On 2016/3/22 22:47, Shakeel Butt wrote: > > On Tue, Mar 22, 2016 at 6:55 AM, Xishi Qiu <qiuxishi@xxxxxxxxxx <mailto:qiuxishi@xxxxxxxxxx>> wrote: > > [root@localhost c_test]# cat /proc/3948/smaps | grep Rss > > The /proc/[pid]/smaps read triggers the traversal of all of process's vmas and then page tables and accumulate RSS on each present page table entry. > > [root@localhost c_test]# cat /proc/3948/statm > 1042 173 154 1 0 48 0 > > The files /proc/[pid]/statm and /proc/[pid]/status uses the counters (MM_ANONPAGES & MM_FILEPAGES) in mm_struct to report RSS of a process. These counters are modified on page table modifications. However the kernel implements an optimization where each thread keeps a local copy of these counters in its task_struct. These local counter are accumulated in the shared counter of mm_struct after some number of page faults (I think 32) faced by the thread and thus there will be mismatch with smaps file. > > Shakeel Hi Shakeel, I malloc and memset 10M, then sleep. It seems that the problem is still exist, the kernel version is v4.1 [root@localhost c_test]# cat /proc/13746/statm 3603 2767 250 1 0 2609 0 [root@localhost c_test]# cat /proc/13746/smaps | grep Rss Rss: 4 kB Rss: 4 kB Rss: 4 kB Rss: 10244 kB Rss: 924 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: 8 kB Rss: 0 kB Rss: 4 kB Rss: 0 kB -- 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>