madvise LRU manipulation APIs need to scan address ranges to find present pages at page table and provides advice hints for them. Likewise pg[scan/steal] count on vmstat, madvise_pg[scanned/hinted] shows the proactive reclaim efficiency so this patch adds those two statistics in vmstat. madvise_pgscanned, madvise_pghinted Since proactive reclaim using process_madvise(2) as userland memory policy is popular(e.g,. Android ActivityManagerService), those stats are helpful to know how efficiently the policy works well. Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx> --- * From v1 - https://lore.kernel.org/linux-mm/20230117231632.2734737-1-minchan@xxxxxxxxxx/ * not relying on the pageout for accounting - mhocko * drop unnecessary changes - mhocko include/linux/vm_event_item.h | 2 ++ mm/madvise.c | 8 ++++++++ mm/vmstat.c | 2 ++ 3 files changed, 12 insertions(+) diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h index 7f5d1caf5890..3c117858946d 100644 --- a/include/linux/vm_event_item.h +++ b/include/linux/vm_event_item.h @@ -52,6 +52,8 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, PGSCAN_FILE, PGSTEAL_ANON, PGSTEAL_FILE, + MADVISE_PGSCANNED, + MADVISE_PGHINTED, #ifdef CONFIG_NUMA PGSCAN_ZONE_RECLAIM_FAILED, #endif diff --git a/mm/madvise.c b/mm/madvise.c index 7db6622f8293..d2624e77f729 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -344,6 +344,8 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, spinlock_t *ptl; struct folio *folio = NULL; LIST_HEAD(folio_list); + unsigned int nr_scanned = 0; + unsigned int nr_hinted = 0; bool pageout_anon_only_filter; if (fatal_signal_pending(current)) @@ -357,6 +359,7 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, pmd_t orig_pmd; unsigned long next = pmd_addr_end(addr, end); + nr_scanned += HPAGE_PMD_NR; tlb_change_page_size(tlb, HPAGE_PMD_SIZE); ptl = pmd_trans_huge_lock(pmd, vma); if (!ptl) @@ -414,6 +417,7 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, } } else folio_deactivate(folio); + nr_hinted += HPAGE_PMD_NR; huge_unlock: spin_unlock(ptl); if (pageout) @@ -431,6 +435,7 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, arch_enter_lazy_mmu_mode(); for (; addr < end; pte++, addr += PAGE_SIZE) { ptent = *pte; + nr_scanned++; if (pte_none(ptent)) continue; @@ -508,6 +513,7 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, } } else folio_deactivate(folio); + nr_hinted++; } arch_leave_lazy_mmu_mode(); @@ -515,6 +521,8 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, if (pageout) reclaim_pages(&folio_list); cond_resched(); + count_vm_events(MADVISE_PGSCANNED, nr_scanned); + count_vm_events(MADVISE_PGHINTED, nr_hinted); return 0; } diff --git a/mm/vmstat.c b/mm/vmstat.c index 1ea6a5ce1c41..84acc90820e1 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -1283,6 +1283,8 @@ const char * const vmstat_text[] = { "pgscan_file", "pgsteal_anon", "pgsteal_file", + "madvise_pgscanned", + "madvise_pghinted", #ifdef CONFIG_NUMA "zone_reclaim_failed", -- 2.39.1.405.gd4c25cc71f-goog
