tools/memory-model: Label MP tests' producers and consumers

This commit adds comments that label the MP tests' producer and consumer
processes, and also that label the "exists" clause as the bad outcome.
Reported-by: NJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

tools/memory-model/litmus-tests/MP+fencewmbonceonce+fencermbonceonce.litmus

@@ -13,14 +13,14 @@ C MP+fencewmbonceonce+fencermbonceonce
 	int flag;
 }
 
-P0(int *buf, int *flag)
+P0(int *buf, int *flag) // Producer
 {
 	WRITE_ONCE(*buf, 1);
 	smp_wmb();
 	WRITE_ONCE(*flag, 1);
 }
 
-P1(int *buf, int *flag)
+P1(int *buf, int *flag) // Consumer
 {
 	int r0;
 	int r1;
@@ -30,4 +30,4 @@ P1(int *buf, int *flag)
 	r1 = READ_ONCE(*buf);
 }
 
-exists (1:r0=1 /\ 1:r1=0)
+exists (1:r0=1 /\ 1:r1=0) (* Bad outcome. *)

tools/memory-model/litmus-tests/MP+onceassign+derefonce.litmus

@@ -15,13 +15,13 @@ C MP+onceassign+derefonce
 	int y=0;
 }
 
-P0(int *x, int **p)
+P0(int *x, int **p) // Producer
 {
 	WRITE_ONCE(*x, 1);
 	rcu_assign_pointer(*p, x);
 }
 
-P1(int *x, int **p)
+P1(int *x, int **p) // Consumer
 {
 	int *r0;
 	int r1;
@@ -32,4 +32,4 @@ P1(int *x, int **p)
 	rcu_read_unlock();
 }
 
-exists (1:r0=x /\ 1:r1=0)
+exists (1:r0=x /\ 1:r1=0) (* Bad outcome. *)

tools/memory-model/litmus-tests/MP+polockmbonce+poacquiresilsil.litmus

@@ -15,7 +15,7 @@ C MP+polockmbonce+poacquiresilsil
 	int x;
 }
 
-P0(spinlock_t *lo, int *x)
+P0(spinlock_t *lo, int *x) // Producer
 {
 	spin_lock(lo);
 	smp_mb__after_spinlock();
@@ -23,7 +23,7 @@ P0(spinlock_t *lo, int *x)
 	spin_unlock(lo);
 }
 
-P1(spinlock_t *lo, int *x)
+P1(spinlock_t *lo, int *x) // Consumer
 {
 	int r1;
 	int r2;
@@ -34,4 +34,4 @@ P1(spinlock_t *lo, int *x)
 	r3 = spin_is_locked(lo);
 }
 
-exists (1:r1=1 /\ 1:r2=0 /\ 1:r3=1)
+exists (1:r1=1 /\ 1:r2=0 /\ 1:r3=1) (* Bad outcome. *)

tools/memory-model/litmus-tests/MP+polockonce+poacquiresilsil.litmus

@@ -15,14 +15,14 @@ C MP+polockonce+poacquiresilsil
 	int x;
 }
 
-P0(spinlock_t *lo, int *x)
+P0(spinlock_t *lo, int *x) // Producer
 {
 	spin_lock(lo);
 	WRITE_ONCE(*x, 1);
 	spin_unlock(lo);
 }
 
-P1(spinlock_t *lo, int *x)
+P1(spinlock_t *lo, int *x) // Consumer
 {
 	int r1;
 	int r2;
@@ -33,4 +33,4 @@ P1(spinlock_t *lo, int *x)
 	r3 = spin_is_locked(lo);
 }
 
-exists (1:r1=1 /\ 1:r2=0 /\ 1:r3=1)
+exists (1:r1=1 /\ 1:r2=0 /\ 1:r3=1) (* Bad outcome. *)

tools/memory-model/litmus-tests/MP+polocks.litmus

@@ -17,7 +17,7 @@ C MP+polocks
 	int flag;
 }
 
-P0(int *buf, int *flag, spinlock_t *mylock)
+P0(int *buf, int *flag, spinlock_t *mylock) // Producer
 {
 	WRITE_ONCE(*buf, 1);
 	spin_lock(mylock);
@@ -25,7 +25,7 @@ P0(int *buf, int *flag, spinlock_t *mylock)
 	spin_unlock(mylock);
 }
 
-P1(int *buf, int *flag, spinlock_t *mylock)
+P1(int *buf, int *flag, spinlock_t *mylock) // Consumer
 {
 	int r0;
 	int r1;
@@ -36,4 +36,4 @@ P1(int *buf, int *flag, spinlock_t *mylock)
 	r1 = READ_ONCE(*buf);
 }
 
-exists (1:r0=1 /\ 1:r1=0)
+exists (1:r0=1 /\ 1:r1=0) (* Bad outcome. *)

tools/memory-model/litmus-tests/MP+poonceonces.litmus

@@ -12,13 +12,13 @@ C MP+poonceonces
 	int flag;
 }
 
-P0(int *buf, int *flag)
+P0(int *buf, int *flag) // Producer
 {
 	WRITE_ONCE(*buf, 1);
 	WRITE_ONCE(*flag, 1);
 }
 
-P1(int *buf, int *flag)
+P1(int *buf, int *flag) // Consumer
 {
 	int r0;
 	int r1;
@@ -27,4 +27,4 @@ P1(int *buf, int *flag)
 	r1 = READ_ONCE(*buf);
 }
 
-exists (1:r0=1 /\ 1:r1=0)
+exists (1:r0=1 /\ 1:r1=0) (* Bad outcome. *)

tools/memory-model/litmus-tests/MP+pooncerelease+poacquireonce.litmus

@@ -13,13 +13,13 @@ C MP+pooncerelease+poacquireonce
 	int flag;
 }
 
-P0(int *buf, int *flag)
+P0(int *buf, int *flag) // Producer
 {
 	WRITE_ONCE(*buf, 1);
 	smp_store_release(flag, 1);
 }
 
-P1(int *buf, int *flag)
+P1(int *buf, int *flag) // Consumer
 {
 	int r0;
 	int r1;
@@ -28,4 +28,4 @@ P1(int *buf, int *flag)
 	r1 = READ_ONCE(*buf);
 }
 
-exists (1:r0=1 /\ 1:r1=0)
+exists (1:r0=1 /\ 1:r1=0) (* Bad outcome. *)

tools/memory-model/litmus-tests/MP+porevlocks.litmus

@@ -17,7 +17,7 @@ C MP+porevlocks
 	int flag;
 }
 
-P0(int *buf, int *flag, spinlock_t *mylock)
+P0(int *buf, int *flag, spinlock_t *mylock) // Consumer
 {
 	int r0;
 	int r1;
@@ -28,7 +28,7 @@ P0(int *buf, int *flag, spinlock_t *mylock)
 	spin_unlock(mylock);
 }
 
-P1(int *buf, int *flag, spinlock_t *mylock)
+P1(int *buf, int *flag, spinlock_t *mylock) // Producer
 {
 	spin_lock(mylock);
 	WRITE_ONCE(*buf, 1);
@@ -36,4 +36,4 @@ P1(int *buf, int *flag, spinlock_t *mylock)
 	WRITE_ONCE(*flag, 1);
 }
 
-exists (0:r0=1 /\ 0:r1=0)
+exists (0:r0=1 /\ 0:r1=0) (* Bad outcome. *)