Currently THP allocation events data is fairly opaque, since you can only get it system-wide. This patch makes it easier to reason about transparent hugepage behaviour on a per-memcg basis.
For anonymous THP-backed pages, we already have MEMCG_RSS_HUGE in v1, which is used for v1's rss_huge [sic]. This is reused here as it's fairly involved to untangle NR_ANON_THPS right now to make it per-memcg, since right now some of this is delegated to rmap before we have any memcg actually assigned to the page. It's a good idea to rework that, but let's leave untangling THP allocation for a future patch. Signed-off-by: Chris Down <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Tejun Heo <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] --- Documentation/admin-guide/cgroup-v2.rst | 14 ++++++++++++++ mm/huge_memory.c | 2 ++ mm/khugepaged.c | 2 ++ mm/memcontrol.c | 13 +++++++++++++ 4 files changed, 31 insertions(+) diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 7bf3f129c68b..b6989b39ed8e 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -1189,6 +1189,10 @@ PAGE_SIZE multiple when read back. Amount of cached filesystem data that was modified and is currently being written back to disk + anon_thp + Amount of memory used in anonymous mappings backed by + transparent hugepages + inactive_anon, active_anon, inactive_file, active_file, unevictable Amount of memory, swap-backed and filesystem-backed, on the internal memory management lists used by the @@ -1248,6 +1252,16 @@ PAGE_SIZE multiple when read back. Amount of reclaimed lazyfree pages + thp_fault_alloc + + Number of transparent hugepages which were allocated to satisfy + a page fault, including COW faults + + thp_collapse_alloc + + Number of transparent hugepages which were allocated to + allow collapsing an existing range of pages + memory.swap.current A read-only single value file which exists on non-root cgroups. diff --git a/mm/huge_memory.c b/mm/huge_memory.c index f5f1d4324fe2..6cb7a748aa33 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -617,6 +617,7 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf, mm_inc_nr_ptes(vma->vm_mm); spin_unlock(vmf->ptl); count_vm_event(THP_FAULT_ALLOC); + count_memcg_events(memcg, THP_FAULT_ALLOC, 1); } return 0; @@ -1339,6 +1340,7 @@ vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd) } count_vm_event(THP_FAULT_ALLOC); + count_memcg_events(memcg, THP_FAULT_ALLOC, 1); if (!page) clear_huge_page(new_page, vmf->address, HPAGE_PMD_NR); diff --git a/mm/khugepaged.c b/mm/khugepaged.c index ceb242ca6ef6..54f3d33f897a 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1075,6 +1075,7 @@ static void collapse_huge_page(struct mm_struct *mm, BUG_ON(!pmd_none(*pmd)); page_add_new_anon_rmap(new_page, vma, address, true); mem_cgroup_commit_charge(new_page, memcg, false, true); + count_memcg_events(memcg, THP_COLLAPSE_ALLOC, 1); lru_cache_add_active_or_unevictable(new_page, vma); pgtable_trans_huge_deposit(mm, pmd, pgtable); set_pmd_at(mm, address, pmd, _pmd); @@ -1503,6 +1504,7 @@ static void collapse_shmem(struct mm_struct *mm, page_ref_add(new_page, HPAGE_PMD_NR - 1); set_page_dirty(new_page); mem_cgroup_commit_charge(new_page, memcg, false, true); + count_memcg_events(memcg, THP_COLLAPSE_ALLOC, 1); lru_cache_add_anon(new_page); /* diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 18f4aefbe0bf..2f4fe2fb9046 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5603,6 +5603,15 @@ static int memory_stat_show(struct seq_file *m, void *v) seq_printf(m, "file_writeback %llu\n", (u64)acc.stat[NR_WRITEBACK] * PAGE_SIZE); + /* + * TODO: We should eventually replace our own MEMCG_RSS_HUGE counter + * with the NR_ANON_THP vm counter, but right now it's a pain in the + * arse because it requires migrating the work out of rmap to a place + * where the page->mem_cgroup is set up and stable. + */ + seq_printf(m, "anon_thp %llu\n", + (u64)acc.stat[MEMCG_RSS_HUGE] * PAGE_SIZE); + for (i = 0; i < NR_LRU_LISTS; i++) seq_printf(m, "%s %llu\n", mem_cgroup_lru_names[i], (u64)acc.lru_pages[i] * PAGE_SIZE); @@ -5634,6 +5643,10 @@ static int memory_stat_show(struct seq_file *m, void *v) seq_printf(m, "pglazyfree %lu\n", acc.events[PGLAZYFREE]); seq_printf(m, "pglazyfreed %lu\n", acc.events[PGLAZYFREED]); + seq_printf(m, "thp_fault_alloc %lu\n", acc.events[THP_FAULT_ALLOC]); + seq_printf(m, "thp_collapse_alloc %lu\n", + acc.events[THP_COLLAPSE_ALLOC]); + return 0; } -- 2.20.1
