diff options
Diffstat (limited to 'include/linux/damon.h')
| -rw-r--r-- | include/linux/damon.h | 74 |
1 files changed, 60 insertions, 14 deletions
diff --git a/include/linux/damon.h b/include/linux/damon.h index ae2664d1d5f1..ab2f17d9926b 100644 --- a/include/linux/damon.h +++ b/include/linux/damon.h @@ -40,9 +40,24 @@ struct damon_addr_range { * @ar: The address range of the region. * @sampling_addr: Address of the sample for the next access check. * @nr_accesses: Access frequency of this region. + * @nr_accesses_bp: @nr_accesses in basis point (0.01%) that updated for + * each sampling interval. * @list: List head for siblings. * @age: Age of this region. * + * @nr_accesses is reset to zero for every &damon_attrs->aggr_interval and be + * increased for every &damon_attrs->sample_interval if an access to the region + * during the last sampling interval is found. The update of this field should + * not be done with direct access but with the helper function, + * damon_update_region_access_rate(). + * + * @nr_accesses_bp is another representation of @nr_accesses in basis point + * (1 in 10,000) that updated for every &damon_attrs->sample_interval in a + * manner similar to moving sum. By the algorithm, this value becomes + * @nr_accesses * 10000 for every &struct damon_attrs->aggr_interval. This can + * be used when the aggregation interval is too huge and therefore cannot wait + * for it before getting the access monitoring results. + * * @age is initially zero, increased for each aggregation interval, and reset * to zero again if the access frequency is significantly changed. If two * regions are merged into a new region, both @nr_accesses and @age of the new @@ -52,6 +67,7 @@ struct damon_region { struct damon_addr_range ar; unsigned long sampling_addr; unsigned int nr_accesses; + unsigned int nr_accesses_bp; struct list_head list; unsigned int age; @@ -298,24 +314,24 @@ struct damos_access_pattern { * struct damos - Represents a Data Access Monitoring-based Operation Scheme. * @pattern: Access pattern of target regions. * @action: &damo_action to be applied to the target regions. + * @apply_interval_us: The time between applying the @action. * @quota: Control the aggressiveness of this scheme. * @wmarks: Watermarks for automated (in)activation of this scheme. * @filters: Additional set of &struct damos_filter for &action. * @stat: Statistics of this scheme. * @list: List head for siblings. * - * For each aggregation interval, DAMON finds regions which fit in the + * For each @apply_interval_us, DAMON finds regions which fit in the * &pattern and applies &action to those. To avoid consuming too much * CPU time or IO resources for the &action, "a is used. * + * If @apply_interval_us is zero, &damon_attrs->aggr_interval is used instead. + * * To do the work only when needed, schemes can be activated for specific * system situations using &wmarks. If all schemes that registered to the * monitoring context are inactive, DAMON stops monitoring either, and just * repeatedly checks the watermarks. * - * If all schemes that registered to a &struct damon_ctx are inactive, DAMON - * stops monitoring and just repeatedly checks the watermarks. - * * Before applying the &action to a memory region, &struct damon_operations * implementation could check pages of the region and skip &action to respect * &filters @@ -327,6 +343,14 @@ struct damos_access_pattern { struct damos { struct damos_access_pattern pattern; enum damos_action action; + unsigned long apply_interval_us; +/* private: internal use only */ + /* + * number of sample intervals that should be passed before applying + * @action + */ + unsigned long next_apply_sis; +/* public: */ struct damos_quota quota; struct damos_watermarks wmarks; struct list_head filters; @@ -472,13 +496,14 @@ struct damon_callback { * regions. * * For each @sample_interval, DAMON checks whether each region is accessed or - * not. It aggregates and keeps the access information (number of accesses to - * each region) for @aggr_interval time. DAMON also checks whether the target - * memory regions need update (e.g., by ``mmap()`` calls from the application, - * in case of virtual memory monitoring) and applies the changes for each - * @ops_update_interval. All time intervals are in micro-seconds. - * Please refer to &struct damon_operations and &struct damon_callback for more - * detail. + * not during the last @sample_interval. If such access is found, DAMON + * aggregates the information by increasing &damon_region->nr_accesses for + * @aggr_interval time. For each @aggr_interval, the count is reset. DAMON + * also checks whether the target memory regions need update (e.g., by + * ``mmap()`` calls from the application, in case of virtual memory monitoring) + * and applies the changes for each @ops_update_interval. All time intervals + * are in micro-seconds. Please refer to &struct damon_operations and &struct + * damon_callback for more detail. */ struct damon_attrs { unsigned long sample_interval; @@ -522,8 +547,18 @@ struct damon_ctx { struct damon_attrs attrs; /* private: internal use only */ - struct timespec64 last_aggregation; - struct timespec64 last_ops_update; + /* number of sample intervals that passed since this context started */ + unsigned long passed_sample_intervals; + /* + * number of sample intervals that should be passed before next + * aggregation + */ + unsigned long next_aggregation_sis; + /* + * number of sample intervals that should be passed before next ops + * update + */ + unsigned long next_ops_update_sis; /* public: */ struct task_struct *kdamond; @@ -608,6 +643,8 @@ void damon_add_region(struct damon_region *r, struct damon_target *t); void damon_destroy_region(struct damon_region *r, struct damon_target *t); int damon_set_regions(struct damon_target *t, struct damon_addr_range *ranges, unsigned int nr_ranges); +void damon_update_region_access_rate(struct damon_region *r, bool accessed, + struct damon_attrs *attrs); struct damos_filter *damos_new_filter(enum damos_filter_type type, bool matching); @@ -615,7 +652,9 @@ void damos_add_filter(struct damos *s, struct damos_filter *f); void damos_destroy_filter(struct damos_filter *f); struct damos *damon_new_scheme(struct damos_access_pattern *pattern, - enum damos_action action, struct damos_quota *quota, + enum damos_action action, + unsigned long apply_interval_us, + struct damos_quota *quota, struct damos_watermarks *wmarks); void damon_add_scheme(struct damon_ctx *ctx, struct damos *s); void damon_destroy_scheme(struct damos *s); @@ -642,6 +681,13 @@ static inline bool damon_target_has_pid(const struct damon_ctx *ctx) return ctx->ops.id == DAMON_OPS_VADDR || ctx->ops.id == DAMON_OPS_FVADDR; } +static inline unsigned int damon_max_nr_accesses(const struct damon_attrs *attrs) +{ + /* {aggr,sample}_interval are unsigned long, hence could overflow */ + return min(attrs->aggr_interval / attrs->sample_interval, + (unsigned long)UINT_MAX); +} + int damon_start(struct damon_ctx **ctxs, int nr_ctxs, bool exclusive); int damon_stop(struct damon_ctx **ctxs, int nr_ctxs); |