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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /mm/damon/reclaim.c | |
parent | Initial commit. (diff) | |
download | linux-upstream/6.1.76.tar.xz linux-upstream/6.1.76.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'mm/damon/reclaim.c')
-rw-r--r-- | mm/damon/reclaim.c | 284 |
1 files changed, 284 insertions, 0 deletions
diff --git a/mm/damon/reclaim.c b/mm/damon/reclaim.c new file mode 100644 index 000000000..162c9b1ca --- /dev/null +++ b/mm/damon/reclaim.c @@ -0,0 +1,284 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * DAMON-based page reclamation + * + * Author: SeongJae Park <sj@kernel.org> + */ + +#define pr_fmt(fmt) "damon-reclaim: " fmt + +#include <linux/damon.h> +#include <linux/ioport.h> +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/workqueue.h> + +#include "modules-common.h" + +#ifdef MODULE_PARAM_PREFIX +#undef MODULE_PARAM_PREFIX +#endif +#define MODULE_PARAM_PREFIX "damon_reclaim." + +/* + * Enable or disable DAMON_RECLAIM. + * + * You can enable DAMON_RCLAIM by setting the value of this parameter as ``Y``. + * Setting it as ``N`` disables DAMON_RECLAIM. Note that DAMON_RECLAIM could + * do no real monitoring and reclamation due to the watermarks-based activation + * condition. Refer to below descriptions for the watermarks parameter for + * this. + */ +static bool enabled __read_mostly; + +/* + * Make DAMON_RECLAIM reads the input parameters again, except ``enabled``. + * + * Input parameters that updated while DAMON_RECLAIM is running are not applied + * by default. Once this parameter is set as ``Y``, DAMON_RECLAIM reads values + * of parametrs except ``enabled`` again. Once the re-reading is done, this + * parameter is set as ``N``. If invalid parameters are found while the + * re-reading, DAMON_RECLAIM will be disabled. + */ +static bool commit_inputs __read_mostly; +module_param(commit_inputs, bool, 0600); + +/* + * Time threshold for cold memory regions identification in microseconds. + * + * If a memory region is not accessed for this or longer time, DAMON_RECLAIM + * identifies the region as cold, and reclaims. 120 seconds by default. + */ +static unsigned long min_age __read_mostly = 120000000; +module_param(min_age, ulong, 0600); + +static struct damos_quota damon_reclaim_quota = { + /* use up to 10 ms time, reclaim up to 128 MiB per 1 sec by default */ + .ms = 10, + .sz = 128 * 1024 * 1024, + .reset_interval = 1000, + /* Within the quota, page out older regions first. */ + .weight_sz = 0, + .weight_nr_accesses = 0, + .weight_age = 1 +}; +DEFINE_DAMON_MODULES_DAMOS_QUOTAS(damon_reclaim_quota); + +static struct damos_watermarks damon_reclaim_wmarks = { + .metric = DAMOS_WMARK_FREE_MEM_RATE, + .interval = 5000000, /* 5 seconds */ + .high = 500, /* 50 percent */ + .mid = 400, /* 40 percent */ + .low = 200, /* 20 percent */ +}; +DEFINE_DAMON_MODULES_WMARKS_PARAMS(damon_reclaim_wmarks); + +static struct damon_attrs damon_reclaim_mon_attrs = { + .sample_interval = 5000, /* 5 ms */ + .aggr_interval = 100000, /* 100 ms */ + .ops_update_interval = 0, + .min_nr_regions = 10, + .max_nr_regions = 1000, +}; +DEFINE_DAMON_MODULES_MON_ATTRS_PARAMS(damon_reclaim_mon_attrs); + +/* + * Start of the target memory region in physical address. + * + * The start physical address of memory region that DAMON_RECLAIM will do work + * against. By default, biggest System RAM is used as the region. + */ +static unsigned long monitor_region_start __read_mostly; +module_param(monitor_region_start, ulong, 0600); + +/* + * End of the target memory region in physical address. + * + * The end physical address of memory region that DAMON_RECLAIM will do work + * against. By default, biggest System RAM is used as the region. + */ +static unsigned long monitor_region_end __read_mostly; +module_param(monitor_region_end, ulong, 0600); + +/* + * PID of the DAMON thread + * + * If DAMON_RECLAIM is enabled, this becomes the PID of the worker thread. + * Else, -1. + */ +static int kdamond_pid __read_mostly = -1; +module_param(kdamond_pid, int, 0400); + +static struct damos_stat damon_reclaim_stat; +DEFINE_DAMON_MODULES_DAMOS_STATS_PARAMS(damon_reclaim_stat, + reclaim_tried_regions, reclaimed_regions, quota_exceeds); + +static struct damon_ctx *ctx; +static struct damon_target *target; + +static struct damos *damon_reclaim_new_scheme(void) +{ + struct damos_access_pattern pattern = { + /* Find regions having PAGE_SIZE or larger size */ + .min_sz_region = PAGE_SIZE, + .max_sz_region = ULONG_MAX, + /* and not accessed at all */ + .min_nr_accesses = 0, + .max_nr_accesses = 0, + /* for min_age or more micro-seconds */ + .min_age_region = min_age / + damon_reclaim_mon_attrs.aggr_interval, + .max_age_region = UINT_MAX, + }; + + return damon_new_scheme( + &pattern, + /* page out those, as soon as found */ + DAMOS_PAGEOUT, + /* under the quota. */ + &damon_reclaim_quota, + /* (De)activate this according to the watermarks. */ + &damon_reclaim_wmarks); +} + +static int damon_reclaim_apply_parameters(void) +{ + struct damos *scheme; + int err = 0; + + err = damon_set_attrs(ctx, &damon_reclaim_mon_attrs); + if (err) + return err; + + /* Will be freed by next 'damon_set_schemes()' below */ + scheme = damon_reclaim_new_scheme(); + if (!scheme) + return -ENOMEM; + damon_set_schemes(ctx, &scheme, 1); + + return damon_set_region_biggest_system_ram_default(target, + &monitor_region_start, + &monitor_region_end); +} + +static int damon_reclaim_turn(bool on) +{ + int err; + + if (!on) { + err = damon_stop(&ctx, 1); + if (!err) + kdamond_pid = -1; + return err; + } + + err = damon_reclaim_apply_parameters(); + if (err) + return err; + + err = damon_start(&ctx, 1, true); + if (err) + return err; + kdamond_pid = ctx->kdamond->pid; + return 0; +} + +static struct delayed_work damon_reclaim_timer; +static void damon_reclaim_timer_fn(struct work_struct *work) +{ + static bool last_enabled; + bool now_enabled; + + now_enabled = enabled; + if (last_enabled != now_enabled) { + if (!damon_reclaim_turn(now_enabled)) + last_enabled = now_enabled; + else + enabled = last_enabled; + } +} +static DECLARE_DELAYED_WORK(damon_reclaim_timer, damon_reclaim_timer_fn); + +static bool damon_reclaim_initialized; + +static int damon_reclaim_enabled_store(const char *val, + const struct kernel_param *kp) +{ + int rc = param_set_bool(val, kp); + + if (rc < 0) + return rc; + + /* system_wq might not initialized yet */ + if (!damon_reclaim_initialized) + return rc; + + schedule_delayed_work(&damon_reclaim_timer, 0); + return 0; +} + +static const struct kernel_param_ops enabled_param_ops = { + .set = damon_reclaim_enabled_store, + .get = param_get_bool, +}; + +module_param_cb(enabled, &enabled_param_ops, &enabled, 0600); +MODULE_PARM_DESC(enabled, + "Enable or disable DAMON_RECLAIM (default: disabled)"); + +static int damon_reclaim_handle_commit_inputs(void) +{ + int err; + + if (!commit_inputs) + return 0; + + err = damon_reclaim_apply_parameters(); + commit_inputs = false; + return err; +} + +static int damon_reclaim_after_aggregation(struct damon_ctx *c) +{ + struct damos *s; + + /* update the stats parameter */ + damon_for_each_scheme(s, c) + damon_reclaim_stat = s->stat; + + return damon_reclaim_handle_commit_inputs(); +} + +static int damon_reclaim_after_wmarks_check(struct damon_ctx *c) +{ + return damon_reclaim_handle_commit_inputs(); +} + +static int __init damon_reclaim_init(void) +{ + ctx = damon_new_ctx(); + if (!ctx) + return -ENOMEM; + + if (damon_select_ops(ctx, DAMON_OPS_PADDR)) { + damon_destroy_ctx(ctx); + return -EINVAL; + } + + ctx->callback.after_wmarks_check = damon_reclaim_after_wmarks_check; + ctx->callback.after_aggregation = damon_reclaim_after_aggregation; + + target = damon_new_target(); + if (!target) { + damon_destroy_ctx(ctx); + return -ENOMEM; + } + damon_add_target(ctx, target); + + schedule_delayed_work(&damon_reclaim_timer, 0); + + damon_reclaim_initialized = true; + return 0; +} + +module_init(damon_reclaim_init); |