diff -Naur 0/linux/init/main.c 4/linux/init/main.c
--- 0/linux/init/main.c	2016-08-08 09:40:13.000000000 +0800
+++ 4/linux/init/main.c	2021-07-06 14:16:56.000000000 +0800
@@ -208,3 +208,9 @@
 	}
 	_exit(0);	/* NOTE! _exit, not exit() */
 }
+
+void print_nr(int sid)
+{
+	if (sid > 86)
+		printk(" --syscall: sid=%d, pid=%d\n", sid, current->pid);
+}
diff -Naur 0/linux/kernel/system_call.s 4/linux/kernel/system_call.s
--- 0/linux/kernel/system_call.s	2015-09-03 20:21:09.000000000 +0800
+++ 4/linux/kernel/system_call.s	2021-07-06 14:18:56.000000000 +0800
@@ -91,6 +91,11 @@
 	mov %dx,%es
 	movl $0x17,%edx		# fs points to local data space
 	mov %dx,%fs
+
+	pushl %eax   #by wyj
+	call print_nr
+	popl %eax
+
 	call sys_call_table(,%eax,4)
 	pushl %eax
 	movl current,%eax
diff -Naur 0/linux/mm/memory.c 4/linux/mm/memory.c
--- 0/linux/mm/memory.c	2015-09-04 15:24:20.000000000 +0800
+++ 4/linux/mm/memory.c	2021-07-06 14:21:45.000000000 +0800
@@ -370,6 +370,9 @@
 	unsigned long page;
 	int block,i;
 
+	if (current->pid > 5)
+		printk(" --do_no_page: address=%x, pid=%d\n", address, current->pid);
+		
 	address &= 0xfffff000;
 	tmp = address - current->start_code;
 	if (!current->executable || tmp >= current->end_data) {