2022-09-13 18:40:05

by SeongJae Park

[permalink] [raw]
Subject: [PATCH 05/22] mm/damon/core: use a dedicated struct for monitoring attributes

DAMON monitoring attributes are directly defined as fields of 'struct
damon_ctx'. This makes 'struct damon_ctx' a little long and
complicated. This commit defines and uses a struct, 'struct
damon_attrs', which is dedicated for only the monitoring attributes to
make the purpose of the five values clearer and simplify 'struct
damon_ctx'.

Signed-off-by: SeongJae Park <[email protected]>
---
include/linux/damon.h | 30 ++++++++++++++++++++----------
mm/damon/core.c | 34 +++++++++++++++++-----------------
mm/damon/dbgfs.c | 6 +++---
mm/damon/ops-common.c | 4 ++--
mm/damon/vaddr.c | 4 ++--
5 files changed, 44 insertions(+), 34 deletions(-)

diff --git a/include/linux/damon.h b/include/linux/damon.h
index 016b6c9c03d6..2ceee8b07726 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -389,13 +389,15 @@ struct damon_callback {
};

/**
- * struct damon_ctx - Represents a context for each monitoring. This is the
- * main interface that allows users to set the attributes and get the results
- * of the monitoring.
+ * struct damon_attrs - Monitoring attributes for accuracy/overhead control.
*
* @sample_interval: The time between access samplings.
* @aggr_interval: The time between monitor results aggregations.
* @ops_update_interval: The time between monitoring operations updates.
+ * @min_nr_regions: The minimum number of adaptive monitoring
+ * regions.
+ * @max_nr_regions: The maximum number of adaptive monitoring
+ * regions.
*
* For each @sample_interval, DAMON checks whether each region is accessed or
* not. It aggregates and keeps the access information (number of accesses to
@@ -405,7 +407,21 @@ struct damon_callback {
* @ops_update_interval. All time intervals are in micro-seconds.
* Please refer to &struct damon_operations and &struct damon_callback for more
* detail.
+ */
+struct damon_attrs {
+ unsigned long sample_interval;
+ unsigned long aggr_interval;
+ unsigned long ops_update_interval;
+ unsigned long min_nr_regions;
+ unsigned long max_nr_regions;
+};
+
+/**
+ * struct damon_ctx - Represents a context for each monitoring. This is the
+ * main interface that allows users to set the attributes and get the results
+ * of the monitoring.
*
+ * @attrs: Monitoring attributes for accuracy/overhead control.
* @kdamond: Kernel thread who does the monitoring.
* @kdamond_lock: Mutex for the synchronizations with @kdamond.
*
@@ -427,15 +443,11 @@ struct damon_callback {
* @ops: Set of monitoring operations for given use cases.
* @callback: Set of callbacks for monitoring events notifications.
*
- * @min_nr_regions: The minimum number of adaptive monitoring regions.
- * @max_nr_regions: The maximum number of adaptive monitoring regions.
* @adaptive_targets: Head of monitoring targets (&damon_target) list.
* @schemes: Head of schemes (&damos) list.
*/
struct damon_ctx {
- unsigned long sample_interval;
- unsigned long aggr_interval;
- unsigned long ops_update_interval;
+ struct damon_attrs attrs;

/* private: internal use only */
struct timespec64 last_aggregation;
@@ -448,8 +460,6 @@ struct damon_ctx {
struct damon_operations ops;
struct damon_callback callback;

- unsigned long min_nr_regions;
- unsigned long max_nr_regions;
struct list_head adaptive_targets;
struct list_head schemes;
};
diff --git a/mm/damon/core.c b/mm/damon/core.c
index 6767580c0a27..1f43ea9d956c 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -405,17 +405,17 @@ struct damon_ctx *damon_new_ctx(void)
if (!ctx)
return NULL;

- ctx->sample_interval = 5 * 1000;
- ctx->aggr_interval = 100 * 1000;
- ctx->ops_update_interval = 60 * 1000 * 1000;
+ ctx->attrs.sample_interval = 5 * 1000;
+ ctx->attrs.aggr_interval = 100 * 1000;
+ ctx->attrs.ops_update_interval = 60 * 1000 * 1000;

ktime_get_coarse_ts64(&ctx->last_aggregation);
ctx->last_ops_update = ctx->last_aggregation;

mutex_init(&ctx->kdamond_lock);

- ctx->min_nr_regions = 10;
- ctx->max_nr_regions = 1000;
+ ctx->attrs.min_nr_regions = 10;
+ ctx->attrs.max_nr_regions = 1000;

INIT_LIST_HEAD(&ctx->adaptive_targets);
INIT_LIST_HEAD(&ctx->schemes);
@@ -471,11 +471,11 @@ int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int,
if (min_nr_reg > max_nr_reg)
return -EINVAL;

- ctx->sample_interval = sample_int;
- ctx->aggr_interval = aggr_int;
- ctx->ops_update_interval = ops_upd_int;
- ctx->min_nr_regions = min_nr_reg;
- ctx->max_nr_regions = max_nr_reg;
+ ctx->attrs.sample_interval = sample_int;
+ ctx->attrs.aggr_interval = aggr_int;
+ ctx->attrs.ops_update_interval = ops_upd_int;
+ ctx->attrs.min_nr_regions = min_nr_reg;
+ ctx->attrs.max_nr_regions = max_nr_reg;

return 0;
}
@@ -530,8 +530,8 @@ static unsigned long damon_region_sz_limit(struct damon_ctx *ctx)
sz += r->ar.end - r->ar.start;
}

- if (ctx->min_nr_regions)
- sz /= ctx->min_nr_regions;
+ if (ctx->attrs.min_nr_regions)
+ sz /= ctx->attrs.min_nr_regions;
if (sz < DAMON_MIN_REGION)
sz = DAMON_MIN_REGION;

@@ -680,7 +680,7 @@ static bool damon_check_reset_time_interval(struct timespec64 *baseline,
static bool kdamond_aggregate_interval_passed(struct damon_ctx *ctx)
{
return damon_check_reset_time_interval(&ctx->last_aggregation,
- ctx->aggr_interval);
+ ctx->attrs.aggr_interval);
}

/*
@@ -1062,12 +1062,12 @@ static void kdamond_split_regions(struct damon_ctx *ctx)
damon_for_each_target(t, ctx)
nr_regions += damon_nr_regions(t);

- if (nr_regions > ctx->max_nr_regions / 2)
+ if (nr_regions > ctx->attrs.max_nr_regions / 2)
return;

/* Maybe the middle of the region has different access frequency */
if (last_nr_regions == nr_regions &&
- nr_regions < ctx->max_nr_regions / 3)
+ nr_regions < ctx->attrs.max_nr_regions / 3)
nr_subregions = 3;

damon_for_each_target(t, ctx)
@@ -1085,7 +1085,7 @@ static void kdamond_split_regions(struct damon_ctx *ctx)
static bool kdamond_need_update_operations(struct damon_ctx *ctx)
{
return damon_check_reset_time_interval(&ctx->last_ops_update,
- ctx->ops_update_interval);
+ ctx->attrs.ops_update_interval);
}

/*
@@ -1229,7 +1229,7 @@ static int kdamond_fn(void *data)
ctx->callback.after_sampling(ctx))
break;

- kdamond_usleep(ctx->sample_interval);
+ kdamond_usleep(ctx->attrs.sample_interval);

if (ctx->ops.check_accesses)
max_nr_accesses = ctx->ops.check_accesses(ctx);
diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c
index 1422037cedd2..74e7542af6d3 100644
--- a/mm/damon/dbgfs.c
+++ b/mm/damon/dbgfs.c
@@ -55,9 +55,9 @@ static ssize_t dbgfs_attrs_read(struct file *file,

mutex_lock(&ctx->kdamond_lock);
ret = scnprintf(kbuf, ARRAY_SIZE(kbuf), "%lu %lu %lu %lu %lu\n",
- ctx->sample_interval, ctx->aggr_interval,
- ctx->ops_update_interval, ctx->min_nr_regions,
- ctx->max_nr_regions);
+ ctx->attrs.sample_interval, ctx->attrs.aggr_interval,
+ ctx->attrs.ops_update_interval,
+ ctx->attrs.min_nr_regions, ctx->attrs.max_nr_regions);
mutex_unlock(&ctx->kdamond_lock);

return simple_read_from_buffer(buf, count, ppos, kbuf, ret);
diff --git a/mm/damon/ops-common.c b/mm/damon/ops-common.c
index f599838b5f64..9310df72e1c5 100644
--- a/mm/damon/ops-common.c
+++ b/mm/damon/ops-common.c
@@ -99,10 +99,10 @@ int damon_hot_score(struct damon_ctx *c, struct damon_region *r,
unsigned int age_weight = s->quota.weight_age;
int hotness;

- max_nr_accesses = c->aggr_interval / c->sample_interval;
+ max_nr_accesses = c->attrs.aggr_interval / c->attrs.sample_interval;
freq_subscore = r->nr_accesses * DAMON_MAX_SUBSCORE / max_nr_accesses;

- age_in_sec = (unsigned long)r->age * c->aggr_interval / 1000000;
+ age_in_sec = (unsigned long)r->age * c->attrs.aggr_interval / 1000000;
for (age_in_log = 0; age_in_log < DAMON_MAX_AGE_IN_LOG && age_in_sec;
age_in_log++, age_in_sec >>= 1)
;
diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c
index 39ea48d9cc15..3f84584f9982 100644
--- a/mm/damon/vaddr.c
+++ b/mm/damon/vaddr.c
@@ -251,8 +251,8 @@ static void __damon_va_init_regions(struct damon_ctx *ctx,

for (i = 0; i < 3; i++)
sz += regions[i].end - regions[i].start;
- if (ctx->min_nr_regions)
- sz /= ctx->min_nr_regions;
+ if (ctx->attrs.min_nr_regions)
+ sz /= ctx->attrs.min_nr_regions;
if (sz < DAMON_MIN_REGION)
sz = DAMON_MIN_REGION;

--
2.25.1