Re: [PATCH 1/2] lockdep: improve current->(hard|soft)irqs_enabled synchronisation with actual irq state

From: peterz
Date: Fri Aug 07 2020 - 07:13:39 EST



What's wrong with something like this?

AFAICT there's no reason to actually try and add IRQ tracing here, it's
just a hand full of instructions at the most.

---

diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index 3a0db7b0b46e..6be22c1838e2 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -196,33 +196,6 @@ static inline bool arch_irqs_disabled(void)
arch_local_irq_restore(flags); \
} while(0)

-#ifdef CONFIG_TRACE_IRQFLAGS
-#define powerpc_local_irq_pmu_save(flags) \
- do { \
- raw_local_irq_pmu_save(flags); \
- trace_hardirqs_off(); \
- } while(0)
-#define powerpc_local_irq_pmu_restore(flags) \
- do { \
- if (raw_irqs_disabled_flags(flags)) { \
- raw_local_irq_pmu_restore(flags); \
- trace_hardirqs_off(); \
- } else { \
- trace_hardirqs_on(); \
- raw_local_irq_pmu_restore(flags); \
- } \
- } while(0)
-#else
-#define powerpc_local_irq_pmu_save(flags) \
- do { \
- raw_local_irq_pmu_save(flags); \
- } while(0)
-#define powerpc_local_irq_pmu_restore(flags) \
- do { \
- raw_local_irq_pmu_restore(flags); \
- } while (0)
-#endif /* CONFIG_TRACE_IRQFLAGS */
-
#endif /* CONFIG_PPC_BOOK3S */

#ifdef CONFIG_PPC_BOOK3E
diff --git a/arch/powerpc/include/asm/local.h b/arch/powerpc/include/asm/local.h
index bc4bd19b7fc2..b357a35672b1 100644
--- a/arch/powerpc/include/asm/local.h
+++ b/arch/powerpc/include/asm/local.h
@@ -32,9 +32,9 @@ static __inline__ void local_##op(long i, local_t *l) \
{ \
unsigned long flags; \
\
- powerpc_local_irq_pmu_save(flags); \
+ raw_powerpc_local_irq_pmu_save(flags); \
l->v c_op i; \
- powerpc_local_irq_pmu_restore(flags); \
+ raw_powerpc_local_irq_pmu_restore(flags); \
}

#define LOCAL_OP_RETURN(op, c_op) \
@@ -43,9 +43,9 @@ static __inline__ long local_##op##_return(long a, local_t *l) \
long t; \
unsigned long flags; \
\
- powerpc_local_irq_pmu_save(flags); \
+ raw_powerpc_local_irq_pmu_save(flags); \
t = (l->v c_op a); \
- powerpc_local_irq_pmu_restore(flags); \
+ raw_powerpc_local_irq_pmu_restore(flags); \
\
return t; \
}
@@ -81,11 +81,11 @@ static __inline__ long local_cmpxchg(local_t *l, long o, long n)
long t;
unsigned long flags;

- powerpc_local_irq_pmu_save(flags);
+ raw_powerpc_local_irq_pmu_save(flags);
t = l->v;
if (t == o)
l->v = n;
- powerpc_local_irq_pmu_restore(flags);
+ raw_powerpc_local_irq_pmu_restore(flags);

return t;
}
@@ -95,10 +95,10 @@ static __inline__ long local_xchg(local_t *l, long n)
long t;
unsigned long flags;

- powerpc_local_irq_pmu_save(flags);
+ raw_powerpc_local_irq_pmu_save(flags);
t = l->v;
l->v = n;
- powerpc_local_irq_pmu_restore(flags);
+ raw_powerpc_local_irq_pmu_restore(flags);

return t;
}
@@ -117,12 +117,12 @@ static __inline__ int local_add_unless(local_t *l, long a, long u)
unsigned long flags;
int ret = 0;

- powerpc_local_irq_pmu_save(flags);
+ raw_powerpc_local_irq_pmu_save(flags);
if (l->v != u) {
l->v += a;
ret = 1;
}
- powerpc_local_irq_pmu_restore(flags);
+ raw_powerpc_local_irq_pmu_restore(flags);

return ret;
}