| Message ID | 20210321212501.2504947-1-slyfox@gentoo.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm: add page_owner_stack=off to make stack collection optional | expand |
On Sun, 21 Mar 2021 21:25:01 +0000 Sergei Trofimovich <slyfox@gentoo.org> wrote: > On some architectures (like ia64) stack walking is slow > and currently requires memory allocation. This causes stack > collection for page_owner=on to fall into recursion. > > This patch implements a page_owner_stack=off to allow page stats > collection. More user friendly alternative would be to have a GFP_ flag similar to __GFP_NOLOCKDEP which would allow us to skip the recursion. I'll prepare alternative patch. > Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org> > --- > .../admin-guide/kernel-parameters.txt | 6 +++++ > mm/Kconfig.debug | 3 ++- > mm/page_owner.c | 23 +++++++++++++------ > 3 files changed, 24 insertions(+), 8 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 04545725f187..3e710c4ab4df 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -3518,6 +3518,12 @@ > we can turn it on. > on: enable the feature > > + page_owner_stack= [KNL] Boot-time parameter option disabling stack > + collection of page allocation. Has effect only if > + "page_owner=on" is set. Useful for cases when stack > + collection is too slow or not feasible. > + off: disable the feature > + > page_poison= [KNL] Boot-time parameter changing the state of > poisoning on the buddy allocator, available with > CONFIG_PAGE_POISONING=y. > diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug > index 1e73717802f8..c1ecaf066c93 100644 > --- a/mm/Kconfig.debug > +++ b/mm/Kconfig.debug > @@ -57,7 +57,8 @@ config PAGE_OWNER > help to find bare alloc_page(s) leaks. Even if you include this > feature on your build, it is disabled in default. You should pass > "page_owner=on" to boot parameter in order to enable it. Eats > - a fair amount of memory if enabled. See tools/vm/page_owner_sort.c > + a fair amount of memory if enabled. Call chain tracking can be > + disabled with "page_owner_stack=off". See tools/vm/page_owner_sort.c > for user-space helper. > > If unsure, say N. > diff --git a/mm/page_owner.c b/mm/page_owner.c > index d15c7c4994f5..2cc1113fa28d 100644 > --- a/mm/page_owner.c > +++ b/mm/page_owner.c > @@ -31,6 +31,7 @@ struct page_owner { > }; > > static bool page_owner_enabled = false; > +static bool page_owner_stack_enabled = true; > DEFINE_STATIC_KEY_FALSE(page_owner_inited); > > static depot_stack_handle_t dummy_handle; > @@ -41,21 +42,26 @@ static void init_early_allocated_pages(void); > > static int __init early_page_owner_param(char *buf) > { > - if (!buf) > - return -EINVAL; > - > - if (strcmp(buf, "on") == 0) > - page_owner_enabled = true; > - > - return 0; > + return kstrtobool(buf, &page_owner_enabled); > } > early_param("page_owner", early_page_owner_param); > > +static int __init early_page_owner_stack_param(char *buf) > +{ > + return kstrtobool(buf, &page_owner_stack_enabled); > +} > +early_param("page_owner_stack", early_page_owner_stack_param); > + > static bool need_page_owner(void) > { > return page_owner_enabled; > } > > +static bool need_page_owner_stack(void) > +{ > + return page_owner_stack_enabled; > +} > + > static __always_inline depot_stack_handle_t create_dummy_stack(void) > { > unsigned long entries[4]; > @@ -122,6 +128,9 @@ static noinline depot_stack_handle_t save_stack(gfp_t flags) > depot_stack_handle_t handle; > unsigned int nr_entries; > > + if (!need_page_owner_stack()) > + return failure_handle; > + > nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 2); > > /* > -- > 2.31.0 >
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 04545725f187..3e710c4ab4df 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3518,6 +3518,12 @@ we can turn it on. on: enable the feature + page_owner_stack= [KNL] Boot-time parameter option disabling stack + collection of page allocation. Has effect only if + "page_owner=on" is set. Useful for cases when stack + collection is too slow or not feasible. + off: disable the feature + page_poison= [KNL] Boot-time parameter changing the state of poisoning on the buddy allocator, available with CONFIG_PAGE_POISONING=y. diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug index 1e73717802f8..c1ecaf066c93 100644 --- a/mm/Kconfig.debug +++ b/mm/Kconfig.debug @@ -57,7 +57,8 @@ config PAGE_OWNER help to find bare alloc_page(s) leaks. Even if you include this feature on your build, it is disabled in default. You should pass "page_owner=on" to boot parameter in order to enable it. Eats - a fair amount of memory if enabled. See tools/vm/page_owner_sort.c + a fair amount of memory if enabled. Call chain tracking can be + disabled with "page_owner_stack=off". See tools/vm/page_owner_sort.c for user-space helper. If unsure, say N. diff --git a/mm/page_owner.c b/mm/page_owner.c index d15c7c4994f5..2cc1113fa28d 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -31,6 +31,7 @@ struct page_owner { }; static bool page_owner_enabled = false; +static bool page_owner_stack_enabled = true; DEFINE_STATIC_KEY_FALSE(page_owner_inited); static depot_stack_handle_t dummy_handle; @@ -41,21 +42,26 @@ static void init_early_allocated_pages(void); static int __init early_page_owner_param(char *buf) { - if (!buf) - return -EINVAL; - - if (strcmp(buf, "on") == 0) - page_owner_enabled = true; - - return 0; + return kstrtobool(buf, &page_owner_enabled); } early_param("page_owner", early_page_owner_param); +static int __init early_page_owner_stack_param(char *buf) +{ + return kstrtobool(buf, &page_owner_stack_enabled); +} +early_param("page_owner_stack", early_page_owner_stack_param); + static bool need_page_owner(void) { return page_owner_enabled; } +static bool need_page_owner_stack(void) +{ + return page_owner_stack_enabled; +} + static __always_inline depot_stack_handle_t create_dummy_stack(void) { unsigned long entries[4]; @@ -122,6 +128,9 @@ static noinline depot_stack_handle_t save_stack(gfp_t flags) depot_stack_handle_t handle; unsigned int nr_entries; + if (!need_page_owner_stack()) + return failure_handle; + nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 2); /*
On some architectures (like ia64) stack walking is slow and currently requires memory allocation. This causes stack collection for page_owner=on to fall into recursion. This patch implements a page_owner_stack=off to allow page stats collection. Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org> --- .../admin-guide/kernel-parameters.txt | 6 +++++ mm/Kconfig.debug | 3 ++- mm/page_owner.c | 23 +++++++++++++------ 3 files changed, 24 insertions(+), 8 deletions(-)