25e8acbcf1
The aggregation interval of test purpose damon_attrs for
damon_test_nr_accesses_to_accesses_bp() becomes zero on 32 bit
architecture, since size of int and long types are same. As a result,
damon_nr_accesses_to_accesses_bp() call with the test data triggers
divide-by-zero exception. damon_nr_accesses_to_accesses_bp() shouldn't
be called with such data, and the non-test code avoids that by checking
the case on damon_update_monitoring_results(). Skip the test code in
the case, and add an explicit caution of the case on the comment for the
test target function.
Link: https://lkml.kernel.org/r/20240905162423.74053-1-sj@kernel.org
Fixes: 5e06ad5900
("mm/damon/core-test: test max_nr_accesses overflow caused divide-by-zero")
Signed-off-by: SeongJae Park <sj@kernel.org>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Closes: https://lore.kernel.org/c771b962-a58f-435b-89e4-1211a9323181@roeck-us.net
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Gow <davidgow@google.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2223 lines
57 KiB
C
2223 lines
57 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Data Access Monitor
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*
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* Author: SeongJae Park <sj@kernel.org>
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*/
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#define pr_fmt(fmt) "damon: " fmt
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#include <linux/damon.h>
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#include <linux/delay.h>
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#include <linux/kthread.h>
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#include <linux/mm.h>
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#include <linux/psi.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#define CREATE_TRACE_POINTS
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#include <trace/events/damon.h>
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#ifdef CONFIG_DAMON_KUNIT_TEST
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#undef DAMON_MIN_REGION
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#define DAMON_MIN_REGION 1
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#endif
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static DEFINE_MUTEX(damon_lock);
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static int nr_running_ctxs;
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static bool running_exclusive_ctxs;
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static DEFINE_MUTEX(damon_ops_lock);
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static struct damon_operations damon_registered_ops[NR_DAMON_OPS];
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static struct kmem_cache *damon_region_cache __ro_after_init;
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/* Should be called under damon_ops_lock with id smaller than NR_DAMON_OPS */
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static bool __damon_is_registered_ops(enum damon_ops_id id)
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{
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struct damon_operations empty_ops = {};
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if (!memcmp(&empty_ops, &damon_registered_ops[id], sizeof(empty_ops)))
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return false;
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return true;
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}
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/**
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* damon_is_registered_ops() - Check if a given damon_operations is registered.
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* @id: Id of the damon_operations to check if registered.
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*
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* Return: true if the ops is set, false otherwise.
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*/
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bool damon_is_registered_ops(enum damon_ops_id id)
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{
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bool registered;
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if (id >= NR_DAMON_OPS)
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return false;
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mutex_lock(&damon_ops_lock);
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registered = __damon_is_registered_ops(id);
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mutex_unlock(&damon_ops_lock);
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return registered;
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}
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/**
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* damon_register_ops() - Register a monitoring operations set to DAMON.
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* @ops: monitoring operations set to register.
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*
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* This function registers a monitoring operations set of valid &struct
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* damon_operations->id so that others can find and use them later.
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*
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* Return: 0 on success, negative error code otherwise.
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*/
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int damon_register_ops(struct damon_operations *ops)
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{
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int err = 0;
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if (ops->id >= NR_DAMON_OPS)
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return -EINVAL;
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mutex_lock(&damon_ops_lock);
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/* Fail for already registered ops */
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if (__damon_is_registered_ops(ops->id)) {
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err = -EINVAL;
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goto out;
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}
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damon_registered_ops[ops->id] = *ops;
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out:
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mutex_unlock(&damon_ops_lock);
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return err;
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}
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/**
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* damon_select_ops() - Select a monitoring operations to use with the context.
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* @ctx: monitoring context to use the operations.
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* @id: id of the registered monitoring operations to select.
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*
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* This function finds registered monitoring operations set of @id and make
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* @ctx to use it.
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*
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* Return: 0 on success, negative error code otherwise.
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*/
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int damon_select_ops(struct damon_ctx *ctx, enum damon_ops_id id)
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{
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int err = 0;
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if (id >= NR_DAMON_OPS)
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return -EINVAL;
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mutex_lock(&damon_ops_lock);
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if (!__damon_is_registered_ops(id))
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err = -EINVAL;
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else
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ctx->ops = damon_registered_ops[id];
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mutex_unlock(&damon_ops_lock);
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return err;
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}
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/*
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* Construct a damon_region struct
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*
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* Returns the pointer to the new struct if success, or NULL otherwise
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*/
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struct damon_region *damon_new_region(unsigned long start, unsigned long end)
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{
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struct damon_region *region;
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region = kmem_cache_alloc(damon_region_cache, GFP_KERNEL);
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if (!region)
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return NULL;
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region->ar.start = start;
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region->ar.end = end;
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region->nr_accesses = 0;
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region->nr_accesses_bp = 0;
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INIT_LIST_HEAD(®ion->list);
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region->age = 0;
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region->last_nr_accesses = 0;
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return region;
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}
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void damon_add_region(struct damon_region *r, struct damon_target *t)
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{
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list_add_tail(&r->list, &t->regions_list);
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t->nr_regions++;
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}
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static void damon_del_region(struct damon_region *r, struct damon_target *t)
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{
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list_del(&r->list);
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t->nr_regions--;
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}
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static void damon_free_region(struct damon_region *r)
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{
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kmem_cache_free(damon_region_cache, r);
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}
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void damon_destroy_region(struct damon_region *r, struct damon_target *t)
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{
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damon_del_region(r, t);
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damon_free_region(r);
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}
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/*
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* Check whether a region is intersecting an address range
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*
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* Returns true if it is.
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*/
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static bool damon_intersect(struct damon_region *r,
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struct damon_addr_range *re)
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{
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return !(r->ar.end <= re->start || re->end <= r->ar.start);
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}
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/*
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* Fill holes in regions with new regions.
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*/
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static int damon_fill_regions_holes(struct damon_region *first,
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struct damon_region *last, struct damon_target *t)
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{
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struct damon_region *r = first;
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damon_for_each_region_from(r, t) {
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struct damon_region *next, *newr;
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if (r == last)
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break;
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next = damon_next_region(r);
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if (r->ar.end != next->ar.start) {
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newr = damon_new_region(r->ar.end, next->ar.start);
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if (!newr)
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return -ENOMEM;
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damon_insert_region(newr, r, next, t);
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}
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}
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return 0;
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}
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/*
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* damon_set_regions() - Set regions of a target for given address ranges.
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* @t: the given target.
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* @ranges: array of new monitoring target ranges.
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* @nr_ranges: length of @ranges.
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*
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* This function adds new regions to, or modify existing regions of a
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* monitoring target to fit in specific ranges.
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*
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* Return: 0 if success, or negative error code otherwise.
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*/
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int damon_set_regions(struct damon_target *t, struct damon_addr_range *ranges,
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unsigned int nr_ranges)
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{
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struct damon_region *r, *next;
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unsigned int i;
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int err;
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/* Remove regions which are not in the new ranges */
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damon_for_each_region_safe(r, next, t) {
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for (i = 0; i < nr_ranges; i++) {
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if (damon_intersect(r, &ranges[i]))
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break;
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}
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if (i == nr_ranges)
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damon_destroy_region(r, t);
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}
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r = damon_first_region(t);
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/* Add new regions or resize existing regions to fit in the ranges */
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for (i = 0; i < nr_ranges; i++) {
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struct damon_region *first = NULL, *last, *newr;
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struct damon_addr_range *range;
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range = &ranges[i];
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/* Get the first/last regions intersecting with the range */
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damon_for_each_region_from(r, t) {
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if (damon_intersect(r, range)) {
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if (!first)
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first = r;
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last = r;
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}
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if (r->ar.start >= range->end)
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break;
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}
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if (!first) {
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/* no region intersects with this range */
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newr = damon_new_region(
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ALIGN_DOWN(range->start,
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DAMON_MIN_REGION),
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ALIGN(range->end, DAMON_MIN_REGION));
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if (!newr)
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return -ENOMEM;
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damon_insert_region(newr, damon_prev_region(r), r, t);
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} else {
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/* resize intersecting regions to fit in this range */
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first->ar.start = ALIGN_DOWN(range->start,
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DAMON_MIN_REGION);
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last->ar.end = ALIGN(range->end, DAMON_MIN_REGION);
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/* fill possible holes in the range */
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err = damon_fill_regions_holes(first, last, t);
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if (err)
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return err;
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}
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}
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return 0;
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}
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struct damos_filter *damos_new_filter(enum damos_filter_type type,
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bool matching)
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{
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struct damos_filter *filter;
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filter = kmalloc(sizeof(*filter), GFP_KERNEL);
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if (!filter)
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return NULL;
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filter->type = type;
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filter->matching = matching;
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INIT_LIST_HEAD(&filter->list);
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return filter;
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}
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void damos_add_filter(struct damos *s, struct damos_filter *f)
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{
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list_add_tail(&f->list, &s->filters);
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}
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static void damos_del_filter(struct damos_filter *f)
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{
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list_del(&f->list);
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}
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static void damos_free_filter(struct damos_filter *f)
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{
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kfree(f);
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}
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void damos_destroy_filter(struct damos_filter *f)
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{
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damos_del_filter(f);
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damos_free_filter(f);
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}
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struct damos_quota_goal *damos_new_quota_goal(
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enum damos_quota_goal_metric metric,
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unsigned long target_value)
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{
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struct damos_quota_goal *goal;
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goal = kmalloc(sizeof(*goal), GFP_KERNEL);
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if (!goal)
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return NULL;
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goal->metric = metric;
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goal->target_value = target_value;
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INIT_LIST_HEAD(&goal->list);
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return goal;
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}
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void damos_add_quota_goal(struct damos_quota *q, struct damos_quota_goal *g)
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{
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list_add_tail(&g->list, &q->goals);
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}
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static void damos_del_quota_goal(struct damos_quota_goal *g)
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{
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list_del(&g->list);
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}
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static void damos_free_quota_goal(struct damos_quota_goal *g)
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{
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kfree(g);
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}
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void damos_destroy_quota_goal(struct damos_quota_goal *g)
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{
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damos_del_quota_goal(g);
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damos_free_quota_goal(g);
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}
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/* initialize fields of @quota that normally API users wouldn't set */
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static struct damos_quota *damos_quota_init(struct damos_quota *quota)
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{
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quota->esz = 0;
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quota->total_charged_sz = 0;
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quota->total_charged_ns = 0;
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quota->charged_sz = 0;
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quota->charged_from = 0;
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quota->charge_target_from = NULL;
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quota->charge_addr_from = 0;
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quota->esz_bp = 0;
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return quota;
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}
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struct damos *damon_new_scheme(struct damos_access_pattern *pattern,
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enum damos_action action,
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unsigned long apply_interval_us,
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struct damos_quota *quota,
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struct damos_watermarks *wmarks,
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int target_nid)
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{
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struct damos *scheme;
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scheme = kmalloc(sizeof(*scheme), GFP_KERNEL);
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if (!scheme)
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return NULL;
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scheme->pattern = *pattern;
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scheme->action = action;
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scheme->apply_interval_us = apply_interval_us;
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/*
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* next_apply_sis will be set when kdamond starts. While kdamond is
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* running, it will also updated when it is added to the DAMON context,
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* or damon_attrs are updated.
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*/
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scheme->next_apply_sis = 0;
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INIT_LIST_HEAD(&scheme->filters);
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scheme->stat = (struct damos_stat){};
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INIT_LIST_HEAD(&scheme->list);
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scheme->quota = *(damos_quota_init(quota));
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/* quota.goals should be separately set by caller */
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INIT_LIST_HEAD(&scheme->quota.goals);
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scheme->wmarks = *wmarks;
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scheme->wmarks.activated = true;
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scheme->target_nid = target_nid;
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return scheme;
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}
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static void damos_set_next_apply_sis(struct damos *s, struct damon_ctx *ctx)
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{
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unsigned long sample_interval = ctx->attrs.sample_interval ?
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ctx->attrs.sample_interval : 1;
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unsigned long apply_interval = s->apply_interval_us ?
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s->apply_interval_us : ctx->attrs.aggr_interval;
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s->next_apply_sis = ctx->passed_sample_intervals +
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apply_interval / sample_interval;
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}
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void damon_add_scheme(struct damon_ctx *ctx, struct damos *s)
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{
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list_add_tail(&s->list, &ctx->schemes);
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damos_set_next_apply_sis(s, ctx);
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}
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static void damon_del_scheme(struct damos *s)
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{
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list_del(&s->list);
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}
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static void damon_free_scheme(struct damos *s)
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{
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kfree(s);
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}
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void damon_destroy_scheme(struct damos *s)
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{
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struct damos_quota_goal *g, *g_next;
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struct damos_filter *f, *next;
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damos_for_each_quota_goal_safe(g, g_next, &s->quota)
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damos_destroy_quota_goal(g);
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damos_for_each_filter_safe(f, next, s)
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damos_destroy_filter(f);
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damon_del_scheme(s);
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damon_free_scheme(s);
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}
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/*
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* Construct a damon_target struct
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*
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* Returns the pointer to the new struct if success, or NULL otherwise
|
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*/
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struct damon_target *damon_new_target(void)
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{
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struct damon_target *t;
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t = kmalloc(sizeof(*t), GFP_KERNEL);
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if (!t)
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return NULL;
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t->pid = NULL;
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t->nr_regions = 0;
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INIT_LIST_HEAD(&t->regions_list);
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INIT_LIST_HEAD(&t->list);
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return t;
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}
|
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|
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void damon_add_target(struct damon_ctx *ctx, struct damon_target *t)
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{
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list_add_tail(&t->list, &ctx->adaptive_targets);
|
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}
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bool damon_targets_empty(struct damon_ctx *ctx)
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{
|
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return list_empty(&ctx->adaptive_targets);
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}
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static void damon_del_target(struct damon_target *t)
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{
|
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list_del(&t->list);
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}
|
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void damon_free_target(struct damon_target *t)
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{
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struct damon_region *r, *next;
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damon_for_each_region_safe(r, next, t)
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damon_free_region(r);
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kfree(t);
|
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}
|
|
|
|
void damon_destroy_target(struct damon_target *t)
|
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{
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damon_del_target(t);
|
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damon_free_target(t);
|
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}
|
|
|
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unsigned int damon_nr_regions(struct damon_target *t)
|
|
{
|
|
return t->nr_regions;
|
|
}
|
|
|
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struct damon_ctx *damon_new_ctx(void)
|
|
{
|
|
struct damon_ctx *ctx;
|
|
|
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ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
|
|
if (!ctx)
|
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return NULL;
|
|
|
|
init_completion(&ctx->kdamond_started);
|
|
|
|
ctx->attrs.sample_interval = 5 * 1000;
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ctx->attrs.aggr_interval = 100 * 1000;
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ctx->attrs.ops_update_interval = 60 * 1000 * 1000;
|
|
|
|
ctx->passed_sample_intervals = 0;
|
|
/* These will be set from kdamond_init_intervals_sis() */
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ctx->next_aggregation_sis = 0;
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ctx->next_ops_update_sis = 0;
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mutex_init(&ctx->kdamond_lock);
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|
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ctx->attrs.min_nr_regions = 10;
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ctx->attrs.max_nr_regions = 1000;
|
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|
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INIT_LIST_HEAD(&ctx->adaptive_targets);
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INIT_LIST_HEAD(&ctx->schemes);
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return ctx;
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}
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|
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static void damon_destroy_targets(struct damon_ctx *ctx)
|
|
{
|
|
struct damon_target *t, *next_t;
|
|
|
|
if (ctx->ops.cleanup) {
|
|
ctx->ops.cleanup(ctx);
|
|
return;
|
|
}
|
|
|
|
damon_for_each_target_safe(t, next_t, ctx)
|
|
damon_destroy_target(t);
|
|
}
|
|
|
|
void damon_destroy_ctx(struct damon_ctx *ctx)
|
|
{
|
|
struct damos *s, *next_s;
|
|
|
|
damon_destroy_targets(ctx);
|
|
|
|
damon_for_each_scheme_safe(s, next_s, ctx)
|
|
damon_destroy_scheme(s);
|
|
|
|
kfree(ctx);
|
|
}
|
|
|
|
static unsigned int damon_age_for_new_attrs(unsigned int age,
|
|
struct damon_attrs *old_attrs, struct damon_attrs *new_attrs)
|
|
{
|
|
return age * old_attrs->aggr_interval / new_attrs->aggr_interval;
|
|
}
|
|
|
|
/* convert access ratio in bp (per 10,000) to nr_accesses */
|
|
static unsigned int damon_accesses_bp_to_nr_accesses(
|
|
unsigned int accesses_bp, struct damon_attrs *attrs)
|
|
{
|
|
return accesses_bp * damon_max_nr_accesses(attrs) / 10000;
|
|
}
|
|
|
|
/*
|
|
* Convert nr_accesses to access ratio in bp (per 10,000).
|
|
*
|
|
* Callers should ensure attrs.aggr_interval is not zero, like
|
|
* damon_update_monitoring_results() does . Otherwise, divide-by-zero would
|
|
* happen.
|
|
*/
|
|
static unsigned int damon_nr_accesses_to_accesses_bp(
|
|
unsigned int nr_accesses, struct damon_attrs *attrs)
|
|
{
|
|
return nr_accesses * 10000 / damon_max_nr_accesses(attrs);
|
|
}
|
|
|
|
static unsigned int damon_nr_accesses_for_new_attrs(unsigned int nr_accesses,
|
|
struct damon_attrs *old_attrs, struct damon_attrs *new_attrs)
|
|
{
|
|
return damon_accesses_bp_to_nr_accesses(
|
|
damon_nr_accesses_to_accesses_bp(
|
|
nr_accesses, old_attrs),
|
|
new_attrs);
|
|
}
|
|
|
|
static void damon_update_monitoring_result(struct damon_region *r,
|
|
struct damon_attrs *old_attrs, struct damon_attrs *new_attrs)
|
|
{
|
|
r->nr_accesses = damon_nr_accesses_for_new_attrs(r->nr_accesses,
|
|
old_attrs, new_attrs);
|
|
r->nr_accesses_bp = r->nr_accesses * 10000;
|
|
r->age = damon_age_for_new_attrs(r->age, old_attrs, new_attrs);
|
|
}
|
|
|
|
/*
|
|
* region->nr_accesses is the number of sampling intervals in the last
|
|
* aggregation interval that access to the region has found, and region->age is
|
|
* the number of aggregation intervals that its access pattern has maintained.
|
|
* For the reason, the real meaning of the two fields depend on current
|
|
* sampling interval and aggregation interval. This function updates
|
|
* ->nr_accesses and ->age of given damon_ctx's regions for new damon_attrs.
|
|
*/
|
|
static void damon_update_monitoring_results(struct damon_ctx *ctx,
|
|
struct damon_attrs *new_attrs)
|
|
{
|
|
struct damon_attrs *old_attrs = &ctx->attrs;
|
|
struct damon_target *t;
|
|
struct damon_region *r;
|
|
|
|
/* if any interval is zero, simply forgive conversion */
|
|
if (!old_attrs->sample_interval || !old_attrs->aggr_interval ||
|
|
!new_attrs->sample_interval ||
|
|
!new_attrs->aggr_interval)
|
|
return;
|
|
|
|
damon_for_each_target(t, ctx)
|
|
damon_for_each_region(r, t)
|
|
damon_update_monitoring_result(
|
|
r, old_attrs, new_attrs);
|
|
}
|
|
|
|
/**
|
|
* damon_set_attrs() - Set attributes for the monitoring.
|
|
* @ctx: monitoring context
|
|
* @attrs: monitoring attributes
|
|
*
|
|
* This function should be called while the kdamond is not running, or an
|
|
* access check results aggregation is not ongoing (e.g., from
|
|
* &struct damon_callback->after_aggregation or
|
|
* &struct damon_callback->after_wmarks_check callbacks).
|
|
*
|
|
* Every time interval is in micro-seconds.
|
|
*
|
|
* Return: 0 on success, negative error code otherwise.
|
|
*/
|
|
int damon_set_attrs(struct damon_ctx *ctx, struct damon_attrs *attrs)
|
|
{
|
|
unsigned long sample_interval = attrs->sample_interval ?
|
|
attrs->sample_interval : 1;
|
|
struct damos *s;
|
|
|
|
if (attrs->min_nr_regions < 3)
|
|
return -EINVAL;
|
|
if (attrs->min_nr_regions > attrs->max_nr_regions)
|
|
return -EINVAL;
|
|
if (attrs->sample_interval > attrs->aggr_interval)
|
|
return -EINVAL;
|
|
|
|
ctx->next_aggregation_sis = ctx->passed_sample_intervals +
|
|
attrs->aggr_interval / sample_interval;
|
|
ctx->next_ops_update_sis = ctx->passed_sample_intervals +
|
|
attrs->ops_update_interval / sample_interval;
|
|
|
|
damon_update_monitoring_results(ctx, attrs);
|
|
ctx->attrs = *attrs;
|
|
|
|
damon_for_each_scheme(s, ctx)
|
|
damos_set_next_apply_sis(s, ctx);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* damon_set_schemes() - Set data access monitoring based operation schemes.
|
|
* @ctx: monitoring context
|
|
* @schemes: array of the schemes
|
|
* @nr_schemes: number of entries in @schemes
|
|
*
|
|
* This function should not be called while the kdamond of the context is
|
|
* running.
|
|
*/
|
|
void damon_set_schemes(struct damon_ctx *ctx, struct damos **schemes,
|
|
ssize_t nr_schemes)
|
|
{
|
|
struct damos *s, *next;
|
|
ssize_t i;
|
|
|
|
damon_for_each_scheme_safe(s, next, ctx)
|
|
damon_destroy_scheme(s);
|
|
for (i = 0; i < nr_schemes; i++)
|
|
damon_add_scheme(ctx, schemes[i]);
|
|
}
|
|
|
|
static struct damos_quota_goal *damos_nth_quota_goal(
|
|
int n, struct damos_quota *q)
|
|
{
|
|
struct damos_quota_goal *goal;
|
|
int i = 0;
|
|
|
|
damos_for_each_quota_goal(goal, q) {
|
|
if (i++ == n)
|
|
return goal;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static void damos_commit_quota_goal(
|
|
struct damos_quota_goal *dst, struct damos_quota_goal *src)
|
|
{
|
|
dst->metric = src->metric;
|
|
dst->target_value = src->target_value;
|
|
if (dst->metric == DAMOS_QUOTA_USER_INPUT)
|
|
dst->current_value = src->current_value;
|
|
/* keep last_psi_total as is, since it will be updated in next cycle */
|
|
}
|
|
|
|
/**
|
|
* damos_commit_quota_goals() - Commit DAMOS quota goals to another quota.
|
|
* @dst: The commit destination DAMOS quota.
|
|
* @src: The commit source DAMOS quota.
|
|
*
|
|
* Copies user-specified parameters for quota goals from @src to @dst. Users
|
|
* should use this function for quota goals-level parameters update of running
|
|
* DAMON contexts, instead of manual in-place updates.
|
|
*
|
|
* This function should be called from parameters-update safe context, like
|
|
* DAMON callbacks.
|
|
*/
|
|
int damos_commit_quota_goals(struct damos_quota *dst, struct damos_quota *src)
|
|
{
|
|
struct damos_quota_goal *dst_goal, *next, *src_goal, *new_goal;
|
|
int i = 0, j = 0;
|
|
|
|
damos_for_each_quota_goal_safe(dst_goal, next, dst) {
|
|
src_goal = damos_nth_quota_goal(i++, src);
|
|
if (src_goal)
|
|
damos_commit_quota_goal(dst_goal, src_goal);
|
|
else
|
|
damos_destroy_quota_goal(dst_goal);
|
|
}
|
|
damos_for_each_quota_goal_safe(src_goal, next, src) {
|
|
if (j++ < i)
|
|
continue;
|
|
new_goal = damos_new_quota_goal(
|
|
src_goal->metric, src_goal->target_value);
|
|
if (!new_goal)
|
|
return -ENOMEM;
|
|
damos_add_quota_goal(dst, new_goal);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int damos_commit_quota(struct damos_quota *dst, struct damos_quota *src)
|
|
{
|
|
int err;
|
|
|
|
dst->reset_interval = src->reset_interval;
|
|
dst->ms = src->ms;
|
|
dst->sz = src->sz;
|
|
err = damos_commit_quota_goals(dst, src);
|
|
if (err)
|
|
return err;
|
|
dst->weight_sz = src->weight_sz;
|
|
dst->weight_nr_accesses = src->weight_nr_accesses;
|
|
dst->weight_age = src->weight_age;
|
|
return 0;
|
|
}
|
|
|
|
static struct damos_filter *damos_nth_filter(int n, struct damos *s)
|
|
{
|
|
struct damos_filter *filter;
|
|
int i = 0;
|
|
|
|
damos_for_each_filter(filter, s) {
|
|
if (i++ == n)
|
|
return filter;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static void damos_commit_filter_arg(
|
|
struct damos_filter *dst, struct damos_filter *src)
|
|
{
|
|
switch (dst->type) {
|
|
case DAMOS_FILTER_TYPE_MEMCG:
|
|
dst->memcg_id = src->memcg_id;
|
|
break;
|
|
case DAMOS_FILTER_TYPE_ADDR:
|
|
dst->addr_range = src->addr_range;
|
|
break;
|
|
case DAMOS_FILTER_TYPE_TARGET:
|
|
dst->target_idx = src->target_idx;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void damos_commit_filter(
|
|
struct damos_filter *dst, struct damos_filter *src)
|
|
{
|
|
dst->type = src->type;
|
|
dst->matching = src->matching;
|
|
damos_commit_filter_arg(dst, src);
|
|
}
|
|
|
|
static int damos_commit_filters(struct damos *dst, struct damos *src)
|
|
{
|
|
struct damos_filter *dst_filter, *next, *src_filter, *new_filter;
|
|
int i = 0, j = 0;
|
|
|
|
damos_for_each_filter_safe(dst_filter, next, dst) {
|
|
src_filter = damos_nth_filter(i++, src);
|
|
if (src_filter)
|
|
damos_commit_filter(dst_filter, src_filter);
|
|
else
|
|
damos_destroy_filter(dst_filter);
|
|
}
|
|
|
|
damos_for_each_filter_safe(src_filter, next, src) {
|
|
if (j++ < i)
|
|
continue;
|
|
|
|
new_filter = damos_new_filter(
|
|
src_filter->type, src_filter->matching);
|
|
if (!new_filter)
|
|
return -ENOMEM;
|
|
damos_commit_filter_arg(new_filter, src_filter);
|
|
damos_add_filter(dst, new_filter);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static struct damos *damon_nth_scheme(int n, struct damon_ctx *ctx)
|
|
{
|
|
struct damos *s;
|
|
int i = 0;
|
|
|
|
damon_for_each_scheme(s, ctx) {
|
|
if (i++ == n)
|
|
return s;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static int damos_commit(struct damos *dst, struct damos *src)
|
|
{
|
|
int err;
|
|
|
|
dst->pattern = src->pattern;
|
|
dst->action = src->action;
|
|
dst->apply_interval_us = src->apply_interval_us;
|
|
|
|
err = damos_commit_quota(&dst->quota, &src->quota);
|
|
if (err)
|
|
return err;
|
|
|
|
dst->wmarks = src->wmarks;
|
|
|
|
err = damos_commit_filters(dst, src);
|
|
return err;
|
|
}
|
|
|
|
static int damon_commit_schemes(struct damon_ctx *dst, struct damon_ctx *src)
|
|
{
|
|
struct damos *dst_scheme, *next, *src_scheme, *new_scheme;
|
|
int i = 0, j = 0, err;
|
|
|
|
damon_for_each_scheme_safe(dst_scheme, next, dst) {
|
|
src_scheme = damon_nth_scheme(i++, src);
|
|
if (src_scheme) {
|
|
err = damos_commit(dst_scheme, src_scheme);
|
|
if (err)
|
|
return err;
|
|
} else {
|
|
damon_destroy_scheme(dst_scheme);
|
|
}
|
|
}
|
|
|
|
damon_for_each_scheme_safe(src_scheme, next, src) {
|
|
if (j++ < i)
|
|
continue;
|
|
new_scheme = damon_new_scheme(&src_scheme->pattern,
|
|
src_scheme->action,
|
|
src_scheme->apply_interval_us,
|
|
&src_scheme->quota, &src_scheme->wmarks,
|
|
NUMA_NO_NODE);
|
|
if (!new_scheme)
|
|
return -ENOMEM;
|
|
damon_add_scheme(dst, new_scheme);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static struct damon_target *damon_nth_target(int n, struct damon_ctx *ctx)
|
|
{
|
|
struct damon_target *t;
|
|
int i = 0;
|
|
|
|
damon_for_each_target(t, ctx) {
|
|
if (i++ == n)
|
|
return t;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* The caller should ensure the regions of @src are
|
|
* 1. valid (end >= src) and
|
|
* 2. sorted by starting address.
|
|
*
|
|
* If @src has no region, @dst keeps current regions.
|
|
*/
|
|
static int damon_commit_target_regions(
|
|
struct damon_target *dst, struct damon_target *src)
|
|
{
|
|
struct damon_region *src_region;
|
|
struct damon_addr_range *ranges;
|
|
int i = 0, err;
|
|
|
|
damon_for_each_region(src_region, src)
|
|
i++;
|
|
if (!i)
|
|
return 0;
|
|
|
|
ranges = kmalloc_array(i, sizeof(*ranges), GFP_KERNEL | __GFP_NOWARN);
|
|
if (!ranges)
|
|
return -ENOMEM;
|
|
i = 0;
|
|
damon_for_each_region(src_region, src)
|
|
ranges[i++] = src_region->ar;
|
|
err = damon_set_regions(dst, ranges, i);
|
|
kfree(ranges);
|
|
return err;
|
|
}
|
|
|
|
static int damon_commit_target(
|
|
struct damon_target *dst, bool dst_has_pid,
|
|
struct damon_target *src, bool src_has_pid)
|
|
{
|
|
int err;
|
|
|
|
err = damon_commit_target_regions(dst, src);
|
|
if (err)
|
|
return err;
|
|
if (dst_has_pid)
|
|
put_pid(dst->pid);
|
|
if (src_has_pid)
|
|
get_pid(src->pid);
|
|
dst->pid = src->pid;
|
|
return 0;
|
|
}
|
|
|
|
static int damon_commit_targets(
|
|
struct damon_ctx *dst, struct damon_ctx *src)
|
|
{
|
|
struct damon_target *dst_target, *next, *src_target, *new_target;
|
|
int i = 0, j = 0, err;
|
|
|
|
damon_for_each_target_safe(dst_target, next, dst) {
|
|
src_target = damon_nth_target(i++, src);
|
|
if (src_target) {
|
|
err = damon_commit_target(
|
|
dst_target, damon_target_has_pid(dst),
|
|
src_target, damon_target_has_pid(src));
|
|
if (err)
|
|
return err;
|
|
} else {
|
|
if (damon_target_has_pid(dst))
|
|
put_pid(dst_target->pid);
|
|
damon_destroy_target(dst_target);
|
|
}
|
|
}
|
|
|
|
damon_for_each_target_safe(src_target, next, src) {
|
|
if (j++ < i)
|
|
continue;
|
|
new_target = damon_new_target();
|
|
if (!new_target)
|
|
return -ENOMEM;
|
|
err = damon_commit_target(new_target, false,
|
|
src_target, damon_target_has_pid(src));
|
|
if (err)
|
|
return err;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* damon_commit_ctx() - Commit parameters of a DAMON context to another.
|
|
* @dst: The commit destination DAMON context.
|
|
* @src: The commit source DAMON context.
|
|
*
|
|
* This function copies user-specified parameters from @src to @dst and update
|
|
* the internal status and results accordingly. Users should use this function
|
|
* for context-level parameters update of running context, instead of manual
|
|
* in-place updates.
|
|
*
|
|
* This function should be called from parameters-update safe context, like
|
|
* DAMON callbacks.
|
|
*/
|
|
int damon_commit_ctx(struct damon_ctx *dst, struct damon_ctx *src)
|
|
{
|
|
int err;
|
|
|
|
err = damon_commit_schemes(dst, src);
|
|
if (err)
|
|
return err;
|
|
err = damon_commit_targets(dst, src);
|
|
if (err)
|
|
return err;
|
|
/*
|
|
* schemes and targets should be updated first, since
|
|
* 1. damon_set_attrs() updates monitoring results of targets and
|
|
* next_apply_sis of schemes, and
|
|
* 2. ops update should be done after pid handling is done (target
|
|
* committing require putting pids).
|
|
*/
|
|
err = damon_set_attrs(dst, &src->attrs);
|
|
if (err)
|
|
return err;
|
|
dst->ops = src->ops;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* damon_nr_running_ctxs() - Return number of currently running contexts.
|
|
*/
|
|
int damon_nr_running_ctxs(void)
|
|
{
|
|
int nr_ctxs;
|
|
|
|
mutex_lock(&damon_lock);
|
|
nr_ctxs = nr_running_ctxs;
|
|
mutex_unlock(&damon_lock);
|
|
|
|
return nr_ctxs;
|
|
}
|
|
|
|
/* Returns the size upper limit for each monitoring region */
|
|
static unsigned long damon_region_sz_limit(struct damon_ctx *ctx)
|
|
{
|
|
struct damon_target *t;
|
|
struct damon_region *r;
|
|
unsigned long sz = 0;
|
|
|
|
damon_for_each_target(t, ctx) {
|
|
damon_for_each_region(r, t)
|
|
sz += damon_sz_region(r);
|
|
}
|
|
|
|
if (ctx->attrs.min_nr_regions)
|
|
sz /= ctx->attrs.min_nr_regions;
|
|
if (sz < DAMON_MIN_REGION)
|
|
sz = DAMON_MIN_REGION;
|
|
|
|
return sz;
|
|
}
|
|
|
|
static int kdamond_fn(void *data);
|
|
|
|
/*
|
|
* __damon_start() - Starts monitoring with given context.
|
|
* @ctx: monitoring context
|
|
*
|
|
* This function should be called while damon_lock is hold.
|
|
*
|
|
* Return: 0 on success, negative error code otherwise.
|
|
*/
|
|
static int __damon_start(struct damon_ctx *ctx)
|
|
{
|
|
int err = -EBUSY;
|
|
|
|
mutex_lock(&ctx->kdamond_lock);
|
|
if (!ctx->kdamond) {
|
|
err = 0;
|
|
reinit_completion(&ctx->kdamond_started);
|
|
ctx->kdamond = kthread_run(kdamond_fn, ctx, "kdamond.%d",
|
|
nr_running_ctxs);
|
|
if (IS_ERR(ctx->kdamond)) {
|
|
err = PTR_ERR(ctx->kdamond);
|
|
ctx->kdamond = NULL;
|
|
} else {
|
|
wait_for_completion(&ctx->kdamond_started);
|
|
}
|
|
}
|
|
mutex_unlock(&ctx->kdamond_lock);
|
|
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* damon_start() - Starts the monitorings for a given group of contexts.
|
|
* @ctxs: an array of the pointers for contexts to start monitoring
|
|
* @nr_ctxs: size of @ctxs
|
|
* @exclusive: exclusiveness of this contexts group
|
|
*
|
|
* This function starts a group of monitoring threads for a group of monitoring
|
|
* contexts. One thread per each context is created and run in parallel. The
|
|
* caller should handle synchronization between the threads by itself. If
|
|
* @exclusive is true and a group of threads that created by other
|
|
* 'damon_start()' call is currently running, this function does nothing but
|
|
* returns -EBUSY.
|
|
*
|
|
* Return: 0 on success, negative error code otherwise.
|
|
*/
|
|
int damon_start(struct damon_ctx **ctxs, int nr_ctxs, bool exclusive)
|
|
{
|
|
int i;
|
|
int err = 0;
|
|
|
|
mutex_lock(&damon_lock);
|
|
if ((exclusive && nr_running_ctxs) ||
|
|
(!exclusive && running_exclusive_ctxs)) {
|
|
mutex_unlock(&damon_lock);
|
|
return -EBUSY;
|
|
}
|
|
|
|
for (i = 0; i < nr_ctxs; i++) {
|
|
err = __damon_start(ctxs[i]);
|
|
if (err)
|
|
break;
|
|
nr_running_ctxs++;
|
|
}
|
|
if (exclusive && nr_running_ctxs)
|
|
running_exclusive_ctxs = true;
|
|
mutex_unlock(&damon_lock);
|
|
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* __damon_stop() - Stops monitoring of a given context.
|
|
* @ctx: monitoring context
|
|
*
|
|
* Return: 0 on success, negative error code otherwise.
|
|
*/
|
|
static int __damon_stop(struct damon_ctx *ctx)
|
|
{
|
|
struct task_struct *tsk;
|
|
|
|
mutex_lock(&ctx->kdamond_lock);
|
|
tsk = ctx->kdamond;
|
|
if (tsk) {
|
|
get_task_struct(tsk);
|
|
mutex_unlock(&ctx->kdamond_lock);
|
|
kthread_stop_put(tsk);
|
|
return 0;
|
|
}
|
|
mutex_unlock(&ctx->kdamond_lock);
|
|
|
|
return -EPERM;
|
|
}
|
|
|
|
/**
|
|
* damon_stop() - Stops the monitorings for a given group of contexts.
|
|
* @ctxs: an array of the pointers for contexts to stop monitoring
|
|
* @nr_ctxs: size of @ctxs
|
|
*
|
|
* Return: 0 on success, negative error code otherwise.
|
|
*/
|
|
int damon_stop(struct damon_ctx **ctxs, int nr_ctxs)
|
|
{
|
|
int i, err = 0;
|
|
|
|
for (i = 0; i < nr_ctxs; i++) {
|
|
/* nr_running_ctxs is decremented in kdamond_fn */
|
|
err = __damon_stop(ctxs[i]);
|
|
if (err)
|
|
break;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Reset the aggregated monitoring results ('nr_accesses' of each region).
|
|
*/
|
|
static void kdamond_reset_aggregated(struct damon_ctx *c)
|
|
{
|
|
struct damon_target *t;
|
|
unsigned int ti = 0; /* target's index */
|
|
|
|
damon_for_each_target(t, c) {
|
|
struct damon_region *r;
|
|
|
|
damon_for_each_region(r, t) {
|
|
trace_damon_aggregated(ti, r, damon_nr_regions(t));
|
|
r->last_nr_accesses = r->nr_accesses;
|
|
r->nr_accesses = 0;
|
|
}
|
|
ti++;
|
|
}
|
|
}
|
|
|
|
static void damon_split_region_at(struct damon_target *t,
|
|
struct damon_region *r, unsigned long sz_r);
|
|
|
|
static bool __damos_valid_target(struct damon_region *r, struct damos *s)
|
|
{
|
|
unsigned long sz;
|
|
unsigned int nr_accesses = r->nr_accesses_bp / 10000;
|
|
|
|
sz = damon_sz_region(r);
|
|
return s->pattern.min_sz_region <= sz &&
|
|
sz <= s->pattern.max_sz_region &&
|
|
s->pattern.min_nr_accesses <= nr_accesses &&
|
|
nr_accesses <= s->pattern.max_nr_accesses &&
|
|
s->pattern.min_age_region <= r->age &&
|
|
r->age <= s->pattern.max_age_region;
|
|
}
|
|
|
|
static bool damos_valid_target(struct damon_ctx *c, struct damon_target *t,
|
|
struct damon_region *r, struct damos *s)
|
|
{
|
|
bool ret = __damos_valid_target(r, s);
|
|
|
|
if (!ret || !s->quota.esz || !c->ops.get_scheme_score)
|
|
return ret;
|
|
|
|
return c->ops.get_scheme_score(c, t, r, s) >= s->quota.min_score;
|
|
}
|
|
|
|
/*
|
|
* damos_skip_charged_region() - Check if the given region or starting part of
|
|
* it is already charged for the DAMOS quota.
|
|
* @t: The target of the region.
|
|
* @rp: The pointer to the region.
|
|
* @s: The scheme to be applied.
|
|
*
|
|
* If a quota of a scheme has exceeded in a quota charge window, the scheme's
|
|
* action would applied to only a part of the target access pattern fulfilling
|
|
* regions. To avoid applying the scheme action to only already applied
|
|
* regions, DAMON skips applying the scheme action to the regions that charged
|
|
* in the previous charge window.
|
|
*
|
|
* This function checks if a given region should be skipped or not for the
|
|
* reason. If only the starting part of the region has previously charged,
|
|
* this function splits the region into two so that the second one covers the
|
|
* area that not charged in the previous charge widnow and saves the second
|
|
* region in *rp and returns false, so that the caller can apply DAMON action
|
|
* to the second one.
|
|
*
|
|
* Return: true if the region should be entirely skipped, false otherwise.
|
|
*/
|
|
static bool damos_skip_charged_region(struct damon_target *t,
|
|
struct damon_region **rp, struct damos *s)
|
|
{
|
|
struct damon_region *r = *rp;
|
|
struct damos_quota *quota = &s->quota;
|
|
unsigned long sz_to_skip;
|
|
|
|
/* Skip previously charged regions */
|
|
if (quota->charge_target_from) {
|
|
if (t != quota->charge_target_from)
|
|
return true;
|
|
if (r == damon_last_region(t)) {
|
|
quota->charge_target_from = NULL;
|
|
quota->charge_addr_from = 0;
|
|
return true;
|
|
}
|
|
if (quota->charge_addr_from &&
|
|
r->ar.end <= quota->charge_addr_from)
|
|
return true;
|
|
|
|
if (quota->charge_addr_from && r->ar.start <
|
|
quota->charge_addr_from) {
|
|
sz_to_skip = ALIGN_DOWN(quota->charge_addr_from -
|
|
r->ar.start, DAMON_MIN_REGION);
|
|
if (!sz_to_skip) {
|
|
if (damon_sz_region(r) <= DAMON_MIN_REGION)
|
|
return true;
|
|
sz_to_skip = DAMON_MIN_REGION;
|
|
}
|
|
damon_split_region_at(t, r, sz_to_skip);
|
|
r = damon_next_region(r);
|
|
*rp = r;
|
|
}
|
|
quota->charge_target_from = NULL;
|
|
quota->charge_addr_from = 0;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static void damos_update_stat(struct damos *s,
|
|
unsigned long sz_tried, unsigned long sz_applied)
|
|
{
|
|
s->stat.nr_tried++;
|
|
s->stat.sz_tried += sz_tried;
|
|
if (sz_applied)
|
|
s->stat.nr_applied++;
|
|
s->stat.sz_applied += sz_applied;
|
|
}
|
|
|
|
static bool __damos_filter_out(struct damon_ctx *ctx, struct damon_target *t,
|
|
struct damon_region *r, struct damos_filter *filter)
|
|
{
|
|
bool matched = false;
|
|
struct damon_target *ti;
|
|
int target_idx = 0;
|
|
unsigned long start, end;
|
|
|
|
switch (filter->type) {
|
|
case DAMOS_FILTER_TYPE_TARGET:
|
|
damon_for_each_target(ti, ctx) {
|
|
if (ti == t)
|
|
break;
|
|
target_idx++;
|
|
}
|
|
matched = target_idx == filter->target_idx;
|
|
break;
|
|
case DAMOS_FILTER_TYPE_ADDR:
|
|
start = ALIGN_DOWN(filter->addr_range.start, DAMON_MIN_REGION);
|
|
end = ALIGN_DOWN(filter->addr_range.end, DAMON_MIN_REGION);
|
|
|
|
/* inside the range */
|
|
if (start <= r->ar.start && r->ar.end <= end) {
|
|
matched = true;
|
|
break;
|
|
}
|
|
/* outside of the range */
|
|
if (r->ar.end <= start || end <= r->ar.start) {
|
|
matched = false;
|
|
break;
|
|
}
|
|
/* start before the range and overlap */
|
|
if (r->ar.start < start) {
|
|
damon_split_region_at(t, r, start - r->ar.start);
|
|
matched = false;
|
|
break;
|
|
}
|
|
/* start inside the range */
|
|
damon_split_region_at(t, r, end - r->ar.start);
|
|
matched = true;
|
|
break;
|
|
default:
|
|
return false;
|
|
}
|
|
|
|
return matched == filter->matching;
|
|
}
|
|
|
|
static bool damos_filter_out(struct damon_ctx *ctx, struct damon_target *t,
|
|
struct damon_region *r, struct damos *s)
|
|
{
|
|
struct damos_filter *filter;
|
|
|
|
damos_for_each_filter(filter, s) {
|
|
if (__damos_filter_out(ctx, t, r, filter))
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static void damos_apply_scheme(struct damon_ctx *c, struct damon_target *t,
|
|
struct damon_region *r, struct damos *s)
|
|
{
|
|
struct damos_quota *quota = &s->quota;
|
|
unsigned long sz = damon_sz_region(r);
|
|
struct timespec64 begin, end;
|
|
unsigned long sz_applied = 0;
|
|
int err = 0;
|
|
/*
|
|
* We plan to support multiple context per kdamond, as DAMON sysfs
|
|
* implies with 'nr_contexts' file. Nevertheless, only single context
|
|
* per kdamond is supported for now. So, we can simply use '0' context
|
|
* index here.
|
|
*/
|
|
unsigned int cidx = 0;
|
|
struct damos *siter; /* schemes iterator */
|
|
unsigned int sidx = 0;
|
|
struct damon_target *titer; /* targets iterator */
|
|
unsigned int tidx = 0;
|
|
bool do_trace = false;
|
|
|
|
/* get indices for trace_damos_before_apply() */
|
|
if (trace_damos_before_apply_enabled()) {
|
|
damon_for_each_scheme(siter, c) {
|
|
if (siter == s)
|
|
break;
|
|
sidx++;
|
|
}
|
|
damon_for_each_target(titer, c) {
|
|
if (titer == t)
|
|
break;
|
|
tidx++;
|
|
}
|
|
do_trace = true;
|
|
}
|
|
|
|
if (c->ops.apply_scheme) {
|
|
if (quota->esz && quota->charged_sz + sz > quota->esz) {
|
|
sz = ALIGN_DOWN(quota->esz - quota->charged_sz,
|
|
DAMON_MIN_REGION);
|
|
if (!sz)
|
|
goto update_stat;
|
|
damon_split_region_at(t, r, sz);
|
|
}
|
|
if (damos_filter_out(c, t, r, s))
|
|
return;
|
|
ktime_get_coarse_ts64(&begin);
|
|
if (c->callback.before_damos_apply)
|
|
err = c->callback.before_damos_apply(c, t, r, s);
|
|
if (!err) {
|
|
trace_damos_before_apply(cidx, sidx, tidx, r,
|
|
damon_nr_regions(t), do_trace);
|
|
sz_applied = c->ops.apply_scheme(c, t, r, s);
|
|
}
|
|
ktime_get_coarse_ts64(&end);
|
|
quota->total_charged_ns += timespec64_to_ns(&end) -
|
|
timespec64_to_ns(&begin);
|
|
quota->charged_sz += sz;
|
|
if (quota->esz && quota->charged_sz >= quota->esz) {
|
|
quota->charge_target_from = t;
|
|
quota->charge_addr_from = r->ar.end + 1;
|
|
}
|
|
}
|
|
if (s->action != DAMOS_STAT)
|
|
r->age = 0;
|
|
|
|
update_stat:
|
|
damos_update_stat(s, sz, sz_applied);
|
|
}
|
|
|
|
static void damon_do_apply_schemes(struct damon_ctx *c,
|
|
struct damon_target *t,
|
|
struct damon_region *r)
|
|
{
|
|
struct damos *s;
|
|
|
|
damon_for_each_scheme(s, c) {
|
|
struct damos_quota *quota = &s->quota;
|
|
|
|
if (c->passed_sample_intervals != s->next_apply_sis)
|
|
continue;
|
|
|
|
if (!s->wmarks.activated)
|
|
continue;
|
|
|
|
/* Check the quota */
|
|
if (quota->esz && quota->charged_sz >= quota->esz)
|
|
continue;
|
|
|
|
if (damos_skip_charged_region(t, &r, s))
|
|
continue;
|
|
|
|
if (!damos_valid_target(c, t, r, s))
|
|
continue;
|
|
|
|
damos_apply_scheme(c, t, r, s);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* damon_feed_loop_next_input() - get next input to achieve a target score.
|
|
* @last_input The last input.
|
|
* @score Current score that made with @last_input.
|
|
*
|
|
* Calculate next input to achieve the target score, based on the last input
|
|
* and current score. Assuming the input and the score are positively
|
|
* proportional, calculate how much compensation should be added to or
|
|
* subtracted from the last input as a proportion of the last input. Avoid
|
|
* next input always being zero by setting it non-zero always. In short form
|
|
* (assuming support of float and signed calculations), the algorithm is as
|
|
* below.
|
|
*
|
|
* next_input = max(last_input * ((goal - current) / goal + 1), 1)
|
|
*
|
|
* For simple implementation, we assume the target score is always 10,000. The
|
|
* caller should adjust @score for this.
|
|
*
|
|
* Returns next input that assumed to achieve the target score.
|
|
*/
|
|
static unsigned long damon_feed_loop_next_input(unsigned long last_input,
|
|
unsigned long score)
|
|
{
|
|
const unsigned long goal = 10000;
|
|
unsigned long score_goal_diff = max(goal, score) - min(goal, score);
|
|
unsigned long score_goal_diff_bp = score_goal_diff * 10000 / goal;
|
|
unsigned long compensation = last_input * score_goal_diff_bp / 10000;
|
|
/* Set minimum input as 10000 to avoid compensation be zero */
|
|
const unsigned long min_input = 10000;
|
|
|
|
if (goal > score)
|
|
return last_input + compensation;
|
|
if (last_input > compensation + min_input)
|
|
return last_input - compensation;
|
|
return min_input;
|
|
}
|
|
|
|
#ifdef CONFIG_PSI
|
|
|
|
static u64 damos_get_some_mem_psi_total(void)
|
|
{
|
|
if (static_branch_likely(&psi_disabled))
|
|
return 0;
|
|
return div_u64(psi_system.total[PSI_AVGS][PSI_MEM * 2],
|
|
NSEC_PER_USEC);
|
|
}
|
|
|
|
#else /* CONFIG_PSI */
|
|
|
|
static inline u64 damos_get_some_mem_psi_total(void)
|
|
{
|
|
return 0;
|
|
};
|
|
|
|
#endif /* CONFIG_PSI */
|
|
|
|
static void damos_set_quota_goal_current_value(struct damos_quota_goal *goal)
|
|
{
|
|
u64 now_psi_total;
|
|
|
|
switch (goal->metric) {
|
|
case DAMOS_QUOTA_USER_INPUT:
|
|
/* User should already set goal->current_value */
|
|
break;
|
|
case DAMOS_QUOTA_SOME_MEM_PSI_US:
|
|
now_psi_total = damos_get_some_mem_psi_total();
|
|
goal->current_value = now_psi_total - goal->last_psi_total;
|
|
goal->last_psi_total = now_psi_total;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Return the highest score since it makes schemes least aggressive */
|
|
static unsigned long damos_quota_score(struct damos_quota *quota)
|
|
{
|
|
struct damos_quota_goal *goal;
|
|
unsigned long highest_score = 0;
|
|
|
|
damos_for_each_quota_goal(goal, quota) {
|
|
damos_set_quota_goal_current_value(goal);
|
|
highest_score = max(highest_score,
|
|
goal->current_value * 10000 /
|
|
goal->target_value);
|
|
}
|
|
|
|
return highest_score;
|
|
}
|
|
|
|
/*
|
|
* Called only if quota->ms, or quota->sz are set, or quota->goals is not empty
|
|
*/
|
|
static void damos_set_effective_quota(struct damos_quota *quota)
|
|
{
|
|
unsigned long throughput;
|
|
unsigned long esz;
|
|
|
|
if (!quota->ms && list_empty("a->goals)) {
|
|
quota->esz = quota->sz;
|
|
return;
|
|
}
|
|
|
|
if (!list_empty("a->goals)) {
|
|
unsigned long score = damos_quota_score(quota);
|
|
|
|
quota->esz_bp = damon_feed_loop_next_input(
|
|
max(quota->esz_bp, 10000UL),
|
|
score);
|
|
esz = quota->esz_bp / 10000;
|
|
}
|
|
|
|
if (quota->ms) {
|
|
if (quota->total_charged_ns)
|
|
throughput = quota->total_charged_sz * 1000000 /
|
|
quota->total_charged_ns;
|
|
else
|
|
throughput = PAGE_SIZE * 1024;
|
|
if (!list_empty("a->goals))
|
|
esz = min(throughput * quota->ms, esz);
|
|
else
|
|
esz = throughput * quota->ms;
|
|
}
|
|
|
|
if (quota->sz && quota->sz < esz)
|
|
esz = quota->sz;
|
|
|
|
quota->esz = esz;
|
|
}
|
|
|
|
static void damos_adjust_quota(struct damon_ctx *c, struct damos *s)
|
|
{
|
|
struct damos_quota *quota = &s->quota;
|
|
struct damon_target *t;
|
|
struct damon_region *r;
|
|
unsigned long cumulated_sz;
|
|
unsigned int score, max_score = 0;
|
|
|
|
if (!quota->ms && !quota->sz && list_empty("a->goals))
|
|
return;
|
|
|
|
/* New charge window starts */
|
|
if (time_after_eq(jiffies, quota->charged_from +
|
|
msecs_to_jiffies(quota->reset_interval))) {
|
|
if (quota->esz && quota->charged_sz >= quota->esz)
|
|
s->stat.qt_exceeds++;
|
|
quota->total_charged_sz += quota->charged_sz;
|
|
quota->charged_from = jiffies;
|
|
quota->charged_sz = 0;
|
|
damos_set_effective_quota(quota);
|
|
}
|
|
|
|
if (!c->ops.get_scheme_score)
|
|
return;
|
|
|
|
/* Fill up the score histogram */
|
|
memset(c->regions_score_histogram, 0,
|
|
sizeof(*c->regions_score_histogram) *
|
|
(DAMOS_MAX_SCORE + 1));
|
|
damon_for_each_target(t, c) {
|
|
damon_for_each_region(r, t) {
|
|
if (!__damos_valid_target(r, s))
|
|
continue;
|
|
score = c->ops.get_scheme_score(c, t, r, s);
|
|
c->regions_score_histogram[score] +=
|
|
damon_sz_region(r);
|
|
if (score > max_score)
|
|
max_score = score;
|
|
}
|
|
}
|
|
|
|
/* Set the min score limit */
|
|
for (cumulated_sz = 0, score = max_score; ; score--) {
|
|
cumulated_sz += c->regions_score_histogram[score];
|
|
if (cumulated_sz >= quota->esz || !score)
|
|
break;
|
|
}
|
|
quota->min_score = score;
|
|
}
|
|
|
|
static void kdamond_apply_schemes(struct damon_ctx *c)
|
|
{
|
|
struct damon_target *t;
|
|
struct damon_region *r, *next_r;
|
|
struct damos *s;
|
|
unsigned long sample_interval = c->attrs.sample_interval ?
|
|
c->attrs.sample_interval : 1;
|
|
bool has_schemes_to_apply = false;
|
|
|
|
damon_for_each_scheme(s, c) {
|
|
if (c->passed_sample_intervals != s->next_apply_sis)
|
|
continue;
|
|
|
|
if (!s->wmarks.activated)
|
|
continue;
|
|
|
|
has_schemes_to_apply = true;
|
|
|
|
damos_adjust_quota(c, s);
|
|
}
|
|
|
|
if (!has_schemes_to_apply)
|
|
return;
|
|
|
|
damon_for_each_target(t, c) {
|
|
damon_for_each_region_safe(r, next_r, t)
|
|
damon_do_apply_schemes(c, t, r);
|
|
}
|
|
|
|
damon_for_each_scheme(s, c) {
|
|
if (c->passed_sample_intervals != s->next_apply_sis)
|
|
continue;
|
|
s->next_apply_sis +=
|
|
(s->apply_interval_us ? s->apply_interval_us :
|
|
c->attrs.aggr_interval) / sample_interval;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Merge two adjacent regions into one region
|
|
*/
|
|
static void damon_merge_two_regions(struct damon_target *t,
|
|
struct damon_region *l, struct damon_region *r)
|
|
{
|
|
unsigned long sz_l = damon_sz_region(l), sz_r = damon_sz_region(r);
|
|
|
|
l->nr_accesses = (l->nr_accesses * sz_l + r->nr_accesses * sz_r) /
|
|
(sz_l + sz_r);
|
|
l->nr_accesses_bp = l->nr_accesses * 10000;
|
|
l->age = (l->age * sz_l + r->age * sz_r) / (sz_l + sz_r);
|
|
l->ar.end = r->ar.end;
|
|
damon_destroy_region(r, t);
|
|
}
|
|
|
|
/*
|
|
* Merge adjacent regions having similar access frequencies
|
|
*
|
|
* t target affected by this merge operation
|
|
* thres '->nr_accesses' diff threshold for the merge
|
|
* sz_limit size upper limit of each region
|
|
*/
|
|
static void damon_merge_regions_of(struct damon_target *t, unsigned int thres,
|
|
unsigned long sz_limit)
|
|
{
|
|
struct damon_region *r, *prev = NULL, *next;
|
|
|
|
damon_for_each_region_safe(r, next, t) {
|
|
if (abs(r->nr_accesses - r->last_nr_accesses) > thres)
|
|
r->age = 0;
|
|
else
|
|
r->age++;
|
|
|
|
if (prev && prev->ar.end == r->ar.start &&
|
|
abs(prev->nr_accesses - r->nr_accesses) <= thres &&
|
|
damon_sz_region(prev) + damon_sz_region(r) <= sz_limit)
|
|
damon_merge_two_regions(t, prev, r);
|
|
else
|
|
prev = r;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Merge adjacent regions having similar access frequencies
|
|
*
|
|
* threshold '->nr_accesses' diff threshold for the merge
|
|
* sz_limit size upper limit of each region
|
|
*
|
|
* This function merges monitoring target regions which are adjacent and their
|
|
* access frequencies are similar. This is for minimizing the monitoring
|
|
* overhead under the dynamically changeable access pattern. If a merge was
|
|
* unnecessarily made, later 'kdamond_split_regions()' will revert it.
|
|
*
|
|
* The total number of regions could be higher than the user-defined limit,
|
|
* max_nr_regions for some cases. For example, the user can update
|
|
* max_nr_regions to a number that lower than the current number of regions
|
|
* while DAMON is running. For such a case, repeat merging until the limit is
|
|
* met while increasing @threshold up to possible maximum level.
|
|
*/
|
|
static void kdamond_merge_regions(struct damon_ctx *c, unsigned int threshold,
|
|
unsigned long sz_limit)
|
|
{
|
|
struct damon_target *t;
|
|
unsigned int nr_regions;
|
|
unsigned int max_thres;
|
|
|
|
max_thres = c->attrs.aggr_interval /
|
|
(c->attrs.sample_interval ? c->attrs.sample_interval : 1);
|
|
do {
|
|
nr_regions = 0;
|
|
damon_for_each_target(t, c) {
|
|
damon_merge_regions_of(t, threshold, sz_limit);
|
|
nr_regions += damon_nr_regions(t);
|
|
}
|
|
threshold = max(1, threshold * 2);
|
|
} while (nr_regions > c->attrs.max_nr_regions &&
|
|
threshold / 2 < max_thres);
|
|
}
|
|
|
|
/*
|
|
* Split a region in two
|
|
*
|
|
* r the region to be split
|
|
* sz_r size of the first sub-region that will be made
|
|
*/
|
|
static void damon_split_region_at(struct damon_target *t,
|
|
struct damon_region *r, unsigned long sz_r)
|
|
{
|
|
struct damon_region *new;
|
|
|
|
new = damon_new_region(r->ar.start + sz_r, r->ar.end);
|
|
if (!new)
|
|
return;
|
|
|
|
r->ar.end = new->ar.start;
|
|
|
|
new->age = r->age;
|
|
new->last_nr_accesses = r->last_nr_accesses;
|
|
new->nr_accesses_bp = r->nr_accesses_bp;
|
|
new->nr_accesses = r->nr_accesses;
|
|
|
|
damon_insert_region(new, r, damon_next_region(r), t);
|
|
}
|
|
|
|
/* Split every region in the given target into 'nr_subs' regions */
|
|
static void damon_split_regions_of(struct damon_target *t, int nr_subs)
|
|
{
|
|
struct damon_region *r, *next;
|
|
unsigned long sz_region, sz_sub = 0;
|
|
int i;
|
|
|
|
damon_for_each_region_safe(r, next, t) {
|
|
sz_region = damon_sz_region(r);
|
|
|
|
for (i = 0; i < nr_subs - 1 &&
|
|
sz_region > 2 * DAMON_MIN_REGION; i++) {
|
|
/*
|
|
* Randomly select size of left sub-region to be at
|
|
* least 10 percent and at most 90% of original region
|
|
*/
|
|
sz_sub = ALIGN_DOWN(damon_rand(1, 10) *
|
|
sz_region / 10, DAMON_MIN_REGION);
|
|
/* Do not allow blank region */
|
|
if (sz_sub == 0 || sz_sub >= sz_region)
|
|
continue;
|
|
|
|
damon_split_region_at(t, r, sz_sub);
|
|
sz_region = sz_sub;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Split every target region into randomly-sized small regions
|
|
*
|
|
* This function splits every target region into random-sized small regions if
|
|
* current total number of the regions is equal or smaller than half of the
|
|
* user-specified maximum number of regions. This is for maximizing the
|
|
* monitoring accuracy under the dynamically changeable access patterns. If a
|
|
* split was unnecessarily made, later 'kdamond_merge_regions()' will revert
|
|
* it.
|
|
*/
|
|
static void kdamond_split_regions(struct damon_ctx *ctx)
|
|
{
|
|
struct damon_target *t;
|
|
unsigned int nr_regions = 0;
|
|
static unsigned int last_nr_regions;
|
|
int nr_subregions = 2;
|
|
|
|
damon_for_each_target(t, ctx)
|
|
nr_regions += damon_nr_regions(t);
|
|
|
|
if (nr_regions > ctx->attrs.max_nr_regions / 2)
|
|
return;
|
|
|
|
/* Maybe the middle of the region has different access frequency */
|
|
if (last_nr_regions == nr_regions &&
|
|
nr_regions < ctx->attrs.max_nr_regions / 3)
|
|
nr_subregions = 3;
|
|
|
|
damon_for_each_target(t, ctx)
|
|
damon_split_regions_of(t, nr_subregions);
|
|
|
|
last_nr_regions = nr_regions;
|
|
}
|
|
|
|
/*
|
|
* Check whether current monitoring should be stopped
|
|
*
|
|
* The monitoring is stopped when either the user requested to stop, or all
|
|
* monitoring targets are invalid.
|
|
*
|
|
* Returns true if need to stop current monitoring.
|
|
*/
|
|
static bool kdamond_need_stop(struct damon_ctx *ctx)
|
|
{
|
|
struct damon_target *t;
|
|
|
|
if (kthread_should_stop())
|
|
return true;
|
|
|
|
if (!ctx->ops.target_valid)
|
|
return false;
|
|
|
|
damon_for_each_target(t, ctx) {
|
|
if (ctx->ops.target_valid(t))
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static int damos_get_wmark_metric_value(enum damos_wmark_metric metric,
|
|
unsigned long *metric_value)
|
|
{
|
|
switch (metric) {
|
|
case DAMOS_WMARK_FREE_MEM_RATE:
|
|
*metric_value = global_zone_page_state(NR_FREE_PAGES) * 1000 /
|
|
totalram_pages();
|
|
return 0;
|
|
default:
|
|
break;
|
|
}
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*
|
|
* Returns zero if the scheme is active. Else, returns time to wait for next
|
|
* watermark check in micro-seconds.
|
|
*/
|
|
static unsigned long damos_wmark_wait_us(struct damos *scheme)
|
|
{
|
|
unsigned long metric;
|
|
|
|
if (damos_get_wmark_metric_value(scheme->wmarks.metric, &metric))
|
|
return 0;
|
|
|
|
/* higher than high watermark or lower than low watermark */
|
|
if (metric > scheme->wmarks.high || scheme->wmarks.low > metric) {
|
|
if (scheme->wmarks.activated)
|
|
pr_debug("deactivate a scheme (%d) for %s wmark\n",
|
|
scheme->action,
|
|
metric > scheme->wmarks.high ?
|
|
"high" : "low");
|
|
scheme->wmarks.activated = false;
|
|
return scheme->wmarks.interval;
|
|
}
|
|
|
|
/* inactive and higher than middle watermark */
|
|
if ((scheme->wmarks.high >= metric && metric >= scheme->wmarks.mid) &&
|
|
!scheme->wmarks.activated)
|
|
return scheme->wmarks.interval;
|
|
|
|
if (!scheme->wmarks.activated)
|
|
pr_debug("activate a scheme (%d)\n", scheme->action);
|
|
scheme->wmarks.activated = true;
|
|
return 0;
|
|
}
|
|
|
|
static void kdamond_usleep(unsigned long usecs)
|
|
{
|
|
/* See Documentation/timers/timers-howto.rst for the thresholds */
|
|
if (usecs > 20 * USEC_PER_MSEC)
|
|
schedule_timeout_idle(usecs_to_jiffies(usecs));
|
|
else
|
|
usleep_idle_range(usecs, usecs + 1);
|
|
}
|
|
|
|
/* Returns negative error code if it's not activated but should return */
|
|
static int kdamond_wait_activation(struct damon_ctx *ctx)
|
|
{
|
|
struct damos *s;
|
|
unsigned long wait_time;
|
|
unsigned long min_wait_time = 0;
|
|
bool init_wait_time = false;
|
|
|
|
while (!kdamond_need_stop(ctx)) {
|
|
damon_for_each_scheme(s, ctx) {
|
|
wait_time = damos_wmark_wait_us(s);
|
|
if (!init_wait_time || wait_time < min_wait_time) {
|
|
init_wait_time = true;
|
|
min_wait_time = wait_time;
|
|
}
|
|
}
|
|
if (!min_wait_time)
|
|
return 0;
|
|
|
|
kdamond_usleep(min_wait_time);
|
|
|
|
if (ctx->callback.after_wmarks_check &&
|
|
ctx->callback.after_wmarks_check(ctx))
|
|
break;
|
|
}
|
|
return -EBUSY;
|
|
}
|
|
|
|
static void kdamond_init_intervals_sis(struct damon_ctx *ctx)
|
|
{
|
|
unsigned long sample_interval = ctx->attrs.sample_interval ?
|
|
ctx->attrs.sample_interval : 1;
|
|
unsigned long apply_interval;
|
|
struct damos *scheme;
|
|
|
|
ctx->passed_sample_intervals = 0;
|
|
ctx->next_aggregation_sis = ctx->attrs.aggr_interval / sample_interval;
|
|
ctx->next_ops_update_sis = ctx->attrs.ops_update_interval /
|
|
sample_interval;
|
|
|
|
damon_for_each_scheme(scheme, ctx) {
|
|
apply_interval = scheme->apply_interval_us ?
|
|
scheme->apply_interval_us : ctx->attrs.aggr_interval;
|
|
scheme->next_apply_sis = apply_interval / sample_interval;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* The monitoring daemon that runs as a kernel thread
|
|
*/
|
|
static int kdamond_fn(void *data)
|
|
{
|
|
struct damon_ctx *ctx = data;
|
|
struct damon_target *t;
|
|
struct damon_region *r, *next;
|
|
unsigned int max_nr_accesses = 0;
|
|
unsigned long sz_limit = 0;
|
|
|
|
pr_debug("kdamond (%d) starts\n", current->pid);
|
|
|
|
complete(&ctx->kdamond_started);
|
|
kdamond_init_intervals_sis(ctx);
|
|
|
|
if (ctx->ops.init)
|
|
ctx->ops.init(ctx);
|
|
if (ctx->callback.before_start && ctx->callback.before_start(ctx))
|
|
goto done;
|
|
ctx->regions_score_histogram = kmalloc_array(DAMOS_MAX_SCORE + 1,
|
|
sizeof(*ctx->regions_score_histogram), GFP_KERNEL);
|
|
if (!ctx->regions_score_histogram)
|
|
goto done;
|
|
|
|
sz_limit = damon_region_sz_limit(ctx);
|
|
|
|
while (!kdamond_need_stop(ctx)) {
|
|
/*
|
|
* ctx->attrs and ctx->next_{aggregation,ops_update}_sis could
|
|
* be changed from after_wmarks_check() or after_aggregation()
|
|
* callbacks. Read the values here, and use those for this
|
|
* iteration. That is, damon_set_attrs() updated new values
|
|
* are respected from next iteration.
|
|
*/
|
|
unsigned long next_aggregation_sis = ctx->next_aggregation_sis;
|
|
unsigned long next_ops_update_sis = ctx->next_ops_update_sis;
|
|
unsigned long sample_interval = ctx->attrs.sample_interval;
|
|
|
|
if (kdamond_wait_activation(ctx))
|
|
break;
|
|
|
|
if (ctx->ops.prepare_access_checks)
|
|
ctx->ops.prepare_access_checks(ctx);
|
|
if (ctx->callback.after_sampling &&
|
|
ctx->callback.after_sampling(ctx))
|
|
break;
|
|
|
|
kdamond_usleep(sample_interval);
|
|
ctx->passed_sample_intervals++;
|
|
|
|
if (ctx->ops.check_accesses)
|
|
max_nr_accesses = ctx->ops.check_accesses(ctx);
|
|
|
|
if (ctx->passed_sample_intervals == next_aggregation_sis) {
|
|
kdamond_merge_regions(ctx,
|
|
max_nr_accesses / 10,
|
|
sz_limit);
|
|
if (ctx->callback.after_aggregation &&
|
|
ctx->callback.after_aggregation(ctx))
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* do kdamond_apply_schemes() after kdamond_merge_regions() if
|
|
* possible, to reduce overhead
|
|
*/
|
|
if (!list_empty(&ctx->schemes))
|
|
kdamond_apply_schemes(ctx);
|
|
|
|
sample_interval = ctx->attrs.sample_interval ?
|
|
ctx->attrs.sample_interval : 1;
|
|
if (ctx->passed_sample_intervals == next_aggregation_sis) {
|
|
ctx->next_aggregation_sis = next_aggregation_sis +
|
|
ctx->attrs.aggr_interval / sample_interval;
|
|
|
|
kdamond_reset_aggregated(ctx);
|
|
kdamond_split_regions(ctx);
|
|
if (ctx->ops.reset_aggregated)
|
|
ctx->ops.reset_aggregated(ctx);
|
|
}
|
|
|
|
if (ctx->passed_sample_intervals == next_ops_update_sis) {
|
|
ctx->next_ops_update_sis = next_ops_update_sis +
|
|
ctx->attrs.ops_update_interval /
|
|
sample_interval;
|
|
if (ctx->ops.update)
|
|
ctx->ops.update(ctx);
|
|
sz_limit = damon_region_sz_limit(ctx);
|
|
}
|
|
}
|
|
done:
|
|
damon_for_each_target(t, ctx) {
|
|
damon_for_each_region_safe(r, next, t)
|
|
damon_destroy_region(r, t);
|
|
}
|
|
|
|
if (ctx->callback.before_terminate)
|
|
ctx->callback.before_terminate(ctx);
|
|
if (ctx->ops.cleanup)
|
|
ctx->ops.cleanup(ctx);
|
|
kfree(ctx->regions_score_histogram);
|
|
|
|
pr_debug("kdamond (%d) finishes\n", current->pid);
|
|
mutex_lock(&ctx->kdamond_lock);
|
|
ctx->kdamond = NULL;
|
|
mutex_unlock(&ctx->kdamond_lock);
|
|
|
|
mutex_lock(&damon_lock);
|
|
nr_running_ctxs--;
|
|
if (!nr_running_ctxs && running_exclusive_ctxs)
|
|
running_exclusive_ctxs = false;
|
|
mutex_unlock(&damon_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* struct damon_system_ram_region - System RAM resource address region of
|
|
* [@start, @end).
|
|
* @start: Start address of the region (inclusive).
|
|
* @end: End address of the region (exclusive).
|
|
*/
|
|
struct damon_system_ram_region {
|
|
unsigned long start;
|
|
unsigned long end;
|
|
};
|
|
|
|
static int walk_system_ram(struct resource *res, void *arg)
|
|
{
|
|
struct damon_system_ram_region *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 damon_find_biggest_system_ram(unsigned long *start,
|
|
unsigned long *end)
|
|
|
|
{
|
|
struct damon_system_ram_region 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;
|
|
}
|
|
|
|
/**
|
|
* damon_set_region_biggest_system_ram_default() - Set the region of the given
|
|
* monitoring target as requested, or biggest 'System RAM'.
|
|
* @t: The monitoring target to set the region.
|
|
* @start: The pointer to the start address of the region.
|
|
* @end: The pointer to the end address of the region.
|
|
*
|
|
* This function sets the region of @t as requested by @start and @end. If the
|
|
* values of @start and @end are zero, however, this function finds the biggest
|
|
* 'System RAM' resource and sets the region to cover the resource. In the
|
|
* latter case, this function saves the start and end addresses of the resource
|
|
* in @start and @end, respectively.
|
|
*
|
|
* Return: 0 on success, negative error code otherwise.
|
|
*/
|
|
int damon_set_region_biggest_system_ram_default(struct damon_target *t,
|
|
unsigned long *start, unsigned long *end)
|
|
{
|
|
struct damon_addr_range addr_range;
|
|
|
|
if (*start > *end)
|
|
return -EINVAL;
|
|
|
|
if (!*start && !*end &&
|
|
!damon_find_biggest_system_ram(start, end))
|
|
return -EINVAL;
|
|
|
|
addr_range.start = *start;
|
|
addr_range.end = *end;
|
|
return damon_set_regions(t, &addr_range, 1);
|
|
}
|
|
|
|
/*
|
|
* damon_moving_sum() - Calculate an inferred moving sum value.
|
|
* @mvsum: Inferred sum of the last @len_window values.
|
|
* @nomvsum: Non-moving sum of the last discrete @len_window window values.
|
|
* @len_window: The number of last values to take care of.
|
|
* @new_value: New value that will be added to the pseudo moving sum.
|
|
*
|
|
* Moving sum (moving average * window size) is good for handling noise, but
|
|
* the cost of keeping past values can be high for arbitrary window size. This
|
|
* function implements a lightweight pseudo moving sum function that doesn't
|
|
* keep the past window values.
|
|
*
|
|
* It simply assumes there was no noise in the past, and get the no-noise
|
|
* assumed past value to drop from @nomvsum and @len_window. @nomvsum is a
|
|
* non-moving sum of the last window. For example, if @len_window is 10 and we
|
|
* have 25 values, @nomvsum is the sum of the 11th to 20th values of the 25
|
|
* values. Hence, this function simply drops @nomvsum / @len_window from
|
|
* given @mvsum and add @new_value.
|
|
*
|
|
* For example, if @len_window is 10 and @nomvsum is 50, the last 10 values for
|
|
* the last window could be vary, e.g., 0, 10, 0, 10, 0, 10, 0, 0, 0, 20. For
|
|
* calculating next moving sum with a new value, we should drop 0 from 50 and
|
|
* add the new value. However, this function assumes it got value 5 for each
|
|
* of the last ten times. Based on the assumption, when the next value is
|
|
* measured, it drops the assumed past value, 5 from the current sum, and add
|
|
* the new value to get the updated pseduo-moving average.
|
|
*
|
|
* This means the value could have errors, but the errors will be disappeared
|
|
* for every @len_window aligned calls. For example, if @len_window is 10, the
|
|
* pseudo moving sum with 11th value to 19th value would have an error. But
|
|
* the sum with 20th value will not have the error.
|
|
*
|
|
* Return: Pseudo-moving average after getting the @new_value.
|
|
*/
|
|
static unsigned int damon_moving_sum(unsigned int mvsum, unsigned int nomvsum,
|
|
unsigned int len_window, unsigned int new_value)
|
|
{
|
|
return mvsum - nomvsum / len_window + new_value;
|
|
}
|
|
|
|
/**
|
|
* damon_update_region_access_rate() - Update the access rate of a region.
|
|
* @r: The DAMON region to update for its access check result.
|
|
* @accessed: Whether the region has accessed during last sampling interval.
|
|
* @attrs: The damon_attrs of the DAMON context.
|
|
*
|
|
* Update the access rate of a region with the region's last sampling interval
|
|
* access check result.
|
|
*
|
|
* Usually this will be called by &damon_operations->check_accesses callback.
|
|
*/
|
|
void damon_update_region_access_rate(struct damon_region *r, bool accessed,
|
|
struct damon_attrs *attrs)
|
|
{
|
|
unsigned int len_window = 1;
|
|
|
|
/*
|
|
* sample_interval can be zero, but cannot be larger than
|
|
* aggr_interval, owing to validation of damon_set_attrs().
|
|
*/
|
|
if (attrs->sample_interval)
|
|
len_window = damon_max_nr_accesses(attrs);
|
|
r->nr_accesses_bp = damon_moving_sum(r->nr_accesses_bp,
|
|
r->last_nr_accesses * 10000, len_window,
|
|
accessed ? 10000 : 0);
|
|
|
|
if (accessed)
|
|
r->nr_accesses++;
|
|
}
|
|
|
|
static int __init damon_init(void)
|
|
{
|
|
damon_region_cache = KMEM_CACHE(damon_region, 0);
|
|
if (unlikely(!damon_region_cache)) {
|
|
pr_err("creating damon_region_cache fails\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
subsys_initcall(damon_init);
|
|
|
|
#include "tests/core-kunit.h"
|