Messages in this thread Patch in this message | | | From | Bang Li <> | Subject | [PATCH] ARC: remove redundant READ_ONCE() in cmpxchg loop | Date | Sat, 19 Mar 2022 10:03:16 +0800 |
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This patch reverts commit 7082a29c22ac ("ARC: use ACCESS_ONCE in cmpxchg loop").
It is not necessary to use READ_ONCE() because cmpxchg contains barrier. We can get it from commit d57f727264f1 ("ARC: add compiler barrier to LLSC based cmpxchg").
Signed-off-by: Bang Li <libang.linuxer@gmail.com> --- arch/arc/kernel/smp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arc/kernel/smp.c b/arch/arc/kernel/smp.c index 78e6d069b1c1..56c23f3e1309 100644 --- a/arch/arc/kernel/smp.c +++ b/arch/arc/kernel/smp.c @@ -274,7 +274,7 @@ static void ipi_send_msg_one(int cpu, enum ipi_msg_type msg) * and read back old value */ do { - new = old = READ_ONCE(*ipi_data_ptr); + new = old = *ipi_data_ptr; new |= 1U << msg; } while (cmpxchg(ipi_data_ptr, old, new) != old); -- 2.25.1
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