diff options
author | Joonsoo Kim <iamjoonsoo.kim@lge.com> | 2016-05-19 17:10:49 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-05-19 19:12:14 -0700 |
commit | 0139aa7b7fa12ceef095d99dc36606a5b10ab83a (patch) | |
tree | 94da74f2f79911a11a3c7c34f73ba971dec41a7e /include/linux/page_ref.h | |
parent | 6d061f9f6136d477932088c24ce155d7dc785746 (diff) | |
download | lwn-0139aa7b7fa12ceef095d99dc36606a5b10ab83a.tar.gz lwn-0139aa7b7fa12ceef095d99dc36606a5b10ab83a.zip |
mm: rename _count, field of the struct page, to _refcount
Many developers already know that field for reference count of the
struct page is _count and atomic type. They would try to handle it
directly and this could break the purpose of page reference count
tracepoint. To prevent direct _count modification, this patch rename it
to _refcount and add warning message on the code. After that, developer
who need to handle reference count will find that field should not be
accessed directly.
[akpm@linux-foundation.org: fix comments, per Vlastimil]
[akpm@linux-foundation.org: Documentation/vm/transhuge.txt too]
[sfr@canb.auug.org.au: sync ethernet driver changes]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Sunil Goutham <sgoutham@cavium.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Manish Chopra <manish.chopra@qlogic.com>
Cc: Yuval Mintz <yuval.mintz@qlogic.com>
Cc: Tariq Toukan <tariqt@mellanox.com>
Cc: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/page_ref.h')
-rw-r--r-- | include/linux/page_ref.h | 26 |
1 files changed, 13 insertions, 13 deletions
diff --git a/include/linux/page_ref.h b/include/linux/page_ref.h index e596d5d9540e..8b5e0a9f2431 100644 --- a/include/linux/page_ref.h +++ b/include/linux/page_ref.h @@ -63,17 +63,17 @@ static inline void __page_ref_unfreeze(struct page *page, int v) static inline int page_ref_count(struct page *page) { - return atomic_read(&page->_count); + return atomic_read(&page->_refcount); } static inline int page_count(struct page *page) { - return atomic_read(&compound_head(page)->_count); + return atomic_read(&compound_head(page)->_refcount); } static inline void set_page_count(struct page *page, int v) { - atomic_set(&page->_count, v); + atomic_set(&page->_refcount, v); if (page_ref_tracepoint_active(__tracepoint_page_ref_set)) __page_ref_set(page, v); } @@ -89,35 +89,35 @@ static inline void init_page_count(struct page *page) static inline void page_ref_add(struct page *page, int nr) { - atomic_add(nr, &page->_count); + atomic_add(nr, &page->_refcount); if (page_ref_tracepoint_active(__tracepoint_page_ref_mod)) __page_ref_mod(page, nr); } static inline void page_ref_sub(struct page *page, int nr) { - atomic_sub(nr, &page->_count); + atomic_sub(nr, &page->_refcount); if (page_ref_tracepoint_active(__tracepoint_page_ref_mod)) __page_ref_mod(page, -nr); } static inline void page_ref_inc(struct page *page) { - atomic_inc(&page->_count); + atomic_inc(&page->_refcount); if (page_ref_tracepoint_active(__tracepoint_page_ref_mod)) __page_ref_mod(page, 1); } static inline void page_ref_dec(struct page *page) { - atomic_dec(&page->_count); + atomic_dec(&page->_refcount); if (page_ref_tracepoint_active(__tracepoint_page_ref_mod)) __page_ref_mod(page, -1); } static inline int page_ref_sub_and_test(struct page *page, int nr) { - int ret = atomic_sub_and_test(nr, &page->_count); + int ret = atomic_sub_and_test(nr, &page->_refcount); if (page_ref_tracepoint_active(__tracepoint_page_ref_mod_and_test)) __page_ref_mod_and_test(page, -nr, ret); @@ -126,7 +126,7 @@ static inline int page_ref_sub_and_test(struct page *page, int nr) static inline int page_ref_dec_and_test(struct page *page) { - int ret = atomic_dec_and_test(&page->_count); + int ret = atomic_dec_and_test(&page->_refcount); if (page_ref_tracepoint_active(__tracepoint_page_ref_mod_and_test)) __page_ref_mod_and_test(page, -1, ret); @@ -135,7 +135,7 @@ static inline int page_ref_dec_and_test(struct page *page) static inline int page_ref_dec_return(struct page *page) { - int ret = atomic_dec_return(&page->_count); + int ret = atomic_dec_return(&page->_refcount); if (page_ref_tracepoint_active(__tracepoint_page_ref_mod_and_return)) __page_ref_mod_and_return(page, -1, ret); @@ -144,7 +144,7 @@ static inline int page_ref_dec_return(struct page *page) static inline int page_ref_add_unless(struct page *page, int nr, int u) { - int ret = atomic_add_unless(&page->_count, nr, u); + int ret = atomic_add_unless(&page->_refcount, nr, u); if (page_ref_tracepoint_active(__tracepoint_page_ref_mod_unless)) __page_ref_mod_unless(page, nr, ret); @@ -153,7 +153,7 @@ static inline int page_ref_add_unless(struct page *page, int nr, int u) static inline int page_ref_freeze(struct page *page, int count) { - int ret = likely(atomic_cmpxchg(&page->_count, count, 0) == count); + int ret = likely(atomic_cmpxchg(&page->_refcount, count, 0) == count); if (page_ref_tracepoint_active(__tracepoint_page_ref_freeze)) __page_ref_freeze(page, count, ret); @@ -165,7 +165,7 @@ static inline void page_ref_unfreeze(struct page *page, int count) VM_BUG_ON_PAGE(page_count(page) != 0, page); VM_BUG_ON(count == 0); - atomic_set(&page->_count, count); + atomic_set(&page->_refcount, count); if (page_ref_tracepoint_active(__tracepoint_page_ref_unfreeze)) __page_ref_unfreeze(page, count); } |