From 106e26fc1c4c1a0e3747246e15df2bc3aa9d46b2 Mon Sep 17 00:00:00 2001 From: SeongJae Park Date: Mon, 19 Feb 2024 11:44:18 -0800 Subject: [PATCH] mm/damon/core: split out quota goal related fields to a struct 'struct damos_quota' is not small now. Split out fields for quota goal to a separate struct for easier reading. Link: https://lkml.kernel.org/r/20240219194431.159606-8-sj@kernel.org Signed-off-by: SeongJae Park Signed-off-by: Andrew Morton --- include/linux/damon.h | 36 ++++++++++++++++++++++-------------- mm/damon/core.c | 13 +++++++------ mm/damon/sysfs-schemes.c | 10 +++++----- 3 files changed, 34 insertions(+), 25 deletions(-) diff --git a/include/linux/damon.h b/include/linux/damon.h index bd17b14828bc..2fe345adf6b2 100644 --- a/include/linux/damon.h +++ b/include/linux/damon.h @@ -126,13 +126,28 @@ enum damos_action { NR_DAMOS_ACTIONS, }; +/** + * struct damos_quota_goal - DAMOS scheme quota auto-tuning goal. + * @get_score: Function for getting current score of the goal. + * @get_score_arg: Parameter for @get_score + * + * Data structure for getting the current score of the quota tuning goal. + * Calling @get_score with @get_score_arg as the parameter should return the + * current score. Then the score is entered to DAMON's internal feedback loop + * mechanism to get the auto-tuned quota. The goal of the tuning is getting + * the feedback score value of 10,000. + */ +struct damos_quota_goal { + unsigned long (*get_score)(void *arg); + void *get_score_arg; +}; + /** * struct damos_quota - Controls the aggressiveness of the given scheme. * @reset_interval: Charge reset interval in milliseconds. * @ms: Maximum milliseconds that the scheme can use. * @sz: Maximum bytes of memory that the action can be applied. - * @get_score: Feedback function for self-tuning quota. - * @get_score_arg: Parameter for @get_score + * @goal: Quota auto-tuning goal. * @esz: Effective size quota in bytes. * * @weight_sz: Weight of the region's size for prioritization. @@ -151,16 +166,10 @@ enum damos_action { * throughput of the scheme's action. DAMON then compares it against &sz and * uses smaller one as the effective quota. * - * If @get_score function pointer is set, DAMON calls it back with - * @get_score_arg and get the return value of it for every @reset_interval. - * Then, DAMON adjusts the effective quota using the return value as a feedback - * score to the current quota, using its internal feedback loop algorithm. - * - * The feedback loop algorithem assumes the quota input and the feedback score - * output are in a positive proportional relationship, and the goal of the - * 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. + * If ->get_score field of @goal is set, DAMON calculates yet another size + * quota based on the goal 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. * * The resulting effective size quota in bytes is set to @esz. * @@ -174,8 +183,7 @@ struct damos_quota { unsigned long reset_interval; unsigned long ms; unsigned long sz; - unsigned long (*get_score)(void *arg); - void *get_score_arg; + struct damos_quota_goal goal; unsigned long esz; unsigned int weight_sz; diff --git a/mm/damon/core.c b/mm/damon/core.c index 0656966a6fc4..fe4209672121 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -1083,21 +1083,22 @@ static unsigned long damon_feed_loop_next_input(unsigned long last_input, return min_input; } -/* Shouldn't be called if quota->ms, quota->sz, and quota->get_score unset */ +/* Called only if quota->ms, quota->sz, or quota->goal.get_score are set */ static void damos_set_effective_quota(struct damos_quota *quota) { unsigned long throughput; unsigned long esz; - if (!quota->ms && !quota->get_score) { + if (!quota->ms && !quota->goal.get_score) { quota->esz = quota->sz; return; } - if (quota->get_score) { + if (quota->goal.get_score) { quota->esz_bp = damon_feed_loop_next_input( max(quota->esz_bp, 10000UL), - quota->get_score(quota->get_score_arg)); + quota->goal.get_score( + quota->goal.get_score_arg)); esz = quota->esz_bp / 10000; } @@ -1107,7 +1108,7 @@ static void damos_set_effective_quota(struct damos_quota *quota) quota->total_charged_ns; else throughput = PAGE_SIZE * 1024; - if (quota->get_score) + if (quota->goal.get_score) esz = min(throughput * quota->ms, esz); else esz = throughput * quota->ms; @@ -1127,7 +1128,7 @@ static void damos_adjust_quota(struct damon_ctx *c, struct damos *s) unsigned long cumulated_sz; unsigned int score, max_score = 0; - if (!quota->ms && !quota->sz && !quota->get_score) + if (!quota->ms && !quota->sz && !quota->goal.get_score) return; /* New charge window starts */ diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c index 9d90e7b757b7..85ef58f98a87 100644 --- a/mm/damon/sysfs-schemes.c +++ b/mm/damon/sysfs-schemes.c @@ -1894,19 +1894,19 @@ static void damos_sysfs_set_quota_score( struct damos_sysfs_quota_goal *sysfs_goal; int i; - quota->get_score = NULL; - quota->get_score_arg = (void *)0; + quota->goal.get_score = NULL; + quota->goal.get_score_arg = (void *)0; for (i = 0; i < sysfs_goals->nr; i++) { sysfs_goal = sysfs_goals->goals_arr[i]; if (!sysfs_goal->target_value) continue; /* Higher score makes scheme less aggressive */ - quota->get_score_arg = (void *)max( - (unsigned long)quota->get_score_arg, + quota->goal.get_score_arg = (void *)max( + (unsigned long)quota->goal.get_score_arg, sysfs_goal->current_value * 10000 / sysfs_goal->target_value); - quota->get_score = damos_sysfs_get_quota_score; + quota->goal.get_score = damos_sysfs_get_quota_score; } }