From 52f238653e452e0fda61e880f263a173d219acd1 Mon Sep 17 00:00:00 2001 From: Suren Baghdasaryan Date: Mon, 27 Feb 2023 09:36:27 -0800 Subject: [PATCH] mm: introduce per-VMA lock statistics Add a new CONFIG_PER_VMA_LOCK_STATS config option to dump extra statistics about handling page fault under VMA lock. Link: https://lkml.kernel.org/r/20230227173632.3292573-29-surenb@google.com Signed-off-by: Suren Baghdasaryan Signed-off-by: Andrew Morton --- include/linux/vm_event_item.h | 6 ++++++ include/linux/vmstat.h | 6 ++++++ mm/Kconfig.debug | 6 ++++++ mm/memory.c | 2 ++ mm/vmstat.c | 6 ++++++ 5 files changed, 26 insertions(+) diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h index 7f5d1ca..8abfa12 100644 --- a/include/linux/vm_event_item.h +++ b/include/linux/vm_event_item.h @@ -150,6 +150,12 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, DIRECT_MAP_LEVEL2_SPLIT, DIRECT_MAP_LEVEL3_SPLIT, #endif +#ifdef CONFIG_PER_VMA_LOCK_STATS + VMA_LOCK_SUCCESS, + VMA_LOCK_ABORT, + VMA_LOCK_RETRY, + VMA_LOCK_MISS, +#endif NR_VM_EVENT_ITEMS }; diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h index 19cf5b6..fed855b 100644 --- a/include/linux/vmstat.h +++ b/include/linux/vmstat.h @@ -125,6 +125,12 @@ static inline void vm_events_fold_cpu(int cpu) #define count_vm_tlb_events(x, y) do { (void)(y); } while (0) #endif +#ifdef CONFIG_PER_VMA_LOCK_STATS +#define count_vm_vma_lock_event(x) count_vm_event(x) +#else +#define count_vm_vma_lock_event(x) do {} while (0) +#endif + #define __count_zid_vm_events(item, zid, delta) \ __count_vm_events(item##_NORMAL - ZONE_NORMAL + zid, delta) diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug index c3547a3..4965a73 100644 --- a/mm/Kconfig.debug +++ b/mm/Kconfig.debug @@ -279,3 +279,9 @@ config DEBUG_KMEMLEAK_AUTO_SCAN If unsure, say Y. +config PER_VMA_LOCK_STATS + bool "Statistics for per-vma locks" + depends on PER_VMA_LOCK + default y + help + Statistics for per-vma locks. diff --git a/mm/memory.c b/mm/memory.c index 55ac9cd..9999574 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5284,6 +5284,7 @@ retry: /* Check if the VMA got isolated after we found it */ if (vma->detached) { vma_end_read(vma); + count_vm_vma_lock_event(VMA_LOCK_MISS); /* The area was replaced with another one */ goto retry; } @@ -5292,6 +5293,7 @@ retry: return vma; inval: rcu_read_unlock(); + count_vm_vma_lock_event(VMA_LOCK_ABORT); return NULL; } #endif /* CONFIG_PER_VMA_LOCK */ diff --git a/mm/vmstat.c b/mm/vmstat.c index b730762..c280463 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -1399,6 +1399,12 @@ const char * const vmstat_text[] = { "direct_map_level2_splits", "direct_map_level3_splits", #endif +#ifdef CONFIG_PER_VMA_LOCK_STATS + "vma_lock_success", + "vma_lock_abort", + "vma_lock_retry", + "vma_lock_miss", +#endif #endif /* CONFIG_VM_EVENT_COUNTERS || CONFIG_MEMCG */ }; #endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA || CONFIG_MEMCG */ -- 2.7.4