On Tue, Jul 25, 2017 at 7:29 PM, Yubin Ruan <ablacktshirt@gmail.com> wrote:
2017-07-25 17:59 GMT+08:00 Rock Lee <rockdotlee@gmail.com>:
Hi,
I was using a program to test OOM killer, but OOM killer hung my board. The test snippet is very simple, just malloc() without free().
6 int i=0; 7 char *ptrtest=NULL; 8 while (1) 9 { 10 ptrtest = malloc(0x1000); 11 if (ptrtest == NULL) 12 printf("malloc failed.\n"); 13 } 14 return 0; 15
After I executed this program(a.out), there is no reaction of my shell. Only this messege was shown:
[ 180.138188] Out of memory: Kill process 2706 (qq) score 623 or sacrifice child [ 180.164230] Killed process 2706 (qq) total-vm:98156kB, anon-rss:96400kB, file-rss:4kB
I think it must be some problem with OOM killer, and tried a lot of way to get some infomation. And I got this:
======================================================= Process: a.out, cpu: 0 pid: 1463 start: 0xd5849b00 ===================================================== Task name: a.out pid: 1463 cpu: 0 state: 0x2 exit_state: 0x0 stack base: 0xd6190000 Stack: [<c08394e4>] __schedule+0x2c8 [<c018df88>] squashfs_cache_get+0x108 [<c0191020>] squashfs_readpage_block+0x28 [<c018f648>] squashfs_readpage+0x624 [<c0090d4c>] __do_page_cache_readahead+0x228 [<c00882f4>] filemap_fault+0x1d4 [<c00a5f10>] __do_fault+0x34 [<c00a8ab0>] do_read_fault+0x19c [<c00a9388>] handle_mm_fault+0x468 [<c00164b0>] do_page_fault+0x11c [<c00084a4>] do_PrefetchAbort+0x34 [<c0011c1c>] ret_from_exception+0x0
I am suprised, because a.out is in /tmp, there is no relation between a.out and squashfs(my rootfs). Could anyone give me a hint ? Is the problem of squashfs or OOM killer.
You say your rootfs is squashfs filesystem. Is /tmp using the same device and same filesystem (i.e., squashfs) ?
Not exactly, /tmp uses tmpfs, but my rootfs uses squashfs. -- Cheers, Rock