[root@localhost c_test]# cat /proc/3948/smaps | grep Rss Rss: 4 kB Rss: 4 kB Rss: 4 kB Rss: 796 kB Rss: 0 kB Rss: 16 kB Rss: 8 kB Rss: 12 kB Rss: 132 kB Rss: 12 kB Rss: 4 kB Rss: 4 kB Rss: 4 kB Rss: 4 kB Rss: 12 kB Rss: 0 kB Rss: 4 kB Rss: 0 kB [root@localhost c_test]# cat /proc/3948/statm 1042 173 154 1 0 48 0 173 means Rss is 173*4kb=692kb, right? so why it is different from the sum(1020kb) of "cat /proc/pid/smaps | grep Rss"? my test code is ... int main() { sleep(1000); return 0; } the kernel version is v4.1 Thanks, Xishi Qiu -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>