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author | 2018-12-28 00:34:29 -0800 | |
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committer | 2018-12-28 12:11:47 -0800 | |
commit | ca79b0c211af63fa3276f0e3fd7dd9ada2439839 (patch) | |
tree | a9198e85582744619903c85349583bb453fe36cb /include/linux/highmem.h | |
parent | mm: convert zone->managed_pages to atomic variable (diff) | |
download | linux-ca79b0c211af63fa3276f0e3fd7dd9ada2439839.tar.gz linux-ca79b0c211af63fa3276f0e3fd7dd9ada2439839.tar.bz2 linux-ca79b0c211af63fa3276f0e3fd7dd9ada2439839.zip |
mm: convert totalram_pages and totalhigh_pages variables to atomic
totalram_pages and totalhigh_pages are made static inline function.
Main motivation was that managed_page_count_lock handling was complicating
things. It was discussed in length here,
https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes
better to remove the lock and convert variables to atomic, with preventing
poteintial store-to-read tearing as a bonus.
[akpm@linux-foundation.org: coding style fixes]
Link: http://lkml.kernel.org/r/1542090790-21750-4-git-send-email-arunks@codeaurora.org
Signed-off-by: Arun KS <arunks@codeaurora.org>
Suggested-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/highmem.h')
-rw-r--r-- | include/linux/highmem.h | 28 |
1 files changed, 26 insertions, 2 deletions
diff --git a/include/linux/highmem.h b/include/linux/highmem.h index 0690679832d4..ea5cdbd8c2c3 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -36,7 +36,31 @@ static inline void invalidate_kernel_vmap_range(void *vaddr, int size) /* declarations for linux/mm/highmem.c */ unsigned int nr_free_highpages(void); -extern unsigned long totalhigh_pages; +extern atomic_long_t _totalhigh_pages; +static inline unsigned long totalhigh_pages(void) +{ + return (unsigned long)atomic_long_read(&_totalhigh_pages); +} + +static inline void totalhigh_pages_inc(void) +{ + atomic_long_inc(&_totalhigh_pages); +} + +static inline void totalhigh_pages_dec(void) +{ + atomic_long_dec(&_totalhigh_pages); +} + +static inline void totalhigh_pages_add(long count) +{ + atomic_long_add(count, &_totalhigh_pages); +} + +static inline void totalhigh_pages_set(long val) +{ + atomic_long_set(&_totalhigh_pages, val); +} void kmap_flush_unused(void); @@ -51,7 +75,7 @@ static inline struct page *kmap_to_page(void *addr) return virt_to_page(addr); } -#define totalhigh_pages 0UL +static inline unsigned long totalhigh_pages(void) { return 0UL; } #ifndef ARCH_HAS_KMAP static inline void *kmap(struct page *page) |