Doing DAMOS_LRU_[DE]PRIO with DAMOS_QUOTA_[IN]ACTIVE_MEM_BP based quota auto-tuning can be easy and intuitive, compared to the manual [de]prioritization target access pattern thresholds tuning. For example, users can ask DAMON to "find hot/cold pages and activate/deactivate those aiming 50:50 active:inactive memory size." But DAMON_LRU_SORT has no interface to do that. Add a module parameter for setting the target ratio. Signed-off-by: SeongJae Park --- mm/damon/lru_sort.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/mm/damon/lru_sort.c b/mm/damon/lru_sort.c index f1fdb37b9b47..f3a9dfc246b6 100644 --- a/mm/damon/lru_sort.c +++ b/mm/damon/lru_sort.c @@ -41,6 +41,20 @@ static bool enabled __read_mostly; static bool commit_inputs __read_mostly; module_param(commit_inputs, bool, 0600); +/* + * Desired active to [in]active memory ratio in bp (1/10,000). + * + * While keeping the caps that set by other quotas, DAMON_LRU_SORT + * automatically increases and decreases the effective level of the quota + * aiming the LRU [de]prioritizations of the hot and cold memory resulting in + * this active to [in]active memory ratio. Value zero means disabling this + * auto-tuning feature. + * + * Disabled by default. + */ +static unsigned long active_mem_bp __read_mostly; +module_param(active_mem_bp, ulong, 0600); + /* * Filter [non-]young pages accordingly for LRU [de]prioritizations. * @@ -208,6 +222,26 @@ static struct damos *damon_lru_sort_new_cold_scheme(unsigned int cold_thres) return damon_lru_sort_new_scheme(&pattern, DAMOS_LRU_DEPRIO); } +static int damon_lru_sort_add_quota_goals(struct damos *hot_scheme, + struct damos *cold_scheme) +{ + struct damos_quota_goal *goal; + + if (!active_mem_bp) + return 0; + goal = damos_new_quota_goal(DAMOS_QUOTA_ACTIVE_MEM_BP, active_mem_bp); + if (!goal) + return -ENOMEM; + damos_add_quota_goal(&hot_scheme->quota, goal); + /* aim 0.2 % goal conflict, to keep little ping pong */ + goal = damos_new_quota_goal(DAMOS_QUOTA_INACTIVE_MEM_BP, + 10000 - active_mem_bp + 2); + if (!goal) + return -ENOMEM; + damos_add_quota_goal(&hot_scheme->quota, goal); + return 0; +} + static int damon_lru_sort_add_filters(struct damos *hot_scheme, struct damos *cold_scheme) { @@ -277,6 +311,9 @@ static int damon_lru_sort_apply_parameters(void) damon_set_schemes(param_ctx, &hot_scheme, 1); damon_add_scheme(param_ctx, cold_scheme); + err = damon_lru_sort_add_quota_goals(hot_scheme, cold_scheme); + if (err) + goto out; err = damon_lru_sort_add_filters(hot_scheme, cold_scheme); if (err) goto out; -- 2.47.3