From 6152e53d9671b0ccc21c1bca842617b32ccfc5d8 Mon Sep 17 00:00:00 2001 From: Suren Baghdasaryan Date: Fri, 28 Apr 2023 10:35:33 -0700 Subject: [PATCH] mm: change per-VMA lock statistics to be disabled by default Change CONFIG_PER_VMA_LOCK_STATS to be disabled by default, as most users don't need it. Add configuration help to clarify its usage. Link: https://lkml.kernel.org/r/20230428173533.18158-1-surenb@google.com Fixes: 52f238653e45 ("mm: introduce per-VMA lock statistics") Signed-off-by: Suren Baghdasaryan Suggested-by: Linus Torvalds Reviewed-by: Lorenzo Stoakes Acked-by: Vlastimil Babka Reviewed-by: David Hildenbrand Signed-off-by: Andrew Morton --- mm/Kconfig.debug | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug index 6dae63b4..a925415 100644 --- a/mm/Kconfig.debug +++ b/mm/Kconfig.debug @@ -274,6 +274,12 @@ config DEBUG_KMEMLEAK_AUTO_SCAN config PER_VMA_LOCK_STATS bool "Statistics for per-vma locks" depends on PER_VMA_LOCK - default y help - Statistics for per-vma locks. + Say Y here to enable success, retry and failure counters of page + faults handled under protection of per-vma locks. When enabled, the + counters are exposed in /proc/vmstat. This information is useful for + kernel developers to evaluate effectiveness of per-vma locks and to + identify pathological cases. Counting these events introduces a small + overhead in the page fault path. + + If in doubt, say N. -- 2.7.4