[RFC PATCH 04/13] mm/damon/dbgfs: Support schemes speed limit

From: sj38 . park
Date: Mon May 31 2021 - 10:58:43 EST


From: SeongJae Park <sjpark@xxxxxxxxx>

This commit makes the debugfs interface of DAMON to support the schemes
speed limit by chaning the format of the input for the schemes file.

Signed-off-by: SeongJae Park <sjpark@xxxxxxxxx>
---
mm/damon/dbgfs.c | 30 +++++++++++++++++++++++-------
1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c
index 4b45b69db697..ea6d4fdb57fa 100644
--- a/mm/damon/dbgfs.c
+++ b/mm/damon/dbgfs.c
@@ -227,11 +227,12 @@ static ssize_t sprint_schemes(struct damon_ctx *c, char *buf, ssize_t len)

damon_for_each_scheme(s, c) {
rc = scnprintf(&buf[written], len - written,
- "%lu %lu %u %u %u %u %d %lu %lu\n",
+ "%lu %lu %u %u %u %u %d %lu %lu %lu %lu\n",
s->min_sz_region, s->max_sz_region,
s->min_nr_accesses, s->max_nr_accesses,
s->min_age_region, s->max_age_region,
- s->action, s->stat_count, s->stat_sz);
+ s->action, s->limit.sz, s->limit.ms,
+ s->stat_count, s->stat_sz);
if (!rc)
return -ENOMEM;

@@ -312,10 +313,11 @@ static struct damos **str_to_schemes(const char *str, ssize_t len,
while (pos < len && *nr_schemes < max_nr_schemes) {
struct damos_speed_limit limit = {};

- ret = sscanf(&str[pos], "%lu %lu %u %u %u %u %u%n",
+ ret = sscanf(&str[pos], "%lu %lu %u %u %u %u %u %lu %lu%n",
&min_sz, &max_sz, &min_nr_a, &max_nr_a,
- &min_age, &max_age, &action, &parsed);
- if (ret != 7)
+ &min_age, &max_age, &action, &limit.sz,
+ &limit.ms, &parsed);
+ if (ret != 9)
break;
if (!damos_action_valid(action)) {
pr_err("wrong action %d\n", action);
@@ -1133,6 +1135,15 @@ static ssize_t dbgfs_monitor_on_write(struct file *file,
return ret;
}

+/*
+ * v1: Add the scheme speed limit
+ */
+static ssize_t dbgfs_version_read(struct file *file,
+ char __user *buf, size_t count, loff_t *ppos)
+{
+ return simple_read_from_buffer(buf, count, ppos, "1\n", 2);
+}
+
static const struct file_operations mk_contexts_fops = {
.owner = THIS_MODULE,
.write = dbgfs_mk_context_write,
@@ -1149,13 +1160,18 @@ static const struct file_operations monitor_on_fops = {
.write = dbgfs_monitor_on_write,
};

+static const struct file_operations version_fops = {
+ .owner = THIS_MODULE,
+ .read = dbgfs_version_read,
+};
+
static int __init __damon_dbgfs_init(void)
{
struct dentry *dbgfs_root;
const char * const file_names[] = {"mk_contexts", "rm_contexts",
- "monitor_on"};
+ "monitor_on", "version"};
const struct file_operations *fops[] = {&mk_contexts_fops,
- &rm_contexts_fops, &monitor_on_fops};
+ &rm_contexts_fops, &monitor_on_fops, &version_fops};
int i;

dbgfs_root = debugfs_create_dir("damon", NULL);
--
2.17.1