Messages in this thread Patch in this message |  | | | Date | Fri, 3 Jul 2009 12:43:42 GMT | | From | tip-bot for Ingo Molnar <> | | Subject | [tip:perfcounters/urgent] x86: atomic64: Reduce size of functions |
Commit-ID: 3ac805d2afd3fa4a07cb5bcf352fd7fa83f28935 Gitweb: http://git.kernel.org/tip/3ac805d2afd3fa4a07cb5bcf352fd7fa83f28935 Author: Ingo Molnar <mingo@elte.hu> AuthorDate: Fri, 3 Jul 2009 12:51:19 +0200 Committer: Ingo Molnar <mingo@elte.hu> CommitDate: Fri, 3 Jul 2009 13:26:43 +0200
x86: atomic64: Reduce size of functions
cmpxchg8b is a huge instruction in terms of register footprint, we almost never want to inline it, not even within the same code module.
GCC 4.3 still messes up for two functions, under-judging the true cost of this instruction - so annotate two key functions to reduce the bloat:
arch/x86/lib/atomic64_32.o:
text data bss dec hex filename 1763 0 0 1763 6e3 atomic64_32.o.before 435 0 0 435 1b3 atomic64_32.o.after
Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> LKML-Reference: <alpine.LFD.2.01.0907021653030.3210@localhost.localdomain> Signed-off-by: Ingo Molnar <mingo@elte.hu>
--- arch/x86/lib/atomic64_32.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/lib/atomic64_32.c b/arch/x86/lib/atomic64_32.c index 6195962..a910238 100644 --- a/arch/x86/lib/atomic64_32.c +++ b/arch/x86/lib/atomic64_32.c @@ -4,7 +4,7 @@ #include <asm/cmpxchg.h> #include <asm/atomic.h> -static inline u64 cmpxchg8b(u64 *ptr, u64 old, u64 new) +static noinline u64 cmpxchg8b(u64 *ptr, u64 old, u64 new) { u32 low = new; u32 high = new >> 32; @@ -74,7 +74,7 @@ u64 atomic64_read(atomic64_t *ptr) * * Atomically adds @delta to @ptr and returns @delta + *@ptr */ -u64 atomic64_add_return(u64 delta, atomic64_t *ptr) +noinline u64 atomic64_add_return(u64 delta, atomic64_t *ptr) { /* * Try first with a (probably incorrect) assumption about
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