@@ -14,4 +14,17 @@ config SAMPLE_DAMON_WSSE
If unsure, say N.
+config SAMPLE_DAMON_PRCL
+ tristate "DAMON sameple 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 pid of a process, 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.
+
endmenu
@@ -1,2 +1,3 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_SAMPLE_DAMON_WSSE) += damon_sample_wsse.o
+obj-$(CONFIG_SAMPLE_DAMON_PRCL) += damon_sample_prcl.o
new file mode 100644
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * proactive reclamation: monitor access pattern of a given process, find
+ * regiosn 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>
+
+static int target_pid __read_mostly;
+module_param(target_pid, int, 0600);
+
+static struct damon_ctx *ctx;
+static struct pid *target_pidp;
+
+static int damon_sample_prcl_after_aggregate(struct damon_ctx *c)
+{
+ 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 int __init damon_sample_prcl_init(void)
+{
+ struct damon_target *target;
+ struct damos *scheme;
+
+ pr_info("Hello\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;
+
+ ctx->callback.after_aggregation = damon_sample_prcl_after_aggregate;
+
+ 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},
+ DAMOS_PAGEOUT,
+ 0,
+ &(struct damos_quota){},
+ &(struct damos_watermarks){});
+ if (!scheme) {
+ damon_destroy_ctx(ctx);
+ return -ENOMEM;
+ }
+ damon_set_schemes(ctx, &scheme, 1);
+
+ return damon_start(&ctx, 1, true);
+}
+
+static void __exit damon_sample_prcl_exit(void)
+{
+ pr_info("Goodbye\n");
+ if (ctx) {
+ damon_stop(&ctx, 1);
+ damon_destroy_ctx(ctx);
+ }
+ if (target_pidp)
+ put_pid(target_pidp);
+}
+
+module_init(damon_sample_prcl_init);
+module_exit(damon_sample_prcl_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("SeongJae Park");
+MODULE_DESCRIPTION("DAMON sample module for proactive reclamation");
Add a sample DAMON application kernel module, namely damon_sample_prcl. It is same to the one of the example kernel modules that presented at kernel summit 2021 with 10 minutes live coding[1] but updated for the latest DAMON interface. The sample module receives a pid of a process to monitor the access, monitors the access to the virtual address space of the process, find regions that not accessed and proactively reclaim those using DAMOS. [1] https://linuxplumbersconf.org/event/11/contributions/984/ Signed-off-by: SeongJae Park <sj@kernel.org> --- samples/damon/Kconfig | 13 ++++ samples/damon/Makefile | 1 + samples/damon/damon_sample_prcl.c | 102 ++++++++++++++++++++++++++++++ 3 files changed, 116 insertions(+) create mode 100644 samples/damon/damon_sample_prcl.c