| Message ID | 20240607083711.62833-2-david@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/highmem: don't track highmem pages manually | expand |
On Fri, Jun 07, 2024 at 10:37:10AM +0200, David Hildenbrand wrote: >Can we get rid of the highmem ifdef in adjust_managed_page_count()? >Likely yes: we don't have that many totalhigh_pages() users, and they >all don't seem to be very performance critical. > >So let's implement totalhigh_pages() like nr_free_highpages(), >collecting information from all zones. This is now similar to what we do >in si_meminfo_node() to collect the per-node highmem page count. > >In the common case (single node, 3-4 zones), we really shouldn't care. >We could optimize a bit further (only walk ZONE_HIGHMEM and ZONE_MOVABLE >if required), but there doesn't seem a real need for that. > >Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> >--- > include/linux/highmem-internal.h | 9 ++------- > mm/highmem.c | 16 +++++++++++++--- > mm/page_alloc.c | 4 ---- > 3 files changed, 15 insertions(+), 14 deletions(-) > >diff --git a/include/linux/highmem-internal.h b/include/linux/highmem-internal.h >index a3028e400a9c6..65f865fbbac04 100644 >--- a/include/linux/highmem-internal.h >+++ b/include/linux/highmem-internal.h >@@ -132,7 +132,7 @@ static inline void __kunmap_atomic(const void *addr) > } > > unsigned int __nr_free_highpages(void); >-extern atomic_long_t _totalhigh_pages; >+unsigned long __totalhigh_pages(void); > > static inline unsigned int nr_free_highpages(void) > { >@@ -141,12 +141,7 @@ static inline unsigned int nr_free_highpages(void) > > static inline unsigned long totalhigh_pages(void) > { >- return (unsigned long)atomic_long_read(&_totalhigh_pages); >-} >- >-static inline void totalhigh_pages_add(long count) >-{ >- atomic_long_add(count, &_totalhigh_pages); >+ return __totalhigh_pages(); > } > > static inline bool is_kmap_addr(const void *x) >diff --git a/mm/highmem.c b/mm/highmem.c >index bd48ba445dd41..3c4e9f8c26dcd 100644 >--- a/mm/highmem.c >+++ b/mm/highmem.c >@@ -111,9 +111,6 @@ static inline wait_queue_head_t *get_pkmap_wait_queue_head(unsigned int color) > } > #endif > >-atomic_long_t _totalhigh_pages __read_mostly; >-EXPORT_SYMBOL(_totalhigh_pages); >- > unsigned int __nr_free_highpages(void) > { > struct zone *zone; >@@ -127,6 +124,19 @@ unsigned int __nr_free_highpages(void) > return pages; > } > >+unsigned long __totalhigh_pages(void) >+{ >+ unsigned long pages = 0; >+ struct zone *zone; >+ >+ for_each_populated_zone(zone) { >+ if (is_highmem(zone)) >+ pages += zone_managed_pages(zone); >+ } >+ >+ return pages; >+} >+ > static int pkmap_count[LAST_PKMAP]; > static __cacheline_aligned_in_smp DEFINE_SPINLOCK(kmap_lock); > >diff --git a/mm/page_alloc.c b/mm/page_alloc.c >index fc98082a9cf9c..2224965ada468 100644 >--- a/mm/page_alloc.c >+++ b/mm/page_alloc.c >@@ -5794,10 +5794,6 @@ void adjust_managed_page_count(struct page *page, long count) > { > atomic_long_add(count, &page_zone(page)->managed_pages); > totalram_pages_add(count); >-#ifdef CONFIG_HIGHMEM >- if (PageHighMem(page)) >- totalhigh_pages_add(count); >-#endif > } > EXPORT_SYMBOL(adjust_managed_page_count); > >-- >2.45.1
On Fri, Jun 07, 2024 at 10:37:10AM +0200, David Hildenbrand wrote: > Can we get rid of the highmem ifdef in adjust_managed_page_count()? > Likely yes: we don't have that many totalhigh_pages() users, and they > all don't seem to be very performance critical. > > So let's implement totalhigh_pages() like nr_free_highpages(), > collecting information from all zones. This is now similar to what we do > in si_meminfo_node() to collect the per-node highmem page count. > > In the common case (single node, 3-4 zones), we really shouldn't care. > We could optimize a bit further (only walk ZONE_HIGHMEM and ZONE_MOVABLE > if required), but there doesn't seem a real need for that. > > Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de>
diff --git a/include/linux/highmem-internal.h b/include/linux/highmem-internal.h index a3028e400a9c6..65f865fbbac04 100644 --- a/include/linux/highmem-internal.h +++ b/include/linux/highmem-internal.h @@ -132,7 +132,7 @@ static inline void __kunmap_atomic(const void *addr) } unsigned int __nr_free_highpages(void); -extern atomic_long_t _totalhigh_pages; +unsigned long __totalhigh_pages(void); static inline unsigned int nr_free_highpages(void) { @@ -141,12 +141,7 @@ static inline unsigned int nr_free_highpages(void) static inline unsigned long totalhigh_pages(void) { - return (unsigned long)atomic_long_read(&_totalhigh_pages); -} - -static inline void totalhigh_pages_add(long count) -{ - atomic_long_add(count, &_totalhigh_pages); + return __totalhigh_pages(); } static inline bool is_kmap_addr(const void *x) diff --git a/mm/highmem.c b/mm/highmem.c index bd48ba445dd41..3c4e9f8c26dcd 100644 --- a/mm/highmem.c +++ b/mm/highmem.c @@ -111,9 +111,6 @@ static inline wait_queue_head_t *get_pkmap_wait_queue_head(unsigned int color) } #endif -atomic_long_t _totalhigh_pages __read_mostly; -EXPORT_SYMBOL(_totalhigh_pages); - unsigned int __nr_free_highpages(void) { struct zone *zone; @@ -127,6 +124,19 @@ unsigned int __nr_free_highpages(void) return pages; } +unsigned long __totalhigh_pages(void) +{ + unsigned long pages = 0; + struct zone *zone; + + for_each_populated_zone(zone) { + if (is_highmem(zone)) + pages += zone_managed_pages(zone); + } + + return pages; +} + static int pkmap_count[LAST_PKMAP]; static __cacheline_aligned_in_smp DEFINE_SPINLOCK(kmap_lock); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index fc98082a9cf9c..2224965ada468 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5794,10 +5794,6 @@ void adjust_managed_page_count(struct page *page, long count) { atomic_long_add(count, &page_zone(page)->managed_pages); totalram_pages_add(count); -#ifdef CONFIG_HIGHMEM - if (PageHighMem(page)) - totalhigh_pages_add(count); -#endif } EXPORT_SYMBOL(adjust_managed_page_count);
Can we get rid of the highmem ifdef in adjust_managed_page_count()? Likely yes: we don't have that many totalhigh_pages() users, and they all don't seem to be very performance critical. So let's implement totalhigh_pages() like nr_free_highpages(), collecting information from all zones. This is now similar to what we do in si_meminfo_node() to collect the per-node highmem page count. In the common case (single node, 3-4 zones), we really shouldn't care. We could optimize a bit further (only walk ZONE_HIGHMEM and ZONE_MOVABLE if required), but there doesn't seem a real need for that. Signed-off-by: David Hildenbrand <david@redhat.com> --- include/linux/highmem-internal.h | 9 ++------- mm/highmem.c | 16 +++++++++++++--- mm/page_alloc.c | 4 ---- 3 files changed, 15 insertions(+), 14 deletions(-)