On 2020-07-18 9:08 a.m., John David Anglin wrote: >>> diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S >>> index f05c9d5b6b9e..4ba43a3c7c67 100644 >>> --- a/arch/parisc/kernel/syscall.S >>> +++ b/arch/parisc/kernel/syscall.S >>> @@ -659,8 +678,15 @@ cas_action: >>> /* Error occurred on load or store */ >>> /* Free lock */ >>> #ifdef CONFIG_SMP >>> -98: LDCW 0(%sr2,%r20), %r1 /* Barrier */ >>> +98: sync /* Barrier */ >>> 99: ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP) >>> + nop >>> + nop >>> + nop >>> + nop >>> + nop >>> + nop >>> + nop >> I think you should put those nop's before the 99:ALTERNATIVE() instruction above. >> That way they all get replaced by one jump instead of multiple nops (when >> there is only one CPU in the SMP system). > Okay. I'll test. Thought the replacement was just nops. Do we know that a jump is faster than 8 nops? We need ALTERNATIVE conditions for the barrier defines. Dave -- John David Anglin dave.anglin@xxxxxxxx
