Messages in this thread | | | Date | Thu, 23 Jan 2020 16:56:15 +0000 | From | Will Deacon <> | Subject | Re: [PATCH -next] arm64/spinlock: fix a -Wunused-function warning |
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On Thu, Jan 23, 2020 at 11:29:45AM -0500, Qian Cai wrote: > The commit f5bfdc8e3947 ("locking/osq: Use optimized spinning loop for > arm64") introduced a warning from Clang because vcpu_is_preempted() is > compiled away, > > kernel/locking/osq_lock.c:25:19: warning: unused function 'node_cpu' > [-Wunused-function] > static inline int node_cpu(struct optimistic_spin_node *node) > ^ > 1 warning generated. > > Since vcpu_is_preempted() had already been defined in > include/linux/sched.h as false, just comment out the redundant macro, so > it can still be served for the documentation purpose. > > Fixes: f5bfdc8e3947 ("locking/osq: Use optimized spinning loop for arm64") > Signed-off-by: Qian Cai <cai@lca.pw> > --- > arch/arm64/include/asm/spinlock.h | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/spinlock.h b/arch/arm64/include/asm/spinlock.h > index 102404dc1e13..b05f82e8ba19 100644 > --- a/arch/arm64/include/asm/spinlock.h > +++ b/arch/arm64/include/asm/spinlock.h > @@ -17,7 +17,8 @@ > * > * See: > * https://lore.kernel.org/lkml/20200110100612.GC2827@hirez.programming.kicks-ass.net > + * > + * #define vcpu_is_preempted(cpu) false > */ > -#define vcpu_is_preempted(cpu) false
Damn, the whole point of this was to warn in the case that vcpu_is_preempted() does get defined for arm64. Can we force it to evaluate the macro argument instead (e.g. ({ (cpu), false; }) or something)?
Will
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