| Message ID | 20230428173533.18158-1-surenb@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [1/1] mm: change per-VMA lock statistics to be disabled by default | expand |
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>
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.
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>
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.
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(-)