UPSTREAM: 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 <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

(cherry picked from commit 52f238653e452e0fda61e880f263a173d219acd1)

Bug: 161210518
Change-Id: I1bc9ab9bc0307af26e0c51ba12f9ad561af5b6c8
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
This commit is contained in:
Suren Baghdasaryan 2023-02-27 09:36:27 -08:00 committed by Carlos Llamas
parent 4e4c6989ae
commit ebbbcdfeaf
5 changed files with 27 additions and 0 deletions

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@ -146,6 +146,12 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
#ifdef CONFIG_X86 #ifdef CONFIG_X86
DIRECT_MAP_LEVEL2_SPLIT, DIRECT_MAP_LEVEL2_SPLIT,
DIRECT_MAP_LEVEL3_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 #endif
NR_VM_EVENT_ITEMS NR_VM_EVENT_ITEMS
}; };

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@ -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) #define count_vm_tlb_events(x, y) do { (void)(y); } while (0)
#endif #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) \ #define __count_zid_vm_events(item, zid, delta) \
__count_vm_events(item##_NORMAL - ZONE_NORMAL + zid, delta) __count_vm_events(item##_NORMAL - ZONE_NORMAL + zid, delta)

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@ -223,3 +223,10 @@ config PTDUMP_DEBUGFS
kernel. kernel.
If in doubt, say N. If in doubt, say N.
config PER_VMA_LOCK_STATS
bool "Statistics for per-vma locks"
depends on PER_VMA_LOCK
default y
help
Statistics for per-vma locks.

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@ -5314,6 +5314,7 @@ struct vm_area_struct *lock_vma_under_rcu(struct mm_struct *mm,
/* Check if the VMA got isolated after we found it */ /* Check if the VMA got isolated after we found it */
if (vma->detached) { if (vma->detached) {
vma_end_read(vma); vma_end_read(vma);
count_vm_vma_lock_event(VMA_LOCK_MISS);
/* The area was replaced with another one */ /* The area was replaced with another one */
goto retry; goto retry;
} }
@ -5322,6 +5323,7 @@ struct vm_area_struct *lock_vma_under_rcu(struct mm_struct *mm,
return vma; return vma;
inval: inval:
rcu_read_unlock(); rcu_read_unlock();
count_vm_vma_lock_event(VMA_LOCK_ABORT);
return NULL; return NULL;
} }
#endif /* CONFIG_PER_VMA_LOCK */ #endif /* CONFIG_PER_VMA_LOCK */

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@ -1394,6 +1394,12 @@ const char * const vmstat_text[] = {
"direct_map_level2_splits", "direct_map_level2_splits",
"direct_map_level3_splits", "direct_map_level3_splits",
#endif #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_VM_EVENT_COUNTERS || CONFIG_MEMCG */
}; };
#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA || CONFIG_MEMCG */ #endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA || CONFIG_MEMCG */