diff --git a/Makefile b/Makefile
index 4906e16..35a280e 100644
--- a/Makefile
+++ b/Makefile
@@ -189,6 +189,7 @@ UPROGS=\
 	$U/_wc\
 	$U/_zombie\
 	$U/_trace\
+	$U/_sysinfotest\
 
 
 
diff --git a/kernel/defs.h b/kernel/defs.h
index a3c962b..4238154 100644
--- a/kernel/defs.h
+++ b/kernel/defs.h
@@ -63,6 +63,7 @@ void            ramdiskrw(struct buf*);
 void*           kalloc(void);
 void            kfree(void *);
 void            kinit(void);
+int             size_of_freemem(void);
 
 // log.c
 void            initlog(int, struct superblock*);
@@ -106,6 +107,7 @@ void            yield(void);
 int             either_copyout(int user_dst, uint64 dst, void *src, uint64 len);
 int             either_copyin(void *dst, int user_src, uint64 src, uint64 len);
 void            procdump(void);
+int             number_of_process(void);
 
 // swtch.S
 void            swtch(struct context*, struct context*);
diff --git a/kernel/kalloc.c b/kernel/kalloc.c
index 0699e7e..13ce5bc 100644
--- a/kernel/kalloc.c
+++ b/kernel/kalloc.c
@@ -80,3 +80,18 @@ kalloc(void)
     memset((char*)r, 5, PGSIZE); // fill with junk
   return (void*)r;
 }
+
+int
+size_of_freemem(void)
+{
+  struct run *r;
+  int count = 0;
+  acquire(&kmem.lock);
+  r = kmem.freelist;
+  while (r) {
+    count ++;
+    r = r->next;
+  }
+  release(&kmem.lock);
+  return count * PGSIZE;
+}
\ No newline at end of file
diff --git a/kernel/proc.c b/kernel/proc.c
index 00f2121..bb9b0e4 100644
--- a/kernel/proc.c
+++ b/kernel/proc.c
@@ -681,3 +681,14 @@ procdump(void)
     printf("\n");
   }
 }
+
+int
+number_of_process(void)
+{
+  struct proc *p;
+  int count = 0;
+  for (p = proc; p < &proc[NPROC]; p ++) {
+    if (p->state != UNUSED) count ++;
+  }
+  return count;
+}
\ No newline at end of file
diff --git a/kernel/syscall.c b/kernel/syscall.c
index 21ee02a..bb385ad 100644
--- a/kernel/syscall.c
+++ b/kernel/syscall.c
@@ -102,6 +102,7 @@ extern uint64 sys_link(void);
 extern uint64 sys_mkdir(void);
 extern uint64 sys_close(void);
 extern uint64 sys_trace(void);
+extern uint64 sys_sysinfo(void);
 
 // An array mapping syscall numbers from syscall.h
 // to the function that handles the system call.
@@ -128,6 +129,7 @@ static uint64 (*syscalls[])(void) = {
 [SYS_mkdir]   sys_mkdir,
 [SYS_close]   sys_close,
 [SYS_trace]   sys_trace,
+[SYS_sysinfo] sys_sysinfo,
 };
 
 char syscall_name[][8] = {
diff --git a/kernel/sysproc.c b/kernel/sysproc.c
index 2300f3b..a452fe7 100644
--- a/kernel/sysproc.c
+++ b/kernel/sysproc.c
@@ -5,6 +5,7 @@
 #include "memlayout.h"
 #include "spinlock.h"
 #include "proc.h"
+#include "sysinfo.h"
 
 uint64
 sys_exit(void)
@@ -101,4 +102,21 @@ sys_trace(void)
   myproc()->tracemask = mask;
   release(&myproc()->lock);
   return 0;
+}
+
+uint64
+sys_sysinfo(void)
+{
+  struct sysinfo info;
+  uint64 addr;
+  argaddr(0, &addr);
+  info.nproc = number_of_process();
+  info.freemem = size_of_freemem();
+  acquire(&myproc()->lock);
+  if(copyout(myproc()->pagetable, addr, (char *)&info, sizeof(info)) < 0){
+    release(&myproc()->lock);
+    return -1;
+  }
+  release(&myproc()->lock);
+  return 0;
 }
\ No newline at end of file
diff --git a/time.txt b/time.txt
new file mode 100644
index 0000000..e440e5c
--- /dev/null
+++ b/time.txt
@@ -0,0 +1 @@
+3
\ No newline at end of file
diff --git a/user/user.h b/user/user.h
index 0bf4333..14f69e5 100644
--- a/user/user.h
+++ b/user/user.h
@@ -1,4 +1,5 @@
 struct stat;
+struct sysinfo;
 
 // system calls
 int fork(void);
@@ -23,6 +24,7 @@ char* sbrk(int);
 int sleep(int);
 int uptime(void);
 int trace(int);
+int sysinfo(struct sysinfo*);
 
 // ulib.c
 int stat(const char*, struct stat*);
diff --git a/user/usys.pl b/user/usys.pl
index 9c97b05..bc109fd 100755
--- a/user/usys.pl
+++ b/user/usys.pl
@@ -37,3 +37,4 @@ entry("sbrk");
 entry("sleep");
 entry("uptime");
 entry("trace");
+entry("sysinfo");