mm/damon: explain "effective quota" on kernel-doc comment

The kernel-doc comment for 'struct damos_quota' describes how "effective
quota" is calculated, but does not explain what it is.  Actually there was
an input[1] about it.  Add the explanation on the comment.

Also, fix a trivial typo on the comment block: s/empt/empty/

[1] https://github.com/damonitor/damo/issues/17#issuecomment-2497525043

Link: https://lkml.kernel.org/r/20250110185232.54907-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Suggested-by: Honggyu Kim <honggyu.kim@sk.com>
Cc: Yunjeong Mun <yunjeong.mun@sk.com>
Cc: Honggyu Kim <honggyu.kim@sk.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/damon.h b/include/linux/damon.h
index 0834d7ffcb84bd1c8309d71f27bf70942b69b2b5..af525252b853a1e7661098a8d41ad1f921b10989 100644 (file)
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -193,11 +193,16 @@ struct damos_quota_goal {
  * size quota is set, DAMON tries to apply the action only up to &sz bytes
  * within &reset_interval.
  *
- * Internally, the time quota is transformed to a size quota using estimated
- * throughput of the scheme's action.  DAMON then compares it against &sz and
- * uses smaller one as the effective quota.
+ * To convince the different types of quotas and goals, DAMON internally
+ * converts those into one single size quota called "effective quota".  DAMON
+ * internally uses it as the only one real quota.  The conversion is made as
+ * follows.
  *
- * If @goals is not empt, DAMON calculates yet another size quota based on the
+ * The time quota is transformed to a size quota using estimated throughput of
+ * the scheme's action.  DAMON then compares it against &sz and uses smaller
+ * one as the effective quota.
+ *
+ * If @goals is not empty, DAMON calculates yet another size quota based on the
  * goals using its internal feedback loop algorithm, for every @reset_interval.
  * Then, if the new size quota is smaller than the effective quota, it uses the
  * new size quota as the effective quota.