdamond_fn */
+ err = __damon_stop(ctxs[i]);
+ if (err)
+ return err;
+ }
+
+ return err;
+}
+
+/*
+ * damon_check_reset_time_interval() - Check if a time interval is elapsed.
+ * @baseline: the time to check whether the interval has elapsed since
+ * @interval: the time interval (microseconds)
+ *
+ * See whether the given time interval has passed since the given baseline
+ * time. If so, it also updates the baseline to current time for next check.
+ *
+ * Return: true if the time interval has passed, or false otherwise.
+ */
+static bool damon_check_reset_time_interval(struct timespec64 *baseline,
+ unsigned long interval)
+{
+ struct timespec64 now;
+
+ ktime_get_coarse_ts64(&now);
+ if ((timespec64_to_ns(&now) - timespec64_to_ns(baseline)) <
+ interval * 1000)
+ return false;
+ *baseline = now;
+ return true;
+}
+
+/*
+ * Check whether it is time to flush the aggregated information
+ */
+static bool kdamond_aggregate_interval_passed(struct damon_ctx *ctx)
+{
+ return damon_check_reset_time_interval(&ctx->last_aggregation,
+ ctx->aggr_interval);
+}
+
+/*
+ * Check whether it is time to check and apply the target monitoring regions
+ *
+ * Returns true if it is.
+ */
+static bool kdamond_need_update_primitive(struct damon_ctx *ctx)
+{
+ return damon_check_reset_time_interval(&ctx->last_primitive_update,
+ ctx->primitive_update_interval);
+}
+
+/*
+ * Check whether current monitoring should be stopped
+ *
+ * The monitoring is stopped when either the user requested to stop, or all
+ * monitoring targets are invalid.
+ *
+ * Returns true if need to stop current monitoring.
+ */
+static bool kdamond_need_stop(struct damon_ctx *ctx)
+{
+ bool stop;
+
+ mutex_lock(&ctx->kdamond_lock);
+ stop = ctx->kdamond_stop;
+ mutex_unlock(&ctx->kdamond_lock);
+ if (stop)
+ return true;
+
+ if (!ctx->primitive.target_valid)
+ return false;
+
+ return !ctx->primitive.target_valid(ctx->target);
+}
+
+static void set_kdamond_stop(struct damon_ctx *ctx)
+{
+ mutex_lock(&ctx->kdamond_lock);
+ ctx->kdamond_stop = true;
+ mutex_unlock(&ctx->kdamond_lock);
+}
+
+/*
+ * The monitoring daemon that runs as a kernel thread
+ */
+static int kdamond_fn(void *data)
+{
+ struct damon_ctx *ctx = (struct damon_ctx *)data;
+
+ mutex_lock(&ctx->kdamond_lock);
+ pr_info("kdamond (%d) starts\n", ctx->kdamond->pid);
+ mutex_unlock(&ctx->kdamond_lock);
+
+ if (ctx->primitive.init)
+ ctx->primitive.init(ctx);
+ if (ctx->callback.before_start && ctx->callback.before_start(ctx))
+ set_kdamond_stop(ctx);
+
+ while (!kdamond_need_stop(ctx)) {
+ if (ctx->primitive.prepare_access_checks)
+ ctx->primitive.prepare_access_checks(ctx);
+ if (ctx->callback.after_sampling &&
+ ctx->callback.after_sampling(ctx))
+ set_kdamond_stop(ctx);
+
+ usleep_range(ctx->sample_interval, ctx->sample_interval + 1);
+
+ if (ctx->primitive.check_accesses)
+ ctx->primitive.check_accesses(ctx);
+
+ if (kdamond_aggregate_interval_passed(ctx)) {
+ if (ctx->callback.after_aggregation &&
+ ctx->callback.after_aggregation(ctx))
+ set_kdamond_stop(ctx);
+ if (ctx->primitive.reset_aggregated)
+ ctx->primitive.reset_aggregated(ctx);
+ }
+
+ if (kdamond_need_update_primitive(ctx)) {
+ if (ctx->primitive.update)
+ ctx->primitive.update(ctx);
+ }
+ }
+
+ if (ctx->callback.before_terminate &&
+ ctx->callback.before_terminate(ctx))
+ set_kdamond_stop(ctx);
+ if (ctx->primitive.cleanup)
+ ctx->primitive.cleanup(ctx);
+
+ pr_debug("kdamond (%d) finishes\n", ctx->kdamond->pid);
+ mutex_lock(&ctx->kdamond_lock);
+ ctx->kdamond = NULL;
+ mutex_unlock(&ctx->kdamond_lock);
+
+ mutex_lock(&damon_lock);
+ nr_running_ctxs--;
+ mutex_unlock(&damon_lock);
+
+ do_exit(0);
+}
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-11-25 00:28:33 +0000