DAMOS allow users to specify the quota as they want in multiple ways
including time quota, size quota, and feedback-based auto-tuning. DAMOS
makes one effective quota out of the inputs and use it at the end.
Knowing the current effective quota helps understanding DAMOS' internal
mechanism and fine-tuning quotas. DAMON kernel API users can get the
information from ->esz field of damos_quota struct, but the field is
marked as private purpose, and not kernel-doc documented. Make it
public and document.
Signed-off-by: SeongJae Park <sj@xxxxxxxxxx>
---
include/linux/damon.h | 6 ++++--
mm/damon/core.c | 8 ++++----
2 files changed, 8 insertions(+), 6 deletions(-)
diff --git a/include/linux/damon.h b/include/linux/damon.h
index 5881e4ac30be..93ef45b87b9c 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -138,6 +138,7 @@ enum damos_action {
*
* @get_score: Feedback function for self-tuning quota.
* @get_score_arg: Parameter for @get_score
+ * @esz: Effective size quota in bytes.
*
* To avoid consuming too much CPU time or IO resources for applying the
* &struct damos->action to large memory, DAMON allows users to set time and/or
@@ -167,6 +168,8 @@ enum damos_action {
* tuning is getting the feedback screo value of 10,000. If @ms and/or @sz are
* set together, those work as a hard limit quota. If neither @ms nor @sz are
* set, the mechanism starts from the quota of one byte.
+ *
+ * The resulting effective size quota in bytes is set to @esz.
*/
struct damos_quota {
unsigned long ms;
@@ -179,14 +182,13 @@ struct damos_quota {
unsigned long (*get_score)(void *arg);
void *get_score_arg;
+ unsigned long esz;
/* private: */
/* For throughput estimation */
unsigned long total_charged_sz;
unsigned long total_charged_ns;
- unsigned long esz; /* Effective size quota in bytes */
-
/* For charging the quota */
unsigned long charged_sz;
unsigned long charged_from;
diff --git a/mm/damon/core.c b/mm/damon/core.c
index 5b325749fc12..0656966a6fc4 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -299,12 +299,12 @@ void damos_destroy_filter(struct damos_filter *f)
damos_free_filter(f);
}
-/* initialize private fields of damos_quota and return the pointer */
-static struct damos_quota *damos_quota_init_priv(struct damos_quota *quota)
+/* initialize fields of @quota that normally API users wouldn't set */
+static struct damos_quota *damos_quota_init(struct damos_quota *quota)
{
+ quota->esz = 0;
quota->total_charged_sz = 0;
quota->total_charged_ns = 0;
- quota->esz = 0;
quota->charged_sz = 0;
quota->charged_from = 0;
quota->charge_target_from = NULL;
@@ -336,7 +336,7 @@ struct damos *damon_new_scheme(struct damos_access_pattern *pattern,
scheme->stat = (struct damos_stat){};
INIT_LIST_HEAD(&scheme->list);
- scheme->quota = *(damos_quota_init_priv(quota));
+ scheme->quota = *(damos_quota_init(quota));
scheme->wmarks = *wmarks;
scheme->wmarks.activated = true;
--
2.39.2
