136 lines
3.2 KiB
C
136 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Common Primitives for Data Access Monitoring
|
|
*
|
|
* Author: SeongJae Park <sj@kernel.org>
|
|
*/
|
|
|
|
#include <linux/mmu_notifier.h>
|
|
#include <linux/page_idle.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/rmap.h>
|
|
|
|
#include "ops-common.h"
|
|
|
|
/*
|
|
* Get an online page for a pfn if it's in the LRU list. Otherwise, returns
|
|
* NULL.
|
|
*
|
|
* The body of this function is stolen from the 'page_idle_get_page()'. We
|
|
* steal rather than reuse it because the code is quite simple.
|
|
*/
|
|
struct page *damon_get_page(unsigned long pfn)
|
|
{
|
|
struct page *page = pfn_to_online_page(pfn);
|
|
|
|
if (!page || !PageLRU(page) || !get_page_unless_zero(page))
|
|
return NULL;
|
|
|
|
if (unlikely(!PageLRU(page))) {
|
|
put_page(page);
|
|
page = NULL;
|
|
}
|
|
return page;
|
|
}
|
|
|
|
void damon_ptep_mkold(pte_t *pte, struct vm_area_struct *vma, unsigned long addr)
|
|
{
|
|
bool referenced = false;
|
|
struct page *page = damon_get_page(pte_pfn(*pte));
|
|
|
|
if (!page)
|
|
return;
|
|
|
|
if (ptep_test_and_clear_young(vma, addr, pte))
|
|
referenced = true;
|
|
|
|
#ifdef CONFIG_MMU_NOTIFIER
|
|
if (mmu_notifier_clear_young(vma->vm_mm, addr, addr + PAGE_SIZE))
|
|
referenced = true;
|
|
#endif /* CONFIG_MMU_NOTIFIER */
|
|
|
|
if (referenced)
|
|
set_page_young(page);
|
|
|
|
set_page_idle(page);
|
|
put_page(page);
|
|
}
|
|
|
|
void damon_pmdp_mkold(pmd_t *pmd, struct vm_area_struct *vma, unsigned long addr)
|
|
{
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
bool referenced = false;
|
|
struct page *page = damon_get_page(pmd_pfn(*pmd));
|
|
|
|
if (!page)
|
|
return;
|
|
|
|
if (pmdp_test_and_clear_young(vma, addr, pmd))
|
|
referenced = true;
|
|
|
|
#ifdef CONFIG_MMU_NOTIFIER
|
|
if (mmu_notifier_clear_young(vma->vm_mm, addr, addr + HPAGE_PMD_SIZE))
|
|
referenced = true;
|
|
#endif /* CONFIG_MMU_NOTIFIER */
|
|
|
|
if (referenced)
|
|
set_page_young(page);
|
|
|
|
set_page_idle(page);
|
|
put_page(page);
|
|
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
|
|
}
|
|
|
|
#define DAMON_MAX_SUBSCORE (100)
|
|
#define DAMON_MAX_AGE_IN_LOG (32)
|
|
|
|
int damon_hot_score(struct damon_ctx *c, struct damon_region *r,
|
|
struct damos *s)
|
|
{
|
|
int freq_subscore;
|
|
unsigned int age_in_sec;
|
|
int age_in_log, age_subscore;
|
|
unsigned int freq_weight = s->quota.weight_nr_accesses;
|
|
unsigned int age_weight = s->quota.weight_age;
|
|
int hotness;
|
|
|
|
freq_subscore = r->nr_accesses * DAMON_MAX_SUBSCORE /
|
|
damon_max_nr_accesses(&c->attrs);
|
|
|
|
age_in_sec = (unsigned long)r->age * c->attrs.aggr_interval / 1000000;
|
|
for (age_in_log = 0; age_in_log < DAMON_MAX_AGE_IN_LOG && age_in_sec;
|
|
age_in_log++, age_in_sec >>= 1)
|
|
;
|
|
|
|
/* If frequency is 0, higher age means it's colder */
|
|
if (freq_subscore == 0)
|
|
age_in_log *= -1;
|
|
|
|
/*
|
|
* Now age_in_log is in [-DAMON_MAX_AGE_IN_LOG, DAMON_MAX_AGE_IN_LOG].
|
|
* Scale it to be in [0, 100] and set it as age subscore.
|
|
*/
|
|
age_in_log += DAMON_MAX_AGE_IN_LOG;
|
|
age_subscore = age_in_log * DAMON_MAX_SUBSCORE /
|
|
DAMON_MAX_AGE_IN_LOG / 2;
|
|
|
|
hotness = (freq_weight * freq_subscore + age_weight * age_subscore);
|
|
if (freq_weight + age_weight)
|
|
hotness /= freq_weight + age_weight;
|
|
/*
|
|
* Transform it to fit in [0, DAMOS_MAX_SCORE]
|
|
*/
|
|
hotness = hotness * DAMOS_MAX_SCORE / DAMON_MAX_SUBSCORE;
|
|
|
|
return hotness;
|
|
}
|
|
|
|
int damon_cold_score(struct damon_ctx *c, struct damon_region *r,
|
|
struct damos *s)
|
|
{
|
|
int hotness = damon_hot_score(c, r, s);
|
|
|
|
/* Return coldness of the region */
|
|
return DAMOS_MAX_SCORE - hotness;
|
|
}
|