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author | Denys Vlasenko <dvlasenk@redhat.com> | 2016-03-17 21:18:24 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-17 22:09:34 (GMT) |
commit | 4b0f326163f09e6d67f09dd5e1a70093cee710fc (patch) | |
tree | 294056c36e6c0494b3c34580f8d169d20d4b2848 | |
parent | ee91ef6173e81819f5ff610c2485802081635657 (diff) | |
download | linux-4b0f326163f09e6d67f09dd5e1a70093cee710fc.tar.xz |
include/linux/page-flags.h: force inlining of selected page flag modifications
Sometimes gcc mysteriously doesn't inline
very small functions we expect to be inlined. See
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66122
With this .config:
http://busybox.net/~vda/kernel_config_OPTIMIZE_INLINING_and_Os,
the following functions get deinlined many times.
Examples of disassembly:
<SetPageUptodate> (43 copies, 141 calls):
55 push %rbp
48 89 e5 mov %rsp,%rbp
f0 80 0f 08 lock orb $0x8,(%rdi)
5d pop %rbp
c3 retq
<PagePrivate> (10 copies, 134 calls):
48 8b 07 mov (%rdi),%rax
55 push %rbp
48 89 e5 mov %rsp,%rbp
48 c1 e8 0b shr $0xb,%rax
83 e0 01 and $0x1,%eax
5d pop %rbp
c3 retq
This patch fixes this via s/inline/__always_inline/.
Code size decrease after the patch is ~7k:
text data bss dec hex filename
92125002 20826048 36417536 149368586 8e72f0a vmlinux
92118087 20826112 36417536 149361735 8e71447 vmlinux7_pageops_after
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | include/linux/page-flags.h | 30 |
1 files changed, 15 insertions, 15 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 5976955..f4ed4f1b 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -144,12 +144,12 @@ static inline struct page *compound_head(struct page *page) return page; } -static inline int PageTail(struct page *page) +static __always_inline int PageTail(struct page *page) { return READ_ONCE(page->compound_head) & 1; } -static inline int PageCompound(struct page *page) +static __always_inline int PageCompound(struct page *page) { return test_bit(PG_head, &page->flags) || PageTail(page); } @@ -184,31 +184,31 @@ static inline int PageCompound(struct page *page) * Macros to create function definitions for page flags */ #define TESTPAGEFLAG(uname, lname, policy) \ -static inline int Page##uname(struct page *page) \ +static __always_inline int Page##uname(struct page *page) \ { return test_bit(PG_##lname, &policy(page, 0)->flags); } #define SETPAGEFLAG(uname, lname, policy) \ -static inline void SetPage##uname(struct page *page) \ +static __always_inline void SetPage##uname(struct page *page) \ { set_bit(PG_##lname, &policy(page, 1)->flags); } #define CLEARPAGEFLAG(uname, lname, policy) \ -static inline void ClearPage##uname(struct page *page) \ +static __always_inline void ClearPage##uname(struct page *page) \ { clear_bit(PG_##lname, &policy(page, 1)->flags); } #define __SETPAGEFLAG(uname, lname, policy) \ -static inline void __SetPage##uname(struct page *page) \ +static __always_inline void __SetPage##uname(struct page *page) \ { __set_bit(PG_##lname, &policy(page, 1)->flags); } #define __CLEARPAGEFLAG(uname, lname, policy) \ -static inline void __ClearPage##uname(struct page *page) \ +static __always_inline void __ClearPage##uname(struct page *page) \ { __clear_bit(PG_##lname, &policy(page, 1)->flags); } #define TESTSETFLAG(uname, lname, policy) \ -static inline int TestSetPage##uname(struct page *page) \ +static __always_inline int TestSetPage##uname(struct page *page) \ { return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); } #define TESTCLEARFLAG(uname, lname, policy) \ -static inline int TestClearPage##uname(struct page *page) \ +static __always_inline int TestClearPage##uname(struct page *page) \ { return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); } #define PAGEFLAG(uname, lname, policy) \ @@ -371,7 +371,7 @@ PAGEFLAG(Idle, idle, PF_ANY) #define PAGE_MAPPING_KSM 2 #define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM) -static inline int PageAnon(struct page *page) +static __always_inline int PageAnon(struct page *page) { page = compound_head(page); return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0; @@ -384,7 +384,7 @@ static inline int PageAnon(struct page *page) * is found in VM_MERGEABLE vmas. It's a PageAnon page, pointing not to any * anon_vma, but to that page's node of the stable tree. */ -static inline int PageKsm(struct page *page) +static __always_inline int PageKsm(struct page *page) { page = compound_head(page); return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == @@ -415,14 +415,14 @@ static inline int PageUptodate(struct page *page) return ret; } -static inline void __SetPageUptodate(struct page *page) +static __always_inline void __SetPageUptodate(struct page *page) { VM_BUG_ON_PAGE(PageTail(page), page); smp_wmb(); __set_bit(PG_uptodate, &page->flags); } -static inline void SetPageUptodate(struct page *page) +static __always_inline void SetPageUptodate(struct page *page) { VM_BUG_ON_PAGE(PageTail(page), page); /* @@ -456,12 +456,12 @@ static inline void set_page_writeback_keepwrite(struct page *page) __PAGEFLAG(Head, head, PF_ANY) CLEARPAGEFLAG(Head, head, PF_ANY) -static inline void set_compound_head(struct page *page, struct page *head) +static __always_inline void set_compound_head(struct page *page, struct page *head) { WRITE_ONCE(page->compound_head, (unsigned long)head + 1); } -static inline void clear_compound_head(struct page *page) +static __always_inline void clear_compound_head(struct page *page) { WRITE_ONCE(page->compound_head, 0); } |