forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
459 lines
13 KiB
459 lines
13 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
/* |
|
* DAMON-based page reclamation |
|
* |
|
* Author: SeongJae Park <[email protected]> |
|
*/ |
|
|
|
#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> |
|
|
|
#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); |
|
|
|
/* |
|
* Limit of time for trying the reclamation in milliseconds. |
|
* |
|
* DAMON_RECLAIM tries to use only up to this time within a time window |
|
* (quota_reset_interval_ms) for trying reclamation of cold pages. This can be |
|
* used for limiting CPU consumption of DAMON_RECLAIM. If the value is zero, |
|
* the limit is disabled. |
|
* |
|
* 10 ms by default. |
|
*/ |
|
static unsigned long quota_ms __read_mostly = 10; |
|
module_param(quota_ms, ulong, 0600); |
|
|
|
/* |
|
* Limit of size of memory for the reclamation in bytes. |
|
* |
|
* DAMON_RECLAIM charges amount of memory which it tried to reclaim within a |
|
* time window (quota_reset_interval_ms) and makes no more than this limit is |
|
* tried. This can be used for limiting consumption of CPU and IO. If this |
|
* value is zero, the limit is disabled. |
|
* |
|
* 128 MiB by default. |
|
*/ |
|
static unsigned long quota_sz __read_mostly = 128 * 1024 * 1024; |
|
module_param(quota_sz, ulong, 0600); |
|
|
|
/* |
|
* The time/size quota charge reset interval in milliseconds. |
|
* |
|
* The charge reset interval for the quota of time (quota_ms) and size |
|
* (quota_sz). That is, DAMON_RECLAIM does not try reclamation for more than |
|
* quota_ms milliseconds or quota_sz bytes within quota_reset_interval_ms |
|
* milliseconds. |
|
* |
|
* 1 second by default. |
|
*/ |
|
static unsigned long quota_reset_interval_ms __read_mostly = 1000; |
|
module_param(quota_reset_interval_ms, ulong, 0600); |
|
|
|
/* |
|
* The watermarks check time interval in microseconds. |
|
* |
|
* Minimal time to wait before checking the watermarks, when DAMON_RECLAIM is |
|
* enabled but inactive due to its watermarks rule. 5 seconds by default. |
|
*/ |
|
static unsigned long wmarks_interval __read_mostly = 5000000; |
|
module_param(wmarks_interval, ulong, 0600); |
|
|
|
/* |
|
* Free memory rate (per thousand) for the high watermark. |
|
* |
|
* If free memory of the system in bytes per thousand bytes is higher than |
|
* this, DAMON_RECLAIM becomes inactive, so it does nothing but periodically |
|
* checks the watermarks. 500 (50%) by default. |
|
*/ |
|
static unsigned long wmarks_high __read_mostly = 500; |
|
module_param(wmarks_high, ulong, 0600); |
|
|
|
/* |
|
* Free memory rate (per thousand) for the middle watermark. |
|
* |
|
* If free memory of the system in bytes per thousand bytes is between this and |
|
* the low watermark, DAMON_RECLAIM becomes active, so starts the monitoring |
|
* and the reclaiming. 400 (40%) by default. |
|
*/ |
|
static unsigned long wmarks_mid __read_mostly = 400; |
|
module_param(wmarks_mid, ulong, 0600); |
|
|
|
/* |
|
* Free memory rate (per thousand) for the low watermark. |
|
* |
|
* If free memory of the system in bytes per thousand bytes is lower than this, |
|
* DAMON_RECLAIM becomes inactive, so it does nothing but periodically checks |
|
* the watermarks. In the case, the system falls back to the LRU-based page |
|
* granularity reclamation logic. 200 (20%) by default. |
|
*/ |
|
static unsigned long wmarks_low __read_mostly = 200; |
|
module_param(wmarks_low, ulong, 0600); |
|
|
|
/* |
|
* Sampling interval for the monitoring in microseconds. |
|
* |
|
* The sampling interval of DAMON for the cold memory monitoring. Please refer |
|
* to the DAMON documentation for more detail. 5 ms by default. |
|
*/ |
|
static unsigned long sample_interval __read_mostly = 5000; |
|
module_param(sample_interval, ulong, 0600); |
|
|
|
/* |
|
* Aggregation interval for the monitoring in microseconds. |
|
* |
|
* The aggregation interval of DAMON for the cold memory monitoring. Please |
|
* refer to the DAMON documentation for more detail. 100 ms by default. |
|
*/ |
|
static unsigned long aggr_interval __read_mostly = 100000; |
|
module_param(aggr_interval, ulong, 0600); |
|
|
|
/* |
|
* Minimum number of monitoring regions. |
|
* |
|
* The minimal number of monitoring regions of DAMON for the cold memory |
|
* monitoring. This can be used to set lower-bound of the monitoring quality. |
|
* But, setting this too high could result in increased monitoring overhead. |
|
* Please refer to the DAMON documentation for more detail. 10 by default. |
|
*/ |
|
static unsigned long min_nr_regions __read_mostly = 10; |
|
module_param(min_nr_regions, ulong, 0600); |
|
|
|
/* |
|
* Maximum number of monitoring regions. |
|
* |
|
* The maximum number of monitoring regions of DAMON for the cold memory |
|
* monitoring. This can be used to set upper-bound of the monitoring overhead. |
|
* However, setting this too low could result in bad monitoring quality. |
|
* Please refer to the DAMON documentation for more detail. 1000 by default. |
|
*/ |
|
static unsigned long max_nr_regions __read_mostly = 1000; |
|
module_param(max_nr_regions, ulong, 0600); |
|
|
|
/* |
|
* 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); |
|
|
|
/* |
|
* Number of memory regions that tried to be reclaimed. |
|
*/ |
|
static unsigned long nr_reclaim_tried_regions __read_mostly; |
|
module_param(nr_reclaim_tried_regions, ulong, 0400); |
|
|
|
/* |
|
* Total bytes of memory regions that tried to be reclaimed. |
|
*/ |
|
static unsigned long bytes_reclaim_tried_regions __read_mostly; |
|
module_param(bytes_reclaim_tried_regions, ulong, 0400); |
|
|
|
/* |
|
* Number of memory regions that successfully be reclaimed. |
|
*/ |
|
static unsigned long nr_reclaimed_regions __read_mostly; |
|
module_param(nr_reclaimed_regions, ulong, 0400); |
|
|
|
/* |
|
* Total bytes of memory regions that successfully be reclaimed. |
|
*/ |
|
static unsigned long bytes_reclaimed_regions __read_mostly; |
|
module_param(bytes_reclaimed_regions, ulong, 0400); |
|
|
|
/* |
|
* Number of times that the time/space quota limits have exceeded |
|
*/ |
|
static unsigned long nr_quota_exceeds __read_mostly; |
|
module_param(nr_quota_exceeds, ulong, 0400); |
|
|
|
static struct damon_ctx *ctx; |
|
static struct damon_target *target; |
|
|
|
struct damon_reclaim_ram_walk_arg { |
|
unsigned long start; |
|
unsigned long end; |
|
}; |
|
|
|
static int walk_system_ram(struct resource *res, void *arg) |
|
{ |
|
struct damon_reclaim_ram_walk_arg *a = arg; |
|
|
|
if (a->end - a->start < resource_size(res)) { |
|
a->start = res->start; |
|
a->end = res->end; |
|
} |
|
return 0; |
|
} |
|
|
|
/* |
|
* Find biggest 'System RAM' resource and store its start and end address in |
|
* @start and @end, respectively. If no System RAM is found, returns false. |
|
*/ |
|
static bool get_monitoring_region(unsigned long *start, unsigned long *end) |
|
{ |
|
struct damon_reclaim_ram_walk_arg arg = {}; |
|
|
|
walk_system_ram_res(0, ULONG_MAX, &arg, walk_system_ram); |
|
if (arg.end <= arg.start) |
|
return false; |
|
|
|
*start = arg.start; |
|
*end = arg.end; |
|
return true; |
|
} |
|
|
|
static struct damos *damon_reclaim_new_scheme(void) |
|
{ |
|
struct damos_watermarks wmarks = { |
|
.metric = DAMOS_WMARK_FREE_MEM_RATE, |
|
.interval = wmarks_interval, |
|
.high = wmarks_high, |
|
.mid = wmarks_mid, |
|
.low = wmarks_low, |
|
}; |
|
struct damos_quota quota = { |
|
/* |
|
* Do not try reclamation for more than quota_ms milliseconds |
|
* or quota_sz bytes within quota_reset_interval_ms. |
|
*/ |
|
.ms = quota_ms, |
|
.sz = quota_sz, |
|
.reset_interval = quota_reset_interval_ms, |
|
/* Within the quota, page out older regions first. */ |
|
.weight_sz = 0, |
|
.weight_nr_accesses = 0, |
|
.weight_age = 1 |
|
}; |
|
struct damos *scheme = damon_new_scheme( |
|
/* Find regions having PAGE_SIZE or larger size */ |
|
PAGE_SIZE, ULONG_MAX, |
|
/* and not accessed at all */ |
|
0, 0, |
|
/* for min_age or more micro-seconds, and */ |
|
min_age / aggr_interval, UINT_MAX, |
|
/* page out those, as soon as found */ |
|
DAMOS_PAGEOUT, |
|
/* under the quota. */ |
|
"a, |
|
/* (De)activate this according to the watermarks. */ |
|
&wmarks); |
|
|
|
return scheme; |
|
} |
|
|
|
static int damon_reclaim_apply_parameters(void) |
|
{ |
|
struct damos *scheme; |
|
struct damon_addr_range addr_range; |
|
int err = 0; |
|
|
|
err = damon_set_attrs(ctx, sample_interval, aggr_interval, 0, |
|
min_nr_regions, max_nr_regions); |
|
if (err) |
|
return err; |
|
|
|
/* Will be freed by next 'damon_set_schemes()' below */ |
|
scheme = damon_reclaim_new_scheme(); |
|
if (!scheme) |
|
return -ENOMEM; |
|
err = damon_set_schemes(ctx, &scheme, 1); |
|
if (err) |
|
return err; |
|
|
|
if (monitor_region_start > monitor_region_end) |
|
return -EINVAL; |
|
if (!monitor_region_start && !monitor_region_end && |
|
!get_monitoring_region(&monitor_region_start, |
|
&monitor_region_end)) |
|
return -EINVAL; |
|
addr_range.start = monitor_region_start; |
|
addr_range.end = monitor_region_end; |
|
return damon_set_regions(target, &addr_range, 1); |
|
} |
|
|
|
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) { |
|
nr_reclaim_tried_regions = s->stat.nr_tried; |
|
bytes_reclaim_tried_regions = s->stat.sz_tried; |
|
nr_reclaimed_regions = s->stat.nr_applied; |
|
bytes_reclaimed_regions = s->stat.sz_applied; |
|
nr_quota_exceeds = s->stat.qt_exceeds; |
|
} |
|
|
|
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);
|
|
|