for_each_process_thread() is better, from 6.6, than

the older do_each|while_each_thread() macros

ch13/3_lockfree/thrdshowall_rcu/thrd_showall_rcu.c

@@ -80,7 +80,13 @@ static int showthrds_rcu(void)
 	 * the _rcu list-mutation primitives such as list_add_rcu() as long as it's
 	 * guarded by rcu_read_lock(). ...'
 	 */
+
+	/* Commit # 5ffd2c37cb7a53d520 ... */
+#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 6, 0)
 	do_each_thread(g, t) {     /* 'g' : process ptr; 't': thread ptr */
+#else
+	for_each_process_thread(g, t) {   /* 'g' : process ptr; 't': thread ptr */
+#endif
 		g_rcu = rcu_dereference(g);
 		t_rcu = rcu_dereference(t);
 
@@ -121,7 +127,11 @@ static int showthrds_rcu(void)
 		memset(buf, 0, sizeof(buf));
 		memset(tmp, 0, sizeof(tmp));
 		put_task_struct(t_rcu);	/* release reference to the task struct */
+#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 6, 0)
 	} while_each_thread(g, t);
+#else
+	}
+#endif
 	rcu_read_unlock();		/* This ends the RCU read-side critical section */
 	return total;
 }

ch13/4_lockdep/buggy_thrdshow_eg/thrd_showall_buggy.c

@@ -66,7 +66,12 @@ static int showthrds_buggy(void)
 	rcu_read_lock(); /* This triggers off an RCU read-side critical section; ensure
 			  * you are non-blocking within it! */
 #endif
+	/* Commit # 5ffd2c37cb7a53d520 ... */
+#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 6, 0)
 	do_each_thread(g, t) {     /* 'g' : process ptr; 't': thread ptr */
+#else
+	for_each_process_thread(g, t) {   /* 'g' : process ptr; 't': thread ptr */
+#endif
 		get_task_struct(t);	/* take a reference to the task struct */
 		task_lock(t);
 
@@ -107,7 +112,11 @@ static int showthrds_buggy(void)
 		memset(tmp, 0, sizeof(tmp));
 		task_unlock(t);
 		put_task_struct(t);	/* release reference to the task struct */
+#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 6, 0)
 	} while_each_thread(g, t);
+#else
+	}
+#endif
 #if 0
 	/* <same as above, reg the RCU synchronization for the task list> */
 	rcu_read_unlock();

ch6/foreach/thrd_showall/thrd_showall.c

@@ -88,7 +88,18 @@ static int showthrds(void)
 	 * Worry not, you'll learn several approaches to kernel synchronization in
 	 * the book's last two chapters.
 	 */
-	do_each_thread(p, t) {	/* 'p' : process ptr; 't': thread ptr */
+
+	/*
+	 * FYI, from 6.6, the do_ach_thread()/while_each_thread() style macros have been
+	 * removed in favor of the simpler and more readable for_each_process_thread()
+	 * macro.
+	 * Commit # 5ffd2c37cb7a53d520...
+	 */
+#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 6, 0)
+	do_each_thread(p, t) {     /* 'p' : process ptr; 't': thread ptr */
+#else
+	for_each_process_thread(p, t) {   /* 'p' : process ptr; 't': thread ptr */
+#endif
 		get_task_struct(t);	/* take a reference to the task struct */
 		task_lock(t);
 
@@ -129,7 +140,11 @@ static int showthrds(void)
 
 		task_unlock(t);
 		put_task_struct(t);	/* release reference to the task struct */
+#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 6, 0)
 	} while_each_thread(p, t);
+#else
+	}
+#endif
 
 	return total;
 }