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-rw-r--r--mm/damon/sysfs.c1829
1 files changed, 1829 insertions, 0 deletions
diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
new file mode 100644
index 0000000000..b317f51dcc
--- /dev/null
+++ b/mm/damon/sysfs.c
@@ -0,0 +1,1829 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DAMON sysfs Interface
+ *
+ * Copyright (c) 2022 SeongJae Park <sj@kernel.org>
+ */
+
+#include <linux/pid.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#include "sysfs-common.h"
+
+/*
+ * init region directory
+ */
+
+struct damon_sysfs_region {
+ struct kobject kobj;
+ struct damon_addr_range ar;
+};
+
+static struct damon_sysfs_region *damon_sysfs_region_alloc(void)
+{
+ return kzalloc(sizeof(struct damon_sysfs_region), GFP_KERNEL);
+}
+
+static ssize_t start_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ struct damon_sysfs_region *region = container_of(kobj,
+ struct damon_sysfs_region, kobj);
+
+ return sysfs_emit(buf, "%lu\n", region->ar.start);
+}
+
+static ssize_t start_store(struct kobject *kobj, struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct damon_sysfs_region *region = container_of(kobj,
+ struct damon_sysfs_region, kobj);
+ int err = kstrtoul(buf, 0, &region->ar.start);
+
+ return err ? err : count;
+}
+
+static ssize_t end_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ struct damon_sysfs_region *region = container_of(kobj,
+ struct damon_sysfs_region, kobj);
+
+ return sysfs_emit(buf, "%lu\n", region->ar.end);
+}
+
+static ssize_t end_store(struct kobject *kobj, struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct damon_sysfs_region *region = container_of(kobj,
+ struct damon_sysfs_region, kobj);
+ int err = kstrtoul(buf, 0, &region->ar.end);
+
+ return err ? err : count;
+}
+
+static void damon_sysfs_region_release(struct kobject *kobj)
+{
+ kfree(container_of(kobj, struct damon_sysfs_region, kobj));
+}
+
+static struct kobj_attribute damon_sysfs_region_start_attr =
+ __ATTR_RW_MODE(start, 0600);
+
+static struct kobj_attribute damon_sysfs_region_end_attr =
+ __ATTR_RW_MODE(end, 0600);
+
+static struct attribute *damon_sysfs_region_attrs[] = {
+ &damon_sysfs_region_start_attr.attr,
+ &damon_sysfs_region_end_attr.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(damon_sysfs_region);
+
+static const struct kobj_type damon_sysfs_region_ktype = {
+ .release = damon_sysfs_region_release,
+ .sysfs_ops = &kobj_sysfs_ops,
+ .default_groups = damon_sysfs_region_groups,
+};
+
+/*
+ * init_regions directory
+ */
+
+struct damon_sysfs_regions {
+ struct kobject kobj;
+ struct damon_sysfs_region **regions_arr;
+ int nr;
+};
+
+static struct damon_sysfs_regions *damon_sysfs_regions_alloc(void)
+{
+ return kzalloc(sizeof(struct damon_sysfs_regions), GFP_KERNEL);
+}
+
+static void damon_sysfs_regions_rm_dirs(struct damon_sysfs_regions *regions)
+{
+ struct damon_sysfs_region **regions_arr = regions->regions_arr;
+ int i;
+
+ for (i = 0; i < regions->nr; i++)
+ kobject_put(&regions_arr[i]->kobj);
+ regions->nr = 0;
+ kfree(regions_arr);
+ regions->regions_arr = NULL;
+}
+
+static int damon_sysfs_regions_add_dirs(struct damon_sysfs_regions *regions,
+ int nr_regions)
+{
+ struct damon_sysfs_region **regions_arr, *region;
+ int err, i;
+
+ damon_sysfs_regions_rm_dirs(regions);
+ if (!nr_regions)
+ return 0;
+
+ regions_arr = kmalloc_array(nr_regions, sizeof(*regions_arr),
+ GFP_KERNEL | __GFP_NOWARN);
+ if (!regions_arr)
+ return -ENOMEM;
+ regions->regions_arr = regions_arr;
+
+ for (i = 0; i < nr_regions; i++) {
+ region = damon_sysfs_region_alloc();
+ if (!region) {
+ damon_sysfs_regions_rm_dirs(regions);
+ return -ENOMEM;
+ }
+
+ err = kobject_init_and_add(&region->kobj,
+ &damon_sysfs_region_ktype, &regions->kobj,
+ "%d", i);
+ if (err) {
+ kobject_put(&region->kobj);
+ damon_sysfs_regions_rm_dirs(regions);
+ return err;
+ }
+
+ regions_arr[i] = region;
+ regions->nr++;
+ }
+ return 0;
+}
+
+static ssize_t nr_regions_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct damon_sysfs_regions *regions = container_of(kobj,
+ struct damon_sysfs_regions, kobj);
+
+ return sysfs_emit(buf, "%d\n", regions->nr);
+}
+
+static ssize_t nr_regions_store(struct kobject *kobj,
+ struct kobj_attribute *attr, const char *buf, size_t count)
+{
+ struct damon_sysfs_regions *regions;
+ int nr, err = kstrtoint(buf, 0, &nr);
+
+ if (err)
+ return err;
+ if (nr < 0)
+ return -EINVAL;
+
+ regions = container_of(kobj, struct damon_sysfs_regions, kobj);
+
+ if (!mutex_trylock(&damon_sysfs_lock))
+ return -EBUSY;
+ err = damon_sysfs_regions_add_dirs(regions, nr);
+ mutex_unlock(&damon_sysfs_lock);
+ if (err)
+ return err;
+
+ return count;
+}
+
+static void damon_sysfs_regions_release(struct kobject *kobj)
+{
+ kfree(container_of(kobj, struct damon_sysfs_regions, kobj));
+}
+
+static struct kobj_attribute damon_sysfs_regions_nr_attr =
+ __ATTR_RW_MODE(nr_regions, 0600);
+
+static struct attribute *damon_sysfs_regions_attrs[] = {
+ &damon_sysfs_regions_nr_attr.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(damon_sysfs_regions);
+
+static const struct kobj_type damon_sysfs_regions_ktype = {
+ .release = damon_sysfs_regions_release,
+ .sysfs_ops = &kobj_sysfs_ops,
+ .default_groups = damon_sysfs_regions_groups,
+};
+
+/*
+ * target directory
+ */
+
+struct damon_sysfs_target {
+ struct kobject kobj;
+ struct damon_sysfs_regions *regions;
+ int pid;
+};
+
+static struct damon_sysfs_target *damon_sysfs_target_alloc(void)
+{
+ return kzalloc(sizeof(struct damon_sysfs_target), GFP_KERNEL);
+}
+
+static int damon_sysfs_target_add_dirs(struct damon_sysfs_target *target)
+{
+ struct damon_sysfs_regions *regions = damon_sysfs_regions_alloc();
+ int err;
+
+ if (!regions)
+ return -ENOMEM;
+
+ err = kobject_init_and_add(&regions->kobj, &damon_sysfs_regions_ktype,
+ &target->kobj, "regions");
+ if (err)
+ kobject_put(&regions->kobj);
+ else
+ target->regions = regions;
+ return err;
+}
+
+static void damon_sysfs_target_rm_dirs(struct damon_sysfs_target *target)
+{
+ damon_sysfs_regions_rm_dirs(target->regions);
+ kobject_put(&target->regions->kobj);
+}
+
+static ssize_t pid_target_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct damon_sysfs_target *target = container_of(kobj,
+ struct damon_sysfs_target, kobj);
+
+ return sysfs_emit(buf, "%d\n", target->pid);
+}
+
+static ssize_t pid_target_store(struct kobject *kobj,
+ struct kobj_attribute *attr, const char *buf, size_t count)
+{
+ struct damon_sysfs_target *target = container_of(kobj,
+ struct damon_sysfs_target, kobj);
+ int err = kstrtoint(buf, 0, &target->pid);
+
+ if (err)
+ return -EINVAL;
+ return count;
+}
+
+static void damon_sysfs_target_release(struct kobject *kobj)
+{
+ kfree(container_of(kobj, struct damon_sysfs_target, kobj));
+}
+
+static struct kobj_attribute damon_sysfs_target_pid_attr =
+ __ATTR_RW_MODE(pid_target, 0600);
+
+static struct attribute *damon_sysfs_target_attrs[] = {
+ &damon_sysfs_target_pid_attr.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(damon_sysfs_target);
+
+static const struct kobj_type damon_sysfs_target_ktype = {
+ .release = damon_sysfs_target_release,
+ .sysfs_ops = &kobj_sysfs_ops,
+ .default_groups = damon_sysfs_target_groups,
+};
+
+/*
+ * targets directory
+ */
+
+struct damon_sysfs_targets {
+ struct kobject kobj;
+ struct damon_sysfs_target **targets_arr;
+ int nr;
+};
+
+static struct damon_sysfs_targets *damon_sysfs_targets_alloc(void)
+{
+ return kzalloc(sizeof(struct damon_sysfs_targets), GFP_KERNEL);
+}
+
+static void damon_sysfs_targets_rm_dirs(struct damon_sysfs_targets *targets)
+{
+ struct damon_sysfs_target **targets_arr = targets->targets_arr;
+ int i;
+
+ for (i = 0; i < targets->nr; i++) {
+ damon_sysfs_target_rm_dirs(targets_arr[i]);
+ kobject_put(&targets_arr[i]->kobj);
+ }
+ targets->nr = 0;
+ kfree(targets_arr);
+ targets->targets_arr = NULL;
+}
+
+static int damon_sysfs_targets_add_dirs(struct damon_sysfs_targets *targets,
+ int nr_targets)
+{
+ struct damon_sysfs_target **targets_arr, *target;
+ int err, i;
+
+ damon_sysfs_targets_rm_dirs(targets);
+ if (!nr_targets)
+ return 0;
+
+ targets_arr = kmalloc_array(nr_targets, sizeof(*targets_arr),
+ GFP_KERNEL | __GFP_NOWARN);
+ if (!targets_arr)
+ return -ENOMEM;
+ targets->targets_arr = targets_arr;
+
+ for (i = 0; i < nr_targets; i++) {
+ target = damon_sysfs_target_alloc();
+ if (!target) {
+ damon_sysfs_targets_rm_dirs(targets);
+ return -ENOMEM;
+ }
+
+ err = kobject_init_and_add(&target->kobj,
+ &damon_sysfs_target_ktype, &targets->kobj,
+ "%d", i);
+ if (err)
+ goto out;
+
+ err = damon_sysfs_target_add_dirs(target);
+ if (err)
+ goto out;
+
+ targets_arr[i] = target;
+ targets->nr++;
+ }
+ return 0;
+
+out:
+ damon_sysfs_targets_rm_dirs(targets);
+ kobject_put(&target->kobj);
+ return err;
+}
+
+static ssize_t nr_targets_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct damon_sysfs_targets *targets = container_of(kobj,
+ struct damon_sysfs_targets, kobj);
+
+ return sysfs_emit(buf, "%d\n", targets->nr);
+}
+
+static ssize_t nr_targets_store(struct kobject *kobj,
+ struct kobj_attribute *attr, const char *buf, size_t count)
+{
+ struct damon_sysfs_targets *targets;
+ int nr, err = kstrtoint(buf, 0, &nr);
+
+ if (err)
+ return err;
+ if (nr < 0)
+ return -EINVAL;
+
+ targets = container_of(kobj, struct damon_sysfs_targets, kobj);
+
+ if (!mutex_trylock(&damon_sysfs_lock))
+ return -EBUSY;
+ err = damon_sysfs_targets_add_dirs(targets, nr);
+ mutex_unlock(&damon_sysfs_lock);
+ if (err)
+ return err;
+
+ return count;
+}
+
+static void damon_sysfs_targets_release(struct kobject *kobj)
+{
+ kfree(container_of(kobj, struct damon_sysfs_targets, kobj));
+}
+
+static struct kobj_attribute damon_sysfs_targets_nr_attr =
+ __ATTR_RW_MODE(nr_targets, 0600);
+
+static struct attribute *damon_sysfs_targets_attrs[] = {
+ &damon_sysfs_targets_nr_attr.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(damon_sysfs_targets);
+
+static const struct kobj_type damon_sysfs_targets_ktype = {
+ .release = damon_sysfs_targets_release,
+ .sysfs_ops = &kobj_sysfs_ops,
+ .default_groups = damon_sysfs_targets_groups,
+};
+
+/*
+ * intervals directory
+ */
+
+struct damon_sysfs_intervals {
+ struct kobject kobj;
+ unsigned long sample_us;
+ unsigned long aggr_us;
+ unsigned long update_us;
+};
+
+static struct damon_sysfs_intervals *damon_sysfs_intervals_alloc(
+ unsigned long sample_us, unsigned long aggr_us,
+ unsigned long update_us)
+{
+ struct damon_sysfs_intervals *intervals = kmalloc(sizeof(*intervals),
+ GFP_KERNEL);
+
+ if (!intervals)
+ return NULL;
+
+ intervals->kobj = (struct kobject){};
+ intervals->sample_us = sample_us;
+ intervals->aggr_us = aggr_us;
+ intervals->update_us = update_us;
+ return intervals;
+}
+
+static ssize_t sample_us_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct damon_sysfs_intervals *intervals = container_of(kobj,
+ struct damon_sysfs_intervals, kobj);
+
+ return sysfs_emit(buf, "%lu\n", intervals->sample_us);
+}
+
+static ssize_t sample_us_store(struct kobject *kobj,
+ struct kobj_attribute *attr, const char *buf, size_t count)
+{
+ struct damon_sysfs_intervals *intervals = container_of(kobj,
+ struct damon_sysfs_intervals, kobj);
+ unsigned long us;
+ int err = kstrtoul(buf, 0, &us);
+
+ if (err)
+ return err;
+
+ intervals->sample_us = us;
+ return count;
+}
+
+static ssize_t aggr_us_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ struct damon_sysfs_intervals *intervals = container_of(kobj,
+ struct damon_sysfs_intervals, kobj);
+
+ return sysfs_emit(buf, "%lu\n", intervals->aggr_us);
+}
+
+static ssize_t aggr_us_store(struct kobject *kobj, struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct damon_sysfs_intervals *intervals = container_of(kobj,
+ struct damon_sysfs_intervals, kobj);
+ unsigned long us;
+ int err = kstrtoul(buf, 0, &us);
+
+ if (err)
+ return err;
+
+ intervals->aggr_us = us;
+ return count;
+}
+
+static ssize_t update_us_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct damon_sysfs_intervals *intervals = container_of(kobj,
+ struct damon_sysfs_intervals, kobj);
+
+ return sysfs_emit(buf, "%lu\n", intervals->update_us);
+}
+
+static ssize_t update_us_store(struct kobject *kobj,
+ struct kobj_attribute *attr, const char *buf, size_t count)
+{
+ struct damon_sysfs_intervals *intervals = container_of(kobj,
+ struct damon_sysfs_intervals, kobj);
+ unsigned long us;
+ int err = kstrtoul(buf, 0, &us);
+
+ if (err)
+ return err;
+
+ intervals->update_us = us;
+ return count;
+}
+
+static void damon_sysfs_intervals_release(struct kobject *kobj)
+{
+ kfree(container_of(kobj, struct damon_sysfs_intervals, kobj));
+}
+
+static struct kobj_attribute damon_sysfs_intervals_sample_us_attr =
+ __ATTR_RW_MODE(sample_us, 0600);
+
+static struct kobj_attribute damon_sysfs_intervals_aggr_us_attr =
+ __ATTR_RW_MODE(aggr_us, 0600);
+
+static struct kobj_attribute damon_sysfs_intervals_update_us_attr =
+ __ATTR_RW_MODE(update_us, 0600);
+
+static struct attribute *damon_sysfs_intervals_attrs[] = {
+ &damon_sysfs_intervals_sample_us_attr.attr,
+ &damon_sysfs_intervals_aggr_us_attr.attr,
+ &damon_sysfs_intervals_update_us_attr.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(damon_sysfs_intervals);
+
+static const struct kobj_type damon_sysfs_intervals_ktype = {
+ .release = damon_sysfs_intervals_release,
+ .sysfs_ops = &kobj_sysfs_ops,
+ .default_groups = damon_sysfs_intervals_groups,
+};
+
+/*
+ * monitoring_attrs directory
+ */
+
+struct damon_sysfs_attrs {
+ struct kobject kobj;
+ struct damon_sysfs_intervals *intervals;
+ struct damon_sysfs_ul_range *nr_regions_range;
+};
+
+static struct damon_sysfs_attrs *damon_sysfs_attrs_alloc(void)
+{
+ struct damon_sysfs_attrs *attrs = kmalloc(sizeof(*attrs), GFP_KERNEL);
+
+ if (!attrs)
+ return NULL;
+ attrs->kobj = (struct kobject){};
+ return attrs;
+}
+
+static int damon_sysfs_attrs_add_dirs(struct damon_sysfs_attrs *attrs)
+{
+ struct damon_sysfs_intervals *intervals;
+ struct damon_sysfs_ul_range *nr_regions_range;
+ int err;
+
+ intervals = damon_sysfs_intervals_alloc(5000, 100000, 60000000);
+ if (!intervals)
+ return -ENOMEM;
+
+ err = kobject_init_and_add(&intervals->kobj,
+ &damon_sysfs_intervals_ktype, &attrs->kobj,
+ "intervals");
+ if (err)
+ goto put_intervals_out;
+ attrs->intervals = intervals;
+
+ nr_regions_range = damon_sysfs_ul_range_alloc(10, 1000);
+ if (!nr_regions_range) {
+ err = -ENOMEM;
+ goto put_intervals_out;
+ }
+
+ err = kobject_init_and_add(&nr_regions_range->kobj,
+ &damon_sysfs_ul_range_ktype, &attrs->kobj,
+ "nr_regions");
+ if (err)
+ goto put_nr_regions_intervals_out;
+ attrs->nr_regions_range = nr_regions_range;
+ return 0;
+
+put_nr_regions_intervals_out:
+ kobject_put(&nr_regions_range->kobj);
+ attrs->nr_regions_range = NULL;
+put_intervals_out:
+ kobject_put(&intervals->kobj);
+ attrs->intervals = NULL;
+ return err;
+}
+
+static void damon_sysfs_attrs_rm_dirs(struct damon_sysfs_attrs *attrs)
+{
+ kobject_put(&attrs->nr_regions_range->kobj);
+ kobject_put(&attrs->intervals->kobj);
+}
+
+static void damon_sysfs_attrs_release(struct kobject *kobj)
+{
+ kfree(container_of(kobj, struct damon_sysfs_attrs, kobj));
+}
+
+static struct attribute *damon_sysfs_attrs_attrs[] = {
+ NULL,
+};
+ATTRIBUTE_GROUPS(damon_sysfs_attrs);
+
+static const struct kobj_type damon_sysfs_attrs_ktype = {
+ .release = damon_sysfs_attrs_release,
+ .sysfs_ops = &kobj_sysfs_ops,
+ .default_groups = damon_sysfs_attrs_groups,
+};
+
+/*
+ * context directory
+ */
+
+/* This should match with enum damon_ops_id */
+static const char * const damon_sysfs_ops_strs[] = {
+ "vaddr",
+ "fvaddr",
+ "paddr",
+};
+
+struct damon_sysfs_context {
+ struct kobject kobj;
+ enum damon_ops_id ops_id;
+ struct damon_sysfs_attrs *attrs;
+ struct damon_sysfs_targets *targets;
+ struct damon_sysfs_schemes *schemes;
+};
+
+static struct damon_sysfs_context *damon_sysfs_context_alloc(
+ enum damon_ops_id ops_id)
+{
+ struct damon_sysfs_context *context = kmalloc(sizeof(*context),
+ GFP_KERNEL);
+
+ if (!context)
+ return NULL;
+ context->kobj = (struct kobject){};
+ context->ops_id = ops_id;
+ return context;
+}
+
+static int damon_sysfs_context_set_attrs(struct damon_sysfs_context *context)
+{
+ struct damon_sysfs_attrs *attrs = damon_sysfs_attrs_alloc();
+ int err;
+
+ if (!attrs)
+ return -ENOMEM;
+ err = kobject_init_and_add(&attrs->kobj, &damon_sysfs_attrs_ktype,
+ &context->kobj, "monitoring_attrs");
+ if (err)
+ goto out;
+ err = damon_sysfs_attrs_add_dirs(attrs);
+ if (err)
+ goto out;
+ context->attrs = attrs;
+ return 0;
+
+out:
+ kobject_put(&attrs->kobj);
+ return err;
+}
+
+static int damon_sysfs_context_set_targets(struct damon_sysfs_context *context)
+{
+ struct damon_sysfs_targets *targets = damon_sysfs_targets_alloc();
+ int err;
+
+ if (!targets)
+ return -ENOMEM;
+ err = kobject_init_and_add(&targets->kobj, &damon_sysfs_targets_ktype,
+ &context->kobj, "targets");
+ if (err) {
+ kobject_put(&targets->kobj);
+ return err;
+ }
+ context->targets = targets;
+ return 0;
+}
+
+static int damon_sysfs_context_set_schemes(struct damon_sysfs_context *context)
+{
+ struct damon_sysfs_schemes *schemes = damon_sysfs_schemes_alloc();
+ int err;
+
+ if (!schemes)
+ return -ENOMEM;
+ err = kobject_init_and_add(&schemes->kobj, &damon_sysfs_schemes_ktype,
+ &context->kobj, "schemes");
+ if (err) {
+ kobject_put(&schemes->kobj);
+ return err;
+ }
+ context->schemes = schemes;
+ return 0;
+}
+
+static int damon_sysfs_context_add_dirs(struct damon_sysfs_context *context)
+{
+ int err;
+
+ err = damon_sysfs_context_set_attrs(context);
+ if (err)
+ return err;
+
+ err = damon_sysfs_context_set_targets(context);
+ if (err)
+ goto put_attrs_out;
+
+ err = damon_sysfs_context_set_schemes(context);
+ if (err)
+ goto put_targets_attrs_out;
+ return 0;
+
+put_targets_attrs_out:
+ kobject_put(&context->targets->kobj);
+ context->targets = NULL;
+put_attrs_out:
+ kobject_put(&context->attrs->kobj);
+ context->attrs = NULL;
+ return err;
+}
+
+static void damon_sysfs_context_rm_dirs(struct damon_sysfs_context *context)
+{
+ damon_sysfs_attrs_rm_dirs(context->attrs);
+ kobject_put(&context->attrs->kobj);
+ damon_sysfs_targets_rm_dirs(context->targets);
+ kobject_put(&context->targets->kobj);
+ damon_sysfs_schemes_rm_dirs(context->schemes);
+ kobject_put(&context->schemes->kobj);
+}
+
+static ssize_t avail_operations_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ enum damon_ops_id id;
+ int len = 0;
+
+ for (id = 0; id < NR_DAMON_OPS; id++) {
+ if (!damon_is_registered_ops(id))
+ continue;
+ len += sysfs_emit_at(buf, len, "%s\n",
+ damon_sysfs_ops_strs[id]);
+ }
+ return len;
+}
+
+static ssize_t operations_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct damon_sysfs_context *context = container_of(kobj,
+ struct damon_sysfs_context, kobj);
+
+ return sysfs_emit(buf, "%s\n", damon_sysfs_ops_strs[context->ops_id]);
+}
+
+static ssize_t operations_store(struct kobject *kobj,
+ struct kobj_attribute *attr, const char *buf, size_t count)
+{
+ struct damon_sysfs_context *context = container_of(kobj,
+ struct damon_sysfs_context, kobj);
+ enum damon_ops_id id;
+
+ for (id = 0; id < NR_DAMON_OPS; id++) {
+ if (sysfs_streq(buf, damon_sysfs_ops_strs[id])) {
+ context->ops_id = id;
+ return count;
+ }
+ }
+ return -EINVAL;
+}
+
+static void damon_sysfs_context_release(struct kobject *kobj)
+{
+ kfree(container_of(kobj, struct damon_sysfs_context, kobj));
+}
+
+static struct kobj_attribute damon_sysfs_context_avail_operations_attr =
+ __ATTR_RO_MODE(avail_operations, 0400);
+
+static struct kobj_attribute damon_sysfs_context_operations_attr =
+ __ATTR_RW_MODE(operations, 0600);
+
+static struct attribute *damon_sysfs_context_attrs[] = {
+ &damon_sysfs_context_avail_operations_attr.attr,
+ &damon_sysfs_context_operations_attr.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(damon_sysfs_context);
+
+static const struct kobj_type damon_sysfs_context_ktype = {
+ .release = damon_sysfs_context_release,
+ .sysfs_ops = &kobj_sysfs_ops,
+ .default_groups = damon_sysfs_context_groups,
+};
+
+/*
+ * contexts directory
+ */
+
+struct damon_sysfs_contexts {
+ struct kobject kobj;
+ struct damon_sysfs_context **contexts_arr;
+ int nr;
+};
+
+static struct damon_sysfs_contexts *damon_sysfs_contexts_alloc(void)
+{
+ return kzalloc(sizeof(struct damon_sysfs_contexts), GFP_KERNEL);
+}
+
+static void damon_sysfs_contexts_rm_dirs(struct damon_sysfs_contexts *contexts)
+{
+ struct damon_sysfs_context **contexts_arr = contexts->contexts_arr;
+ int i;
+
+ for (i = 0; i < contexts->nr; i++) {
+ damon_sysfs_context_rm_dirs(contexts_arr[i]);
+ kobject_put(&contexts_arr[i]->kobj);
+ }
+ contexts->nr = 0;
+ kfree(contexts_arr);
+ contexts->contexts_arr = NULL;
+}
+
+static int damon_sysfs_contexts_add_dirs(struct damon_sysfs_contexts *contexts,
+ int nr_contexts)
+{
+ struct damon_sysfs_context **contexts_arr, *context;
+ int err, i;
+
+ damon_sysfs_contexts_rm_dirs(contexts);
+ if (!nr_contexts)
+ return 0;
+
+ contexts_arr = kmalloc_array(nr_contexts, sizeof(*contexts_arr),
+ GFP_KERNEL | __GFP_NOWARN);
+ if (!contexts_arr)
+ return -ENOMEM;
+ contexts->contexts_arr = contexts_arr;
+
+ for (i = 0; i < nr_contexts; i++) {
+ context = damon_sysfs_context_alloc(DAMON_OPS_VADDR);
+ if (!context) {
+ damon_sysfs_contexts_rm_dirs(contexts);
+ return -ENOMEM;
+ }
+
+ err = kobject_init_and_add(&context->kobj,
+ &damon_sysfs_context_ktype, &contexts->kobj,
+ "%d", i);
+ if (err)
+ goto out;
+
+ err = damon_sysfs_context_add_dirs(context);
+ if (err)
+ goto out;
+
+ contexts_arr[i] = context;
+ contexts->nr++;
+ }
+ return 0;
+
+out:
+ damon_sysfs_contexts_rm_dirs(contexts);
+ kobject_put(&context->kobj);
+ return err;
+}
+
+static ssize_t nr_contexts_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct damon_sysfs_contexts *contexts = container_of(kobj,
+ struct damon_sysfs_contexts, kobj);
+
+ return sysfs_emit(buf, "%d\n", contexts->nr);
+}
+
+static ssize_t nr_contexts_store(struct kobject *kobj,
+ struct kobj_attribute *attr, const char *buf, size_t count)
+{
+ struct damon_sysfs_contexts *contexts;
+ int nr, err;
+
+ err = kstrtoint(buf, 0, &nr);
+ if (err)
+ return err;
+ /* TODO: support multiple contexts per kdamond */
+ if (nr < 0 || 1 < nr)
+ return -EINVAL;
+
+ contexts = container_of(kobj, struct damon_sysfs_contexts, kobj);
+ if (!mutex_trylock(&damon_sysfs_lock))
+ return -EBUSY;
+ err = damon_sysfs_contexts_add_dirs(contexts, nr);
+ mutex_unlock(&damon_sysfs_lock);
+ if (err)
+ return err;
+
+ return count;
+}
+
+static void damon_sysfs_contexts_release(struct kobject *kobj)
+{
+ kfree(container_of(kobj, struct damon_sysfs_contexts, kobj));
+}
+
+static struct kobj_attribute damon_sysfs_contexts_nr_attr
+ = __ATTR_RW_MODE(nr_contexts, 0600);
+
+static struct attribute *damon_sysfs_contexts_attrs[] = {
+ &damon_sysfs_contexts_nr_attr.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(damon_sysfs_contexts);
+
+static const struct kobj_type damon_sysfs_contexts_ktype = {
+ .release = damon_sysfs_contexts_release,
+ .sysfs_ops = &kobj_sysfs_ops,
+ .default_groups = damon_sysfs_contexts_groups,
+};
+
+/*
+ * kdamond directory
+ */
+
+struct damon_sysfs_kdamond {
+ struct kobject kobj;
+ struct damon_sysfs_contexts *contexts;
+ struct damon_ctx *damon_ctx;
+};
+
+static struct damon_sysfs_kdamond *damon_sysfs_kdamond_alloc(void)
+{
+ return kzalloc(sizeof(struct damon_sysfs_kdamond), GFP_KERNEL);
+}
+
+static int damon_sysfs_kdamond_add_dirs(struct damon_sysfs_kdamond *kdamond)
+{
+ struct damon_sysfs_contexts *contexts;
+ int err;
+
+ contexts = damon_sysfs_contexts_alloc();
+ if (!contexts)
+ return -ENOMEM;
+
+ err = kobject_init_and_add(&contexts->kobj,
+ &damon_sysfs_contexts_ktype, &kdamond->kobj,
+ "contexts");
+ if (err) {
+ kobject_put(&contexts->kobj);
+ return err;
+ }
+ kdamond->contexts = contexts;
+
+ return err;
+}
+
+static void damon_sysfs_kdamond_rm_dirs(struct damon_sysfs_kdamond *kdamond)
+{
+ damon_sysfs_contexts_rm_dirs(kdamond->contexts);
+ kobject_put(&kdamond->contexts->kobj);
+}
+
+static bool damon_sysfs_ctx_running(struct damon_ctx *ctx)
+{
+ bool running;
+
+ mutex_lock(&ctx->kdamond_lock);
+ running = ctx->kdamond != NULL;
+ mutex_unlock(&ctx->kdamond_lock);
+ return running;
+}
+
+/*
+ * enum damon_sysfs_cmd - Commands for a specific kdamond.
+ */
+enum damon_sysfs_cmd {
+ /* @DAMON_SYSFS_CMD_ON: Turn the kdamond on. */
+ DAMON_SYSFS_CMD_ON,
+ /* @DAMON_SYSFS_CMD_OFF: Turn the kdamond off. */
+ DAMON_SYSFS_CMD_OFF,
+ /* @DAMON_SYSFS_CMD_COMMIT: Update kdamond inputs. */
+ DAMON_SYSFS_CMD_COMMIT,
+ /*
+ * @DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS: Update scheme stats sysfs
+ * files.
+ */
+ DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS,
+ /*
+ * @DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_BYTES: Update
+ * tried_regions/total_bytes sysfs files for each scheme.
+ */
+ DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_BYTES,
+ /*
+ * @DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS: Update schemes tried
+ * regions
+ */
+ DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS,
+ /*
+ * @DAMON_SYSFS_CMD_CLEAR_SCHEMES_TRIED_REGIONS: Clear schemes tried
+ * regions
+ */
+ DAMON_SYSFS_CMD_CLEAR_SCHEMES_TRIED_REGIONS,
+ /*
+ * @NR_DAMON_SYSFS_CMDS: Total number of DAMON sysfs commands.
+ */
+ NR_DAMON_SYSFS_CMDS,
+};
+
+/* Should match with enum damon_sysfs_cmd */
+static const char * const damon_sysfs_cmd_strs[] = {
+ "on",
+ "off",
+ "commit",
+ "update_schemes_stats",
+ "update_schemes_tried_bytes",
+ "update_schemes_tried_regions",
+ "clear_schemes_tried_regions",
+};
+
+/*
+ * struct damon_sysfs_cmd_request - A request to the DAMON callback.
+ * @cmd: The command that needs to be handled by the callback.
+ * @kdamond: The kobject wrapper that associated to the kdamond thread.
+ *
+ * This structure represents a sysfs command request that need to access some
+ * DAMON context-internal data. Because DAMON context-internal data can be
+ * safely accessed from DAMON callbacks without additional synchronization, the
+ * request will be handled by the DAMON callback. None-``NULL`` @kdamond means
+ * the request is valid.
+ */
+struct damon_sysfs_cmd_request {
+ enum damon_sysfs_cmd cmd;
+ struct damon_sysfs_kdamond *kdamond;
+};
+
+/* Current DAMON callback request. Protected by damon_sysfs_lock. */
+static struct damon_sysfs_cmd_request damon_sysfs_cmd_request;
+
+static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ struct damon_sysfs_kdamond *kdamond = container_of(kobj,
+ struct damon_sysfs_kdamond, kobj);
+ struct damon_ctx *ctx = kdamond->damon_ctx;
+ bool running;
+
+ if (!ctx)
+ running = false;
+ else
+ running = damon_sysfs_ctx_running(ctx);
+
+ return sysfs_emit(buf, "%s\n", running ?
+ damon_sysfs_cmd_strs[DAMON_SYSFS_CMD_ON] :
+ damon_sysfs_cmd_strs[DAMON_SYSFS_CMD_OFF]);
+}
+
+static int damon_sysfs_set_attrs(struct damon_ctx *ctx,
+ struct damon_sysfs_attrs *sys_attrs)
+{
+ struct damon_sysfs_intervals *sys_intervals = sys_attrs->intervals;
+ struct damon_sysfs_ul_range *sys_nr_regions =
+ sys_attrs->nr_regions_range;
+ struct damon_attrs attrs = {
+ .sample_interval = sys_intervals->sample_us,
+ .aggr_interval = sys_intervals->aggr_us,
+ .ops_update_interval = sys_intervals->update_us,
+ .min_nr_regions = sys_nr_regions->min,
+ .max_nr_regions = sys_nr_regions->max,
+ };
+ return damon_set_attrs(ctx, &attrs);
+}
+
+static void damon_sysfs_destroy_targets(struct damon_ctx *ctx)
+{
+ struct damon_target *t, *next;
+ bool has_pid = damon_target_has_pid(ctx);
+
+ damon_for_each_target_safe(t, next, ctx) {
+ if (has_pid)
+ put_pid(t->pid);
+ damon_destroy_target(t);
+ }
+}
+
+static int damon_sysfs_set_regions(struct damon_target *t,
+ struct damon_sysfs_regions *sysfs_regions)
+{
+ struct damon_addr_range *ranges = kmalloc_array(sysfs_regions->nr,
+ sizeof(*ranges), GFP_KERNEL | __GFP_NOWARN);
+ int i, err = -EINVAL;
+
+ if (!ranges)
+ return -ENOMEM;
+ for (i = 0; i < sysfs_regions->nr; i++) {
+ struct damon_sysfs_region *sys_region =
+ sysfs_regions->regions_arr[i];
+
+ if (sys_region->ar.start > sys_region->ar.end)
+ goto out;
+
+ ranges[i].start = sys_region->ar.start;
+ ranges[i].end = sys_region->ar.end;
+ if (i == 0)
+ continue;
+ if (ranges[i - 1].end > ranges[i].start)
+ goto out;
+ }
+ err = damon_set_regions(t, ranges, sysfs_regions->nr);
+out:
+ kfree(ranges);
+ return err;
+
+}
+
+static int damon_sysfs_add_target(struct damon_sysfs_target *sys_target,
+ struct damon_ctx *ctx)
+{
+ struct damon_target *t = damon_new_target();
+ int err = -EINVAL;
+
+ if (!t)
+ return -ENOMEM;
+ damon_add_target(ctx, t);
+ if (damon_target_has_pid(ctx)) {
+ t->pid = find_get_pid(sys_target->pid);
+ if (!t->pid)
+ goto destroy_targets_out;
+ }
+ err = damon_sysfs_set_regions(t, sys_target->regions);
+ if (err)
+ goto destroy_targets_out;
+ return 0;
+
+destroy_targets_out:
+ damon_sysfs_destroy_targets(ctx);
+ return err;
+}
+
+static int damon_sysfs_update_target_pid(struct damon_target *target, int pid)
+{
+ struct pid *pid_new;
+
+ pid_new = find_get_pid(pid);
+ if (!pid_new)
+ return -EINVAL;
+
+ if (pid_new == target->pid) {
+ put_pid(pid_new);
+ return 0;
+ }
+
+ put_pid(target->pid);
+ target->pid = pid_new;
+ return 0;
+}
+
+static int damon_sysfs_update_target(struct damon_target *target,
+ struct damon_ctx *ctx,
+ struct damon_sysfs_target *sys_target)
+{
+ int err = 0;
+
+ if (damon_target_has_pid(ctx)) {
+ err = damon_sysfs_update_target_pid(target, sys_target->pid);
+ if (err)
+ return err;
+ }
+
+ /*
+ * Do monitoring target region boundary update only if one or more
+ * regions are set by the user. This is for keeping current monitoring
+ * target results and range easier, especially for dynamic monitoring
+ * target regions update ops like 'vaddr'.
+ */
+ if (sys_target->regions->nr)
+ err = damon_sysfs_set_regions(target, sys_target->regions);
+ return err;
+}
+
+static int damon_sysfs_set_targets(struct damon_ctx *ctx,
+ struct damon_sysfs_targets *sysfs_targets)
+{
+ struct damon_target *t, *next;
+ int i = 0, err;
+
+ /* Multiple physical address space monitoring targets makes no sense */
+ if (ctx->ops.id == DAMON_OPS_PADDR && sysfs_targets->nr > 1)
+ return -EINVAL;
+
+ damon_for_each_target_safe(t, next, ctx) {
+ if (i < sysfs_targets->nr) {
+ err = damon_sysfs_update_target(t, ctx,
+ sysfs_targets->targets_arr[i]);
+ if (err)
+ return err;
+ } else {
+ if (damon_target_has_pid(ctx))
+ put_pid(t->pid);
+ damon_destroy_target(t);
+ }
+ i++;
+ }
+
+ for (; i < sysfs_targets->nr; i++) {
+ struct damon_sysfs_target *st = sysfs_targets->targets_arr[i];
+
+ err = damon_sysfs_add_target(st, ctx);
+ if (err)
+ return err;
+ }
+ return 0;
+}
+
+static bool damon_sysfs_schemes_regions_updating;
+
+static void damon_sysfs_before_terminate(struct damon_ctx *ctx)
+{
+ struct damon_target *t, *next;
+ struct damon_sysfs_kdamond *kdamond;
+ enum damon_sysfs_cmd cmd;
+
+ /* damon_sysfs_schemes_update_regions_stop() might not yet called */
+ kdamond = damon_sysfs_cmd_request.kdamond;
+ cmd = damon_sysfs_cmd_request.cmd;
+ if (kdamond && ctx == kdamond->damon_ctx &&
+ (cmd == DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS ||
+ cmd == DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_BYTES) &&
+ damon_sysfs_schemes_regions_updating) {
+ damon_sysfs_schemes_update_regions_stop(ctx);
+ damon_sysfs_schemes_regions_updating = false;
+ mutex_unlock(&damon_sysfs_lock);
+ }
+
+ if (!damon_target_has_pid(ctx))
+ return;
+
+ mutex_lock(&ctx->kdamond_lock);
+ damon_for_each_target_safe(t, next, ctx) {
+ put_pid(t->pid);
+ damon_destroy_target(t);
+ }
+ mutex_unlock(&ctx->kdamond_lock);
+}
+
+/*
+ * damon_sysfs_upd_schemes_stats() - Update schemes stats sysfs files.
+ * @kdamond: The kobject wrapper that associated to the kdamond thread.
+ *
+ * This function reads the schemes stats of specific kdamond and update the
+ * related values for sysfs files. This function should be called from DAMON
+ * callbacks while holding ``damon_syfs_lock``, to safely access the DAMON
+ * contexts-internal data and DAMON sysfs variables.
+ */
+static int damon_sysfs_upd_schemes_stats(struct damon_sysfs_kdamond *kdamond)
+{
+ struct damon_ctx *ctx = kdamond->damon_ctx;
+
+ if (!ctx)
+ return -EINVAL;
+ damon_sysfs_schemes_update_stats(
+ kdamond->contexts->contexts_arr[0]->schemes, ctx);
+ return 0;
+}
+
+static int damon_sysfs_upd_schemes_regions_start(
+ struct damon_sysfs_kdamond *kdamond, bool total_bytes_only)
+{
+ struct damon_ctx *ctx = kdamond->damon_ctx;
+
+ if (!ctx)
+ return -EINVAL;
+ return damon_sysfs_schemes_update_regions_start(
+ kdamond->contexts->contexts_arr[0]->schemes, ctx,
+ total_bytes_only);
+}
+
+static int damon_sysfs_upd_schemes_regions_stop(
+ struct damon_sysfs_kdamond *kdamond)
+{
+ struct damon_ctx *ctx = kdamond->damon_ctx;
+
+ if (!ctx)
+ return -EINVAL;
+ return damon_sysfs_schemes_update_regions_stop(ctx);
+}
+
+static int damon_sysfs_clear_schemes_regions(
+ struct damon_sysfs_kdamond *kdamond)
+{
+ struct damon_ctx *ctx = kdamond->damon_ctx;
+
+ if (!ctx)
+ return -EINVAL;
+ return damon_sysfs_schemes_clear_regions(
+ kdamond->contexts->contexts_arr[0]->schemes, ctx);
+}
+
+static inline bool damon_sysfs_kdamond_running(
+ struct damon_sysfs_kdamond *kdamond)
+{
+ return kdamond->damon_ctx &&
+ damon_sysfs_ctx_running(kdamond->damon_ctx);
+}
+
+static int damon_sysfs_apply_inputs(struct damon_ctx *ctx,
+ struct damon_sysfs_context *sys_ctx)
+{
+ int err;
+
+ err = damon_select_ops(ctx, sys_ctx->ops_id);
+ if (err)
+ return err;
+ err = damon_sysfs_set_attrs(ctx, sys_ctx->attrs);
+ if (err)
+ return err;
+ err = damon_sysfs_set_targets(ctx, sys_ctx->targets);
+ if (err)
+ return err;
+ return damon_sysfs_set_schemes(ctx, sys_ctx->schemes);
+}
+
+/*
+ * damon_sysfs_commit_input() - Commit user inputs to a running kdamond.
+ * @kdamond: The kobject wrapper for the associated kdamond.
+ *
+ * If the sysfs input is wrong, the kdamond will be terminated.
+ */
+static int damon_sysfs_commit_input(struct damon_sysfs_kdamond *kdamond)
+{
+ if (!damon_sysfs_kdamond_running(kdamond))
+ return -EINVAL;
+ /* TODO: Support multiple contexts per kdamond */
+ if (kdamond->contexts->nr != 1)
+ return -EINVAL;
+
+ return damon_sysfs_apply_inputs(kdamond->damon_ctx,
+ kdamond->contexts->contexts_arr[0]);
+}
+
+/*
+ * damon_sysfs_cmd_request_callback() - DAMON callback for handling requests.
+ * @c: The DAMON context of the callback.
+ *
+ * This function is periodically called back from the kdamond thread for @c.
+ * Then, it checks if there is a waiting DAMON sysfs request and handles it.
+ */
+static int damon_sysfs_cmd_request_callback(struct damon_ctx *c)
+{
+ struct damon_sysfs_kdamond *kdamond;
+ bool total_bytes_only = false;
+ int err = 0;
+
+ /* avoid deadlock due to concurrent state_store('off') */
+ if (!damon_sysfs_schemes_regions_updating &&
+ !mutex_trylock(&damon_sysfs_lock))
+ return 0;
+ kdamond = damon_sysfs_cmd_request.kdamond;
+ if (!kdamond || kdamond->damon_ctx != c)
+ goto out;
+ switch (damon_sysfs_cmd_request.cmd) {
+ case DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS:
+ err = damon_sysfs_upd_schemes_stats(kdamond);
+ break;
+ case DAMON_SYSFS_CMD_COMMIT:
+ err = damon_sysfs_commit_input(kdamond);
+ break;
+ case DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_BYTES:
+ total_bytes_only = true;
+ fallthrough;
+ case DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS:
+ if (!damon_sysfs_schemes_regions_updating) {
+ err = damon_sysfs_upd_schemes_regions_start(kdamond,
+ total_bytes_only);
+ if (!err) {
+ damon_sysfs_schemes_regions_updating = true;
+ goto keep_lock_out;
+ }
+ } else {
+ err = damon_sysfs_upd_schemes_regions_stop(kdamond);
+ damon_sysfs_schemes_regions_updating = false;
+ }
+ break;
+ case DAMON_SYSFS_CMD_CLEAR_SCHEMES_TRIED_REGIONS:
+ err = damon_sysfs_clear_schemes_regions(kdamond);
+ break;
+ default:
+ break;
+ }
+ /* Mark the request as invalid now. */
+ damon_sysfs_cmd_request.kdamond = NULL;
+out:
+ if (!damon_sysfs_schemes_regions_updating)
+ mutex_unlock(&damon_sysfs_lock);
+keep_lock_out:
+ return err;
+}
+
+static struct damon_ctx *damon_sysfs_build_ctx(
+ struct damon_sysfs_context *sys_ctx)
+{
+ struct damon_ctx *ctx = damon_new_ctx();
+ int err;
+
+ if (!ctx)
+ return ERR_PTR(-ENOMEM);
+
+ err = damon_sysfs_apply_inputs(ctx, sys_ctx);
+ if (err) {
+ damon_destroy_ctx(ctx);
+ return ERR_PTR(err);
+ }
+
+ ctx->callback.after_wmarks_check = damon_sysfs_cmd_request_callback;
+ ctx->callback.after_aggregation = damon_sysfs_cmd_request_callback;
+ ctx->callback.before_terminate = damon_sysfs_before_terminate;
+ return ctx;
+}
+
+static int damon_sysfs_turn_damon_on(struct damon_sysfs_kdamond *kdamond)
+{
+ struct damon_ctx *ctx;
+ int err;
+
+ if (damon_sysfs_kdamond_running(kdamond))
+ return -EBUSY;
+ if (damon_sysfs_cmd_request.kdamond == kdamond)
+ return -EBUSY;
+ /* TODO: support multiple contexts per kdamond */
+ if (kdamond->contexts->nr != 1)
+ return -EINVAL;
+
+ if (kdamond->damon_ctx)
+ damon_destroy_ctx(kdamond->damon_ctx);
+ kdamond->damon_ctx = NULL;
+
+ ctx = damon_sysfs_build_ctx(kdamond->contexts->contexts_arr[0]);
+ if (IS_ERR(ctx))
+ return PTR_ERR(ctx);
+ err = damon_start(&ctx, 1, false);
+ if (err) {
+ damon_destroy_ctx(ctx);
+ return err;
+ }
+ kdamond->damon_ctx = ctx;
+ return err;
+}
+
+static int damon_sysfs_turn_damon_off(struct damon_sysfs_kdamond *kdamond)
+{
+ if (!kdamond->damon_ctx)
+ return -EINVAL;
+ return damon_stop(&kdamond->damon_ctx, 1);
+ /*
+ * To allow users show final monitoring results of already turned-off
+ * DAMON, we free kdamond->damon_ctx in next
+ * damon_sysfs_turn_damon_on(), or kdamonds_nr_store()
+ */
+}
+
+/*
+ * damon_sysfs_handle_cmd() - Handle a command for a specific kdamond.
+ * @cmd: The command to handle.
+ * @kdamond: The kobject wrapper for the associated kdamond.
+ *
+ * This function handles a DAMON sysfs command for a kdamond. For commands
+ * that need to access running DAMON context-internal data, it requests
+ * handling of the command to the DAMON callback
+ * (@damon_sysfs_cmd_request_callback()) and wait until it is properly handled,
+ * or the context is completed.
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+static int damon_sysfs_handle_cmd(enum damon_sysfs_cmd cmd,
+ struct damon_sysfs_kdamond *kdamond)
+{
+ bool need_wait = true;
+
+ /* Handle commands that doesn't access DAMON context-internal data */
+ switch (cmd) {
+ case DAMON_SYSFS_CMD_ON:
+ return damon_sysfs_turn_damon_on(kdamond);
+ case DAMON_SYSFS_CMD_OFF:
+ return damon_sysfs_turn_damon_off(kdamond);
+ default:
+ break;
+ }
+
+ /* Pass the command to DAMON callback for safe DAMON context access */
+ if (damon_sysfs_cmd_request.kdamond)
+ return -EBUSY;
+ if (!damon_sysfs_kdamond_running(kdamond))
+ return -EINVAL;
+ damon_sysfs_cmd_request.cmd = cmd;
+ damon_sysfs_cmd_request.kdamond = kdamond;
+
+ /*
+ * wait until damon_sysfs_cmd_request_callback() handles the request
+ * from kdamond context
+ */
+ mutex_unlock(&damon_sysfs_lock);
+ while (need_wait) {
+ schedule_timeout_idle(msecs_to_jiffies(100));
+ if (!mutex_trylock(&damon_sysfs_lock))
+ continue;
+ if (!damon_sysfs_cmd_request.kdamond) {
+ /* damon_sysfs_cmd_request_callback() handled */
+ need_wait = false;
+ } else if (!damon_sysfs_kdamond_running(kdamond)) {
+ /* kdamond has already finished */
+ need_wait = false;
+ damon_sysfs_cmd_request.kdamond = NULL;
+ }
+ mutex_unlock(&damon_sysfs_lock);
+ }
+ mutex_lock(&damon_sysfs_lock);
+ return 0;
+}
+
+static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct damon_sysfs_kdamond *kdamond = container_of(kobj,
+ struct damon_sysfs_kdamond, kobj);
+ enum damon_sysfs_cmd cmd;
+ ssize_t ret = -EINVAL;
+
+ if (!mutex_trylock(&damon_sysfs_lock))
+ return -EBUSY;
+ for (cmd = 0; cmd < NR_DAMON_SYSFS_CMDS; cmd++) {
+ if (sysfs_streq(buf, damon_sysfs_cmd_strs[cmd])) {
+ ret = damon_sysfs_handle_cmd(cmd, kdamond);
+ break;
+ }
+ }
+ mutex_unlock(&damon_sysfs_lock);
+ if (!ret)
+ ret = count;
+ return ret;
+}
+
+static ssize_t pid_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct damon_sysfs_kdamond *kdamond = container_of(kobj,
+ struct damon_sysfs_kdamond, kobj);
+ struct damon_ctx *ctx;
+ int pid = -1;
+
+ if (!mutex_trylock(&damon_sysfs_lock))
+ return -EBUSY;
+ ctx = kdamond->damon_ctx;
+ if (!ctx)
+ goto out;
+
+ mutex_lock(&ctx->kdamond_lock);
+ if (ctx->kdamond)
+ pid = ctx->kdamond->pid;
+ mutex_unlock(&ctx->kdamond_lock);
+out:
+ mutex_unlock(&damon_sysfs_lock);
+ return sysfs_emit(buf, "%d\n", pid);
+}
+
+static void damon_sysfs_kdamond_release(struct kobject *kobj)
+{
+ struct damon_sysfs_kdamond *kdamond = container_of(kobj,
+ struct damon_sysfs_kdamond, kobj);
+
+ if (kdamond->damon_ctx)
+ damon_destroy_ctx(kdamond->damon_ctx);
+ kfree(kdamond);
+}
+
+static struct kobj_attribute damon_sysfs_kdamond_state_attr =
+ __ATTR_RW_MODE(state, 0600);
+
+static struct kobj_attribute damon_sysfs_kdamond_pid_attr =
+ __ATTR_RO_MODE(pid, 0400);
+
+static struct attribute *damon_sysfs_kdamond_attrs[] = {
+ &damon_sysfs_kdamond_state_attr.attr,
+ &damon_sysfs_kdamond_pid_attr.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(damon_sysfs_kdamond);
+
+static const struct kobj_type damon_sysfs_kdamond_ktype = {
+ .release = damon_sysfs_kdamond_release,
+ .sysfs_ops = &kobj_sysfs_ops,
+ .default_groups = damon_sysfs_kdamond_groups,
+};
+
+/*
+ * kdamonds directory
+ */
+
+struct damon_sysfs_kdamonds {
+ struct kobject kobj;
+ struct damon_sysfs_kdamond **kdamonds_arr;
+ int nr;
+};
+
+static struct damon_sysfs_kdamonds *damon_sysfs_kdamonds_alloc(void)
+{
+ return kzalloc(sizeof(struct damon_sysfs_kdamonds), GFP_KERNEL);
+}
+
+static void damon_sysfs_kdamonds_rm_dirs(struct damon_sysfs_kdamonds *kdamonds)
+{
+ struct damon_sysfs_kdamond **kdamonds_arr = kdamonds->kdamonds_arr;
+ int i;
+
+ for (i = 0; i < kdamonds->nr; i++) {
+ damon_sysfs_kdamond_rm_dirs(kdamonds_arr[i]);
+ kobject_put(&kdamonds_arr[i]->kobj);
+ }
+ kdamonds->nr = 0;
+ kfree(kdamonds_arr);
+ kdamonds->kdamonds_arr = NULL;
+}
+
+static bool damon_sysfs_kdamonds_busy(struct damon_sysfs_kdamond **kdamonds,
+ int nr_kdamonds)
+{
+ int i;
+
+ for (i = 0; i < nr_kdamonds; i++) {
+ if (damon_sysfs_kdamond_running(kdamonds[i]) ||
+ damon_sysfs_cmd_request.kdamond == kdamonds[i])
+ return true;
+ }
+
+ return false;
+}
+
+static int damon_sysfs_kdamonds_add_dirs(struct damon_sysfs_kdamonds *kdamonds,
+ int nr_kdamonds)
+{
+ struct damon_sysfs_kdamond **kdamonds_arr, *kdamond;
+ int err, i;
+
+ if (damon_sysfs_kdamonds_busy(kdamonds->kdamonds_arr, kdamonds->nr))
+ return -EBUSY;
+
+ damon_sysfs_kdamonds_rm_dirs(kdamonds);
+ if (!nr_kdamonds)
+ return 0;
+
+ kdamonds_arr = kmalloc_array(nr_kdamonds, sizeof(*kdamonds_arr),
+ GFP_KERNEL | __GFP_NOWARN);
+ if (!kdamonds_arr)
+ return -ENOMEM;
+ kdamonds->kdamonds_arr = kdamonds_arr;
+
+ for (i = 0; i < nr_kdamonds; i++) {
+ kdamond = damon_sysfs_kdamond_alloc();
+ if (!kdamond) {
+ damon_sysfs_kdamonds_rm_dirs(kdamonds);
+ return -ENOMEM;
+ }
+
+ err = kobject_init_and_add(&kdamond->kobj,
+ &damon_sysfs_kdamond_ktype, &kdamonds->kobj,
+ "%d", i);
+ if (err)
+ goto out;
+
+ err = damon_sysfs_kdamond_add_dirs(kdamond);
+ if (err)
+ goto out;
+
+ kdamonds_arr[i] = kdamond;
+ kdamonds->nr++;
+ }
+ return 0;
+
+out:
+ damon_sysfs_kdamonds_rm_dirs(kdamonds);
+ kobject_put(&kdamond->kobj);
+ return err;
+}
+
+static ssize_t nr_kdamonds_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct damon_sysfs_kdamonds *kdamonds = container_of(kobj,
+ struct damon_sysfs_kdamonds, kobj);
+
+ return sysfs_emit(buf, "%d\n", kdamonds->nr);
+}
+
+static ssize_t nr_kdamonds_store(struct kobject *kobj,
+ struct kobj_attribute *attr, const char *buf, size_t count)
+{
+ struct damon_sysfs_kdamonds *kdamonds;
+ int nr, err;
+
+ err = kstrtoint(buf, 0, &nr);
+ if (err)
+ return err;
+ if (nr < 0)
+ return -EINVAL;
+
+ kdamonds = container_of(kobj, struct damon_sysfs_kdamonds, kobj);
+
+ if (!mutex_trylock(&damon_sysfs_lock))
+ return -EBUSY;
+ err = damon_sysfs_kdamonds_add_dirs(kdamonds, nr);
+ mutex_unlock(&damon_sysfs_lock);
+ if (err)
+ return err;
+
+ return count;
+}
+
+static void damon_sysfs_kdamonds_release(struct kobject *kobj)
+{
+ kfree(container_of(kobj, struct damon_sysfs_kdamonds, kobj));
+}
+
+static struct kobj_attribute damon_sysfs_kdamonds_nr_attr =
+ __ATTR_RW_MODE(nr_kdamonds, 0600);
+
+static struct attribute *damon_sysfs_kdamonds_attrs[] = {
+ &damon_sysfs_kdamonds_nr_attr.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(damon_sysfs_kdamonds);
+
+static const struct kobj_type damon_sysfs_kdamonds_ktype = {
+ .release = damon_sysfs_kdamonds_release,
+ .sysfs_ops = &kobj_sysfs_ops,
+ .default_groups = damon_sysfs_kdamonds_groups,
+};
+
+/*
+ * damon user interface directory
+ */
+
+struct damon_sysfs_ui_dir {
+ struct kobject kobj;
+ struct damon_sysfs_kdamonds *kdamonds;
+};
+
+static struct damon_sysfs_ui_dir *damon_sysfs_ui_dir_alloc(void)
+{
+ return kzalloc(sizeof(struct damon_sysfs_ui_dir), GFP_KERNEL);
+}
+
+static int damon_sysfs_ui_dir_add_dirs(struct damon_sysfs_ui_dir *ui_dir)
+{
+ struct damon_sysfs_kdamonds *kdamonds;
+ int err;
+
+ kdamonds = damon_sysfs_kdamonds_alloc();
+ if (!kdamonds)
+ return -ENOMEM;
+
+ err = kobject_init_and_add(&kdamonds->kobj,
+ &damon_sysfs_kdamonds_ktype, &ui_dir->kobj,
+ "kdamonds");
+ if (err) {
+ kobject_put(&kdamonds->kobj);
+ return err;
+ }
+ ui_dir->kdamonds = kdamonds;
+ return err;
+}
+
+static void damon_sysfs_ui_dir_release(struct kobject *kobj)
+{
+ kfree(container_of(kobj, struct damon_sysfs_ui_dir, kobj));
+}
+
+static struct attribute *damon_sysfs_ui_dir_attrs[] = {
+ NULL,
+};
+ATTRIBUTE_GROUPS(damon_sysfs_ui_dir);
+
+static const struct kobj_type damon_sysfs_ui_dir_ktype = {
+ .release = damon_sysfs_ui_dir_release,
+ .sysfs_ops = &kobj_sysfs_ops,
+ .default_groups = damon_sysfs_ui_dir_groups,
+};
+
+static int __init damon_sysfs_init(void)
+{
+ struct kobject *damon_sysfs_root;
+ struct damon_sysfs_ui_dir *admin;
+ int err;
+
+ damon_sysfs_root = kobject_create_and_add("damon", mm_kobj);
+ if (!damon_sysfs_root)
+ return -ENOMEM;
+
+ admin = damon_sysfs_ui_dir_alloc();
+ if (!admin) {
+ kobject_put(damon_sysfs_root);
+ return -ENOMEM;
+ }
+ err = kobject_init_and_add(&admin->kobj, &damon_sysfs_ui_dir_ktype,
+ damon_sysfs_root, "admin");
+ if (err)
+ goto out;
+ err = damon_sysfs_ui_dir_add_dirs(admin);
+ if (err)
+ goto out;
+ return 0;
+
+out:
+ kobject_put(&admin->kobj);
+ kobject_put(damon_sysfs_root);
+ return err;
+}
+subsys_initcall(damon_sysfs_init);