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The generated code improves from: 3da: 31 c0 xor %eax,%eax 3dc: f0 48 0f b1 8a 38 01 lock cmpxchg %rcx,0x138(%rdx) 3e3: 00 00 3e5: 48 85 c0 test %rax,%rax 3e8: 48 0f 44 c1 cmove %rcx,%rax to: 3da: 31 c0 xor %eax,%eax 3dc: f0 48 0f b1 8a 38 01 lock cmpxchg %rcx,0x138(%rdx) 3e3: 00 00 3e5: 48 0f 44 c1 cmove %rcx,%rax Signed-off-by: Uros Bizjak Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Darren Hart Cc: Davidlohr Bueso Cc: "André Almeida" --- kernel/futex/core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/futex/core.c b/kernel/futex/core.c index 3146730e55f7..11795439efb7 100644 --- a/kernel/futex/core.c +++ b/kernel/futex/core.c @@ -185,8 +185,9 @@ static u64 get_inode_sequence_number(struct inode *inode) if (WARN_ON_ONCE(!new)) continue; - old = atomic64_cmpxchg_relaxed(&inode->i_sequence, 0, new); - if (old) + old = 0; + if (!atomic64_try_cmpxchg_relaxed(&inode->i_sequence, + &old, new)) return old; return new; } -- 2.46.2