Commit 52f23865 authored by Suren Baghdasaryan's avatar Suren Baghdasaryan Committed by Andrew Morton
Browse files

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: default avatarSuren Baghdasaryan <surenb@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 444eeb17

include/linux/vm_event_item.h

+6 −0
Original line number Diff line number Diff line
@@ -149,6 +149,12 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, 
#ifdef CONFIG_X86

		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

};

include/linux/vmstat.h

+6 −0
Original line number Diff line number Diff line
@@ -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)

mm/Kconfig.debug

+6 −0
Original line number Diff line number Diff line
@@ -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.

mm/memory.c

+2 −0
Original line number Diff line number Diff line
@@ -5284,6 +5284,7 @@ struct vm_area_struct *lock_vma_under_rcu(struct mm_struct *mm, 
	/* 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 @@ struct vm_area_struct *lock_vma_under_rcu(struct mm_struct *mm, 
	return vma;

inval:

	rcu_read_unlock();

	count_vm_vma_lock_event(VMA_LOCK_ABORT);

	return NULL;

}

#endif /* CONFIG_PER_VMA_LOCK */

mm/vmstat.c

+6 −0
Original line number Diff line number Diff line
@@ -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 */