| Message ID | 20211013144029.2154629-1-arnd@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/migrate: rework hotplug_memory_notifier() stub | expand |
On 13.10.21 16:39, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@arndb.de> > > The previous change added a compile time warning for the > CONFIG_MEMORY_HOTPLUG=n case: > > mm/migrate.c:3216:22: error: 'migrate_on_reclaim_callback' defined but not used [-Werror=unused-function] > 3216 | static int __meminit migrate_on_reclaim_callback(struct notifier_block *self, > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ > mm/migrate.c:3197:13: error: 'set_migration_target_nodes' defined but not used [-Werror=unused-function] > 3197 | static void set_migration_target_nodes(void) > | ^~~~~~~~~~~~~~~~~~~~~~~~~~ > > Rework the hotplug_memory_notifier() stub implementation into > an inline function so it always references its argument but > ignores it, leading the compiler to silently drop the hotplug > memory notifier function and further code referenced from it. > > To do this, the #ifdef around those functions need to be removed > as well, but this tends to help with readability and build coverage. > > Fixes: dd3e24b84bc1 ("mm/migrate: add CPU hotplug to demotion #ifdef") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > include/linux/memory.h | 5 ++++- > mm/migrate.c | 6 +----- > mm/page_ext.c | 4 +--- > mm/slab.c | 4 ++-- > 4 files changed, 8 insertions(+), 11 deletions(-) > > diff --git a/include/linux/memory.h b/include/linux/memory.h > index a216829df280..95af54f585a1 100644 > --- a/include/linux/memory.h > +++ b/include/linux/memory.h > @@ -125,7 +125,10 @@ static inline int memory_notify(unsigned long val, void *v) > { > return 0; > } > -#define hotplug_memory_notifier(fn, pri) ({ 0; }) > +static inline int hotplug_memory_notifier(notifier_fn_t fn, int pri) > +{ > + return 0; > +} > /* These aren't inline functions due to a GCC bug. */ > #define register_hotmemory_notifier(nb) ({ (void)(nb); 0; }) > #define unregister_hotmemory_notifier(nb) ({ (void)(nb); }) > diff --git a/mm/migrate.c b/mm/migrate.c > index 7769abac8aad..32303d517e10 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -3059,7 +3059,7 @@ void migrate_vma_finalize(struct migrate_vma *migrate) > EXPORT_SYMBOL(migrate_vma_finalize); > #endif /* CONFIG_DEVICE_PRIVATE */ > > -#if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_HOTPLUG_CPU) > +#if defined(CONFIG_HOTPLUG_CPU) > /* Disable reclaim-based migration. */ > static void __disable_all_migrate_targets(void) > { > @@ -3201,7 +3201,6 @@ static void set_migration_target_nodes(void) > put_online_mems(); > } > > -#if defined(CONFIG_MEMORY_HOTPLUG) > /* > * This leaves migrate-on-reclaim transiently disabled between > * the MEM_GOING_OFFLINE and MEM_OFFLINE events. This runs > @@ -3258,9 +3257,7 @@ static int __meminit migrate_on_reclaim_callback(struct notifier_block *self, > > return notifier_from_errno(0); > } > -#endif /* CONFIG_MEMORY_HOTPLUG */ > > -#ifdef CONFIG_HOTPLUG_CPU > /* > * React to hotplug events that might affect the migration targets > * like events that online or offline NUMA nodes. > @@ -3302,4 +3299,3 @@ static int __init migrate_on_reclaim_init(void) > } > late_initcall(migrate_on_reclaim_init); > #endif /* CONFIG_HOTPLUG_CPU */ > -#endif /* CONFIG_MEMORY_HOTPLUG || CONFIG_HOTPLUG_CPU */ > diff --git a/mm/page_ext.c b/mm/page_ext.c > index 106079e67c2e..6242afb24d84 100644 > --- a/mm/page_ext.c > +++ b/mm/page_ext.c > @@ -269,7 +269,7 @@ static int __meminit init_section_page_ext(unsigned long pfn, int nid) > total_usage += table_size; > return 0; > } > -#ifdef CONFIG_MEMORY_HOTPLUG > + > static void free_page_ext(void *addr) > { > if (is_vmalloc_addr(addr)) { > @@ -374,8 +374,6 @@ static int __meminit page_ext_callback(struct notifier_block *self, > return notifier_from_errno(ret); > } > > -#endif > - > void __init page_ext_init(void) > { > unsigned long pfn; > diff --git a/mm/slab.c b/mm/slab.c > index 01775fe0e002..da132a9ae6f8 100644 > --- a/mm/slab.c > +++ b/mm/slab.c > @@ -1095,7 +1095,7 @@ static int slab_offline_cpu(unsigned int cpu) > return 0; > } > > -#if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG) > +#if defined(CONFIG_NUMA) > /* > * Drains freelist for a node on each slab cache, used for memory hot-remove. > * Returns -EBUSY if all objects cannot be drained so that the node is not > @@ -1157,7 +1157,7 @@ static int __meminit slab_memory_callback(struct notifier_block *self, > out: > return notifier_from_errno(ret); > } > -#endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */ > +#endif /* CONFIG_NUMA */ > > /* > * swap the static kmem_cache_node with kmalloced memory > Acked-by: David Hildenbrand <david@redhat.com>
On Wed 13-10-21 16:39:38, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@arndb.de> > > The previous change added a compile time warning for the > CONFIG_MEMORY_HOTPLUG=n case: > > mm/migrate.c:3216:22: error: 'migrate_on_reclaim_callback' defined but not used [-Werror=unused-function] > 3216 | static int __meminit migrate_on_reclaim_callback(struct notifier_block *self, > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ > mm/migrate.c:3197:13: error: 'set_migration_target_nodes' defined but not used [-Werror=unused-function] > 3197 | static void set_migration_target_nodes(void) > | ^~~~~~~~~~~~~~~~~~~~~~~~~~ > > Rework the hotplug_memory_notifier() stub implementation into > an inline function so it always references its argument but > ignores it, leading the compiler to silently drop the hotplug > memory notifier function and further code referenced from it. > > To do this, the #ifdef around those functions need to be removed > as well, but this tends to help with readability and build coverage. > > Fixes: dd3e24b84bc1 ("mm/migrate: add CPU hotplug to demotion #ifdef") This is not a sha1 in the Linus tree. I suspect this comes from linux-next and akpm patch queue. Those sha1s are not stable so it is better to not reference them. Can we fold that into patch directly? > Signed-off-by: Arnd Bergmann <arnd@arndb.de> The fix looks good to me. Acked-by: Michal Hocko <mhocko@suse.com> Thanks! > --- > include/linux/memory.h | 5 ++++- > mm/migrate.c | 6 +----- > mm/page_ext.c | 4 +--- > mm/slab.c | 4 ++-- > 4 files changed, 8 insertions(+), 11 deletions(-) > > diff --git a/include/linux/memory.h b/include/linux/memory.h > index a216829df280..95af54f585a1 100644 > --- a/include/linux/memory.h > +++ b/include/linux/memory.h > @@ -125,7 +125,10 @@ static inline int memory_notify(unsigned long val, void *v) > { > return 0; > } > -#define hotplug_memory_notifier(fn, pri) ({ 0; }) > +static inline int hotplug_memory_notifier(notifier_fn_t fn, int pri) > +{ > + return 0; > +} > /* These aren't inline functions due to a GCC bug. */ > #define register_hotmemory_notifier(nb) ({ (void)(nb); 0; }) > #define unregister_hotmemory_notifier(nb) ({ (void)(nb); }) > diff --git a/mm/migrate.c b/mm/migrate.c > index 7769abac8aad..32303d517e10 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -3059,7 +3059,7 @@ void migrate_vma_finalize(struct migrate_vma *migrate) > EXPORT_SYMBOL(migrate_vma_finalize); > #endif /* CONFIG_DEVICE_PRIVATE */ > > -#if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_HOTPLUG_CPU) > +#if defined(CONFIG_HOTPLUG_CPU) > /* Disable reclaim-based migration. */ > static void __disable_all_migrate_targets(void) > { > @@ -3201,7 +3201,6 @@ static void set_migration_target_nodes(void) > put_online_mems(); > } > > -#if defined(CONFIG_MEMORY_HOTPLUG) > /* > * This leaves migrate-on-reclaim transiently disabled between > * the MEM_GOING_OFFLINE and MEM_OFFLINE events. This runs > @@ -3258,9 +3257,7 @@ static int __meminit migrate_on_reclaim_callback(struct notifier_block *self, > > return notifier_from_errno(0); > } > -#endif /* CONFIG_MEMORY_HOTPLUG */ > > -#ifdef CONFIG_HOTPLUG_CPU > /* > * React to hotplug events that might affect the migration targets > * like events that online or offline NUMA nodes. > @@ -3302,4 +3299,3 @@ static int __init migrate_on_reclaim_init(void) > } > late_initcall(migrate_on_reclaim_init); > #endif /* CONFIG_HOTPLUG_CPU */ > -#endif /* CONFIG_MEMORY_HOTPLUG || CONFIG_HOTPLUG_CPU */ > diff --git a/mm/page_ext.c b/mm/page_ext.c > index 106079e67c2e..6242afb24d84 100644 > --- a/mm/page_ext.c > +++ b/mm/page_ext.c > @@ -269,7 +269,7 @@ static int __meminit init_section_page_ext(unsigned long pfn, int nid) > total_usage += table_size; > return 0; > } > -#ifdef CONFIG_MEMORY_HOTPLUG > + > static void free_page_ext(void *addr) > { > if (is_vmalloc_addr(addr)) { > @@ -374,8 +374,6 @@ static int __meminit page_ext_callback(struct notifier_block *self, > return notifier_from_errno(ret); > } > > -#endif > - > void __init page_ext_init(void) > { > unsigned long pfn; > diff --git a/mm/slab.c b/mm/slab.c > index 01775fe0e002..da132a9ae6f8 100644 > --- a/mm/slab.c > +++ b/mm/slab.c > @@ -1095,7 +1095,7 @@ static int slab_offline_cpu(unsigned int cpu) > return 0; > } > > -#if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG) > +#if defined(CONFIG_NUMA) > /* > * Drains freelist for a node on each slab cache, used for memory hot-remove. > * Returns -EBUSY if all objects cannot be drained so that the node is not > @@ -1157,7 +1157,7 @@ static int __meminit slab_memory_callback(struct notifier_block *self, > out: > return notifier_from_errno(ret); > } > -#endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */ > +#endif /* CONFIG_NUMA */ > > /* > * swap the static kmem_cache_node with kmalloced memory > -- > 2.29.2
On 10/14/21 2:12 PM, Michal Hocko wrote: > On Wed 13-10-21 16:39:38, Arnd Bergmann wrote: >> From: Arnd Bergmann <arnd@arndb.de> >> >> The previous change added a compile time warning for the >> CONFIG_MEMORY_HOTPLUG=n case: >> >> mm/migrate.c:3216:22: error: 'migrate_on_reclaim_callback' defined but not used [-Werror=unused-function] >> 3216 | static int __meminit migrate_on_reclaim_callback(struct notifier_block *self, >> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ >> mm/migrate.c:3197:13: error: 'set_migration_target_nodes' defined but not used [-Werror=unused-function] >> 3197 | static void set_migration_target_nodes(void) >> | ^~~~~~~~~~~~~~~~~~~~~~~~~~ >> >> Rework the hotplug_memory_notifier() stub implementation into >> an inline function so it always references its argument but >> ignores it, leading the compiler to silently drop the hotplug >> memory notifier function and further code referenced from it. >> >> To do this, the #ifdef around those functions need to be removed >> as well, but this tends to help with readability and build coverage. >> >> Fixes: dd3e24b84bc1 ("mm/migrate: add CPU hotplug to demotion #ifdef") > > This is not a sha1 in the Linus tree. I suspect this comes from > linux-next and akpm patch queue. Those sha1s are not stable so it is > better to not reference them. I did not find this SHA on latest linux-next (20211015) as well. > > Can we fold that into patch directly? +1 > >> Signed-off-by: Arnd Bergmann <arnd@arndb.de> > > The fix looks good to me. > Acked-by: Michal Hocko <mhocko@suse.com> > Thanks! > >> --- >> include/linux/memory.h | 5 ++++- >> mm/migrate.c | 6 +----- >> mm/page_ext.c | 4 +--- >> mm/slab.c | 4 ++-- >> 4 files changed, 8 insertions(+), 11 deletions(-) >> >> diff --git a/include/linux/memory.h b/include/linux/memory.h >> index a216829df280..95af54f585a1 100644 >> --- a/include/linux/memory.h >> +++ b/include/linux/memory.h >> @@ -125,7 +125,10 @@ static inline int memory_notify(unsigned long val, void *v) >> { >> return 0; >> } >> -#define hotplug_memory_notifier(fn, pri) ({ 0; }) >> +static inline int hotplug_memory_notifier(notifier_fn_t fn, int pri) >> +{ >> + return 0; >> +} >> /* These aren't inline functions due to a GCC bug. */ >> #define register_hotmemory_notifier(nb) ({ (void)(nb); 0; }) >> #define unregister_hotmemory_notifier(nb) ({ (void)(nb); }) >> diff --git a/mm/migrate.c b/mm/migrate.c >> index 7769abac8aad..32303d517e10 100644 >> --- a/mm/migrate.c >> +++ b/mm/migrate.c >> @@ -3059,7 +3059,7 @@ void migrate_vma_finalize(struct migrate_vma *migrate) >> EXPORT_SYMBOL(migrate_vma_finalize); >> #endif /* CONFIG_DEVICE_PRIVATE */ >> >> -#if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_HOTPLUG_CPU) >> +#if defined(CONFIG_HOTPLUG_CPU) >> /* Disable reclaim-based migration. */ >> static void __disable_all_migrate_targets(void) >> { >> @@ -3201,7 +3201,6 @@ static void set_migration_target_nodes(void) >> put_online_mems(); >> } >> >> -#if defined(CONFIG_MEMORY_HOTPLUG) >> /* >> * This leaves migrate-on-reclaim transiently disabled between >> * the MEM_GOING_OFFLINE and MEM_OFFLINE events. This runs >> @@ -3258,9 +3257,7 @@ static int __meminit migrate_on_reclaim_callback(struct notifier_block *self, >> >> return notifier_from_errno(0); >> } >> -#endif /* CONFIG_MEMORY_HOTPLUG */ >> >> -#ifdef CONFIG_HOTPLUG_CPU >> /* >> * React to hotplug events that might affect the migration targets >> * like events that online or offline NUMA nodes. >> @@ -3302,4 +3299,3 @@ static int __init migrate_on_reclaim_init(void) >> } >> late_initcall(migrate_on_reclaim_init); >> #endif /* CONFIG_HOTPLUG_CPU */ >> -#endif /* CONFIG_MEMORY_HOTPLUG || CONFIG_HOTPLUG_CPU */ >> diff --git a/mm/page_ext.c b/mm/page_ext.c >> index 106079e67c2e..6242afb24d84 100644 >> --- a/mm/page_ext.c >> +++ b/mm/page_ext.c >> @@ -269,7 +269,7 @@ static int __meminit init_section_page_ext(unsigned long pfn, int nid) >> total_usage += table_size; >> return 0; >> } >> -#ifdef CONFIG_MEMORY_HOTPLUG >> + >> static void free_page_ext(void *addr) >> { >> if (is_vmalloc_addr(addr)) { >> @@ -374,8 +374,6 @@ static int __meminit page_ext_callback(struct notifier_block *self, >> return notifier_from_errno(ret); >> } >> >> -#endif >> - >> void __init page_ext_init(void) >> { >> unsigned long pfn; >> diff --git a/mm/slab.c b/mm/slab.c >> index 01775fe0e002..da132a9ae6f8 100644 >> --- a/mm/slab.c >> +++ b/mm/slab.c >> @@ -1095,7 +1095,7 @@ static int slab_offline_cpu(unsigned int cpu) >> return 0; >> } >> >> -#if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG) >> +#if defined(CONFIG_NUMA) >> /* >> * Drains freelist for a node on each slab cache, used for memory hot-remove. >> * Returns -EBUSY if all objects cannot be drained so that the node is not >> @@ -1157,7 +1157,7 @@ static int __meminit slab_memory_callback(struct notifier_block *self, >> out: >> return notifier_from_errno(ret); >> } >> -#endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */ >> +#endif /* CONFIG_NUMA */ >> >> /* >> * swap the static kmem_cache_node with kmalloced memory >> -- >> 2.29.2 >
diff --git a/include/linux/memory.h b/include/linux/memory.h index a216829df280..95af54f585a1 100644 --- a/include/linux/memory.h +++ b/include/linux/memory.h @@ -125,7 +125,10 @@ static inline int memory_notify(unsigned long val, void *v) { return 0; } -#define hotplug_memory_notifier(fn, pri) ({ 0; }) +static inline int hotplug_memory_notifier(notifier_fn_t fn, int pri) +{ + return 0; +} /* These aren't inline functions due to a GCC bug. */ #define register_hotmemory_notifier(nb) ({ (void)(nb); 0; }) #define unregister_hotmemory_notifier(nb) ({ (void)(nb); }) diff --git a/mm/migrate.c b/mm/migrate.c index 7769abac8aad..32303d517e10 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -3059,7 +3059,7 @@ void migrate_vma_finalize(struct migrate_vma *migrate) EXPORT_SYMBOL(migrate_vma_finalize); #endif /* CONFIG_DEVICE_PRIVATE */ -#if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_HOTPLUG_CPU) +#if defined(CONFIG_HOTPLUG_CPU) /* Disable reclaim-based migration. */ static void __disable_all_migrate_targets(void) { @@ -3201,7 +3201,6 @@ static void set_migration_target_nodes(void) put_online_mems(); } -#if defined(CONFIG_MEMORY_HOTPLUG) /* * This leaves migrate-on-reclaim transiently disabled between * the MEM_GOING_OFFLINE and MEM_OFFLINE events. This runs @@ -3258,9 +3257,7 @@ static int __meminit migrate_on_reclaim_callback(struct notifier_block *self, return notifier_from_errno(0); } -#endif /* CONFIG_MEMORY_HOTPLUG */ -#ifdef CONFIG_HOTPLUG_CPU /* * React to hotplug events that might affect the migration targets * like events that online or offline NUMA nodes. @@ -3302,4 +3299,3 @@ static int __init migrate_on_reclaim_init(void) } late_initcall(migrate_on_reclaim_init); #endif /* CONFIG_HOTPLUG_CPU */ -#endif /* CONFIG_MEMORY_HOTPLUG || CONFIG_HOTPLUG_CPU */ diff --git a/mm/page_ext.c b/mm/page_ext.c index 106079e67c2e..6242afb24d84 100644 --- a/mm/page_ext.c +++ b/mm/page_ext.c @@ -269,7 +269,7 @@ static int __meminit init_section_page_ext(unsigned long pfn, int nid) total_usage += table_size; return 0; } -#ifdef CONFIG_MEMORY_HOTPLUG + static void free_page_ext(void *addr) { if (is_vmalloc_addr(addr)) { @@ -374,8 +374,6 @@ static int __meminit page_ext_callback(struct notifier_block *self, return notifier_from_errno(ret); } -#endif - void __init page_ext_init(void) { unsigned long pfn; diff --git a/mm/slab.c b/mm/slab.c index 01775fe0e002..da132a9ae6f8 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -1095,7 +1095,7 @@ static int slab_offline_cpu(unsigned int cpu) return 0; } -#if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG) +#if defined(CONFIG_NUMA) /* * Drains freelist for a node on each slab cache, used for memory hot-remove. * Returns -EBUSY if all objects cannot be drained so that the node is not @@ -1157,7 +1157,7 @@ static int __meminit slab_memory_callback(struct notifier_block *self, out: return notifier_from_errno(ret); } -#endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */ +#endif /* CONFIG_NUMA */ /* * swap the static kmem_cache_node with kmalloced memory