* [PATCH 1/1] mm: change per-VMA lock statistics to be disabled by default
@ 2023-04-28 17:35 Suren Baghdasaryan
2023-04-28 17:40 ` Lorenzo Stoakes
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Suren Baghdasaryan @ 2023-04-28 17:35 UTC (permalink / raw)
To: akpm
Cc: torvalds, lstoakes, vbabka, linux-mm, linux-kernel, kernel-team, surenb
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.
Fixes: 52f238653e45 ("mm: introduce per-VMA lock statistics")
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
---
mm/Kconfig.debug | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
index 6dae63b46368..a925415b4d10 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.
--
2.40.1.495.gc816e09b53d-goog
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH 1/1] mm: change per-VMA lock statistics to be disabled by default
2023-04-28 17:35 [PATCH 1/1] mm: change per-VMA lock statistics to be disabled by default Suren Baghdasaryan
@ 2023-04-28 17:40 ` Lorenzo Stoakes
2023-05-02 10:00 ` Vlastimil Babka
2023-05-02 11:27 ` David Hildenbrand
2 siblings, 0 replies; 4+ messages in thread
From: Lorenzo Stoakes @ 2023-04-28 17:40 UTC (permalink / raw)
To: Suren Baghdasaryan
Cc: akpm, torvalds, vbabka, linux-mm, linux-kernel, kernel-team
On Fri, Apr 28, 2023 at 10:35:33AM -0700, Suren Baghdasaryan wrote:
> 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.
>
> Fixes: 52f238653e45 ("mm: introduce per-VMA lock statistics")
> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
> Signed-off-by: Suren Baghdasaryan <surenb@google.com>
> ---
> mm/Kconfig.debug | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
> index 6dae63b46368..a925415b4d10 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.
> --
> 2.40.1.495.gc816e09b53d-goog
>
Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH 1/1] mm: change per-VMA lock statistics to be disabled by default
2023-04-28 17:35 [PATCH 1/1] mm: change per-VMA lock statistics to be disabled by default Suren Baghdasaryan
2023-04-28 17:40 ` Lorenzo Stoakes
@ 2023-05-02 10:00 ` Vlastimil Babka
2023-05-02 11:27 ` David Hildenbrand
2 siblings, 0 replies; 4+ messages in thread
From: Vlastimil Babka @ 2023-05-02 10:00 UTC (permalink / raw)
To: Suren Baghdasaryan, akpm
Cc: torvalds, lstoakes, linux-mm, linux-kernel, kernel-team
On 4/28/23 19:35, Suren Baghdasaryan wrote:
> 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.
>
> Fixes: 52f238653e45 ("mm: introduce per-VMA lock statistics")
> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
> Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
> ---
> mm/Kconfig.debug | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
> index 6dae63b46368..a925415b4d10 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.
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH 1/1] mm: change per-VMA lock statistics to be disabled by default
2023-04-28 17:35 [PATCH 1/1] mm: change per-VMA lock statistics to be disabled by default Suren Baghdasaryan
2023-04-28 17:40 ` Lorenzo Stoakes
2023-05-02 10:00 ` Vlastimil Babka
@ 2023-05-02 11:27 ` David Hildenbrand
2 siblings, 0 replies; 4+ messages in thread
From: David Hildenbrand @ 2023-05-02 11:27 UTC (permalink / raw)
To: Suren Baghdasaryan, akpm
Cc: torvalds, lstoakes, vbabka, linux-mm, linux-kernel, kernel-team
On 28.04.23 19:35, Suren Baghdasaryan wrote:
> 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.
>
> Fixes: 52f238653e45 ("mm: introduce per-VMA lock statistics")
> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
> Signed-off-by: Suren Baghdasaryan <surenb@google.com>
> ---
> mm/Kconfig.debug | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
> index 6dae63b46368..a925415b4d10 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.
Reviewed-by: David Hildenbrand <david@redhat.com>
--
Thanks,
David / dhildenb
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2023-05-02 17:39 UTC | newest]
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2023-04-28 17:35 [PATCH 1/1] mm: change per-VMA lock statistics to be disabled by default Suren Baghdasaryan
2023-04-28 17:40 ` Lorenzo Stoakes
2023-05-02 10:00 ` Vlastimil Babka
2023-05-02 11:27 ` David Hildenbrand
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