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-rw-r--r--mm/damon/paddr.c351
1 files changed, 351 insertions, 0 deletions
diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
new file mode 100644
index 0000000000..909db25efb
--- /dev/null
+++ b/mm/damon/paddr.c
@@ -0,0 +1,351 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DAMON Primitives for The Physical Address Space
+ *
+ * Author: SeongJae Park <sj@kernel.org>
+ */
+
+#define pr_fmt(fmt) "damon-pa: " fmt
+
+#include <linux/mmu_notifier.h>
+#include <linux/page_idle.h>
+#include <linux/pagemap.h>
+#include <linux/rmap.h>
+#include <linux/swap.h>
+
+#include "../internal.h"
+#include "ops-common.h"
+
+static bool __damon_pa_mkold(struct folio *folio, struct vm_area_struct *vma,
+ unsigned long addr, void *arg)
+{
+ DEFINE_FOLIO_VMA_WALK(pvmw, folio, vma, addr, 0);
+
+ while (page_vma_mapped_walk(&pvmw)) {
+ addr = pvmw.address;
+ if (pvmw.pte)
+ damon_ptep_mkold(pvmw.pte, vma, addr);
+ else
+ damon_pmdp_mkold(pvmw.pmd, vma, addr);
+ }
+ return true;
+}
+
+static void damon_pa_mkold(unsigned long paddr)
+{
+ struct folio *folio = damon_get_folio(PHYS_PFN(paddr));
+ struct rmap_walk_control rwc = {
+ .rmap_one = __damon_pa_mkold,
+ .anon_lock = folio_lock_anon_vma_read,
+ };
+ bool need_lock;
+
+ if (!folio)
+ return;
+
+ if (!folio_mapped(folio) || !folio_raw_mapping(folio)) {
+ folio_set_idle(folio);
+ goto out;
+ }
+
+ need_lock = !folio_test_anon(folio) || folio_test_ksm(folio);
+ if (need_lock && !folio_trylock(folio))
+ goto out;
+
+ rmap_walk(folio, &rwc);
+
+ if (need_lock)
+ folio_unlock(folio);
+
+out:
+ folio_put(folio);
+}
+
+static void __damon_pa_prepare_access_check(struct damon_region *r)
+{
+ r->sampling_addr = damon_rand(r->ar.start, r->ar.end);
+
+ damon_pa_mkold(r->sampling_addr);
+}
+
+static void damon_pa_prepare_access_checks(struct damon_ctx *ctx)
+{
+ struct damon_target *t;
+ struct damon_region *r;
+
+ damon_for_each_target(t, ctx) {
+ damon_for_each_region(r, t)
+ __damon_pa_prepare_access_check(r);
+ }
+}
+
+static bool __damon_pa_young(struct folio *folio, struct vm_area_struct *vma,
+ unsigned long addr, void *arg)
+{
+ bool *accessed = arg;
+ DEFINE_FOLIO_VMA_WALK(pvmw, folio, vma, addr, 0);
+
+ *accessed = false;
+ while (page_vma_mapped_walk(&pvmw)) {
+ addr = pvmw.address;
+ if (pvmw.pte) {
+ *accessed = pte_young(ptep_get(pvmw.pte)) ||
+ !folio_test_idle(folio) ||
+ mmu_notifier_test_young(vma->vm_mm, addr);
+ } else {
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ *accessed = pmd_young(pmdp_get(pvmw.pmd)) ||
+ !folio_test_idle(folio) ||
+ mmu_notifier_test_young(vma->vm_mm, addr);
+#else
+ WARN_ON_ONCE(1);
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+ }
+ if (*accessed) {
+ page_vma_mapped_walk_done(&pvmw);
+ break;
+ }
+ }
+
+ /* If accessed, stop walking */
+ return *accessed == false;
+}
+
+static bool damon_pa_young(unsigned long paddr, unsigned long *folio_sz)
+{
+ struct folio *folio = damon_get_folio(PHYS_PFN(paddr));
+ bool accessed = false;
+ struct rmap_walk_control rwc = {
+ .arg = &accessed,
+ .rmap_one = __damon_pa_young,
+ .anon_lock = folio_lock_anon_vma_read,
+ };
+ bool need_lock;
+
+ if (!folio)
+ return false;
+
+ if (!folio_mapped(folio) || !folio_raw_mapping(folio)) {
+ if (folio_test_idle(folio))
+ accessed = false;
+ else
+ accessed = true;
+ goto out;
+ }
+
+ need_lock = !folio_test_anon(folio) || folio_test_ksm(folio);
+ if (need_lock && !folio_trylock(folio))
+ goto out;
+
+ rmap_walk(folio, &rwc);
+
+ if (need_lock)
+ folio_unlock(folio);
+
+out:
+ *folio_sz = folio_size(folio);
+ folio_put(folio);
+ return accessed;
+}
+
+static void __damon_pa_check_access(struct damon_region *r)
+{
+ static unsigned long last_addr;
+ static unsigned long last_folio_sz = PAGE_SIZE;
+ static bool last_accessed;
+
+ /* If the region is in the last checked page, reuse the result */
+ if (ALIGN_DOWN(last_addr, last_folio_sz) ==
+ ALIGN_DOWN(r->sampling_addr, last_folio_sz)) {
+ if (last_accessed)
+ r->nr_accesses++;
+ return;
+ }
+
+ last_accessed = damon_pa_young(r->sampling_addr, &last_folio_sz);
+ if (last_accessed)
+ r->nr_accesses++;
+
+ last_addr = r->sampling_addr;
+}
+
+static unsigned int damon_pa_check_accesses(struct damon_ctx *ctx)
+{
+ struct damon_target *t;
+ struct damon_region *r;
+ unsigned int max_nr_accesses = 0;
+
+ damon_for_each_target(t, ctx) {
+ damon_for_each_region(r, t) {
+ __damon_pa_check_access(r);
+ max_nr_accesses = max(r->nr_accesses, max_nr_accesses);
+ }
+ }
+
+ return max_nr_accesses;
+}
+
+static bool __damos_pa_filter_out(struct damos_filter *filter,
+ struct folio *folio)
+{
+ bool matched = false;
+ struct mem_cgroup *memcg;
+
+ switch (filter->type) {
+ case DAMOS_FILTER_TYPE_ANON:
+ matched = folio_test_anon(folio);
+ break;
+ case DAMOS_FILTER_TYPE_MEMCG:
+ rcu_read_lock();
+ memcg = folio_memcg_check(folio);
+ if (!memcg)
+ matched = false;
+ else
+ matched = filter->memcg_id == mem_cgroup_id(memcg);
+ rcu_read_unlock();
+ break;
+ default:
+ break;
+ }
+
+ return matched == filter->matching;
+}
+
+/*
+ * damos_pa_filter_out - Return true if the page should be filtered out.
+ */
+static bool damos_pa_filter_out(struct damos *scheme, struct folio *folio)
+{
+ struct damos_filter *filter;
+
+ damos_for_each_filter(filter, scheme) {
+ if (__damos_pa_filter_out(filter, folio))
+ return true;
+ }
+ return false;
+}
+
+static unsigned long damon_pa_pageout(struct damon_region *r, struct damos *s)
+{
+ unsigned long addr, applied;
+ LIST_HEAD(folio_list);
+
+ for (addr = r->ar.start; addr < r->ar.end; addr += PAGE_SIZE) {
+ struct folio *folio = damon_get_folio(PHYS_PFN(addr));
+
+ if (!folio)
+ continue;
+
+ if (damos_pa_filter_out(s, folio))
+ goto put_folio;
+
+ folio_clear_referenced(folio);
+ folio_test_clear_young(folio);
+ if (!folio_isolate_lru(folio))
+ goto put_folio;
+ if (folio_test_unevictable(folio))
+ folio_putback_lru(folio);
+ else
+ list_add(&folio->lru, &folio_list);
+put_folio:
+ folio_put(folio);
+ }
+ applied = reclaim_pages(&folio_list);
+ cond_resched();
+ return applied * PAGE_SIZE;
+}
+
+static inline unsigned long damon_pa_mark_accessed_or_deactivate(
+ struct damon_region *r, struct damos *s, bool mark_accessed)
+{
+ unsigned long addr, applied = 0;
+
+ for (addr = r->ar.start; addr < r->ar.end; addr += PAGE_SIZE) {
+ struct folio *folio = damon_get_folio(PHYS_PFN(addr));
+
+ if (!folio)
+ continue;
+
+ if (damos_pa_filter_out(s, folio))
+ goto put_folio;
+
+ if (mark_accessed)
+ folio_mark_accessed(folio);
+ else
+ folio_deactivate(folio);
+ applied += folio_nr_pages(folio);
+put_folio:
+ folio_put(folio);
+ }
+ return applied * PAGE_SIZE;
+}
+
+static unsigned long damon_pa_mark_accessed(struct damon_region *r,
+ struct damos *s)
+{
+ return damon_pa_mark_accessed_or_deactivate(r, s, true);
+}
+
+static unsigned long damon_pa_deactivate_pages(struct damon_region *r,
+ struct damos *s)
+{
+ return damon_pa_mark_accessed_or_deactivate(r, s, false);
+}
+
+static unsigned long damon_pa_apply_scheme(struct damon_ctx *ctx,
+ struct damon_target *t, struct damon_region *r,
+ struct damos *scheme)
+{
+ switch (scheme->action) {
+ case DAMOS_PAGEOUT:
+ return damon_pa_pageout(r, scheme);
+ case DAMOS_LRU_PRIO:
+ return damon_pa_mark_accessed(r, scheme);
+ case DAMOS_LRU_DEPRIO:
+ return damon_pa_deactivate_pages(r, scheme);
+ case DAMOS_STAT:
+ break;
+ default:
+ /* DAMOS actions that not yet supported by 'paddr'. */
+ break;
+ }
+ return 0;
+}
+
+static int damon_pa_scheme_score(struct damon_ctx *context,
+ struct damon_target *t, struct damon_region *r,
+ struct damos *scheme)
+{
+ switch (scheme->action) {
+ case DAMOS_PAGEOUT:
+ return damon_cold_score(context, r, scheme);
+ case DAMOS_LRU_PRIO:
+ return damon_hot_score(context, r, scheme);
+ case DAMOS_LRU_DEPRIO:
+ return damon_cold_score(context, r, scheme);
+ default:
+ break;
+ }
+
+ return DAMOS_MAX_SCORE;
+}
+
+static int __init damon_pa_initcall(void)
+{
+ struct damon_operations ops = {
+ .id = DAMON_OPS_PADDR,
+ .init = NULL,
+ .update = NULL,
+ .prepare_access_checks = damon_pa_prepare_access_checks,
+ .check_accesses = damon_pa_check_accesses,
+ .reset_aggregated = NULL,
+ .target_valid = NULL,
+ .cleanup = NULL,
+ .apply_scheme = damon_pa_apply_scheme,
+ .get_scheme_score = damon_pa_scheme_score,
+ };
+
+ return damon_register_ops(&ops);
+};
+
+subsys_initcall(damon_pa_initcall);