1713 2011-11-02 17:37:27 +0000 [NAS] Oprofile will cause kernel hang when profiling. 2012-08-16 21:00:21 +0000 1 1 7 Build System, Metadata & Runtime BSPs bsps-runtime unspecified Blacksand x86 RESOLVED WONTFIX (P3) Medium normal 1.3 1 shane.wang lianhao.lu alexandru.c.georgescu dvhart jessica.zhang lianhao.lu meta.mr.watcher meta.watcher poky.adt.watcher poky.watcher yp.kernel.watcher yp.watcher --- --- --- oldest_to_newest 17047 0 shane.wang 2011-11-02 17:37:27 +0000 During the profiling of NAS we implemented, when copying a big file (say 4GB) from the NAS samba server with ADT Oprofile plug-in, the NAS kernel will hang mostly. But without Oprofile, the issue disappears. 17051 1 jessica.zhang 2011-11-02 18:27:53 +0000 So what's the symptom of kernel hang, and core dump file? By the way, have you tried just with oprofile-viewer and oprofile-server instead of through eclipse plug-in, does it hang as well? "But without Oprofile, the issue disappears", what exactly does this mean, you stop oprofile-server or not doing oprofile at all? I have a feeling it may not related to ADT but Oprofile itself. 17052 2 lianhao.lu 2011-11-02 18:43:05 +0000 It's should be a bug in oprofile itself, not ADT. By saying "But without Oprofile, the issue disappears", it means doing the copy operation without oprofile at all. In most cases, the NAS just hang silently without any core dump or any out output on the screen. How ever we noticed a kernel panic once and by reading the panic output on the screen, we found an oprofile related function in kernel named something like "xxx_oprofile_add_sample_xxx" was in the call stack back trace. 17060 3 shane.wang 2011-11-02 20:40:56 +0000 The procedures to reproduce are: $opcontrol --start-daemon --separate=lib -c 6 $opcontrol --start Then on a client, copying a 4GB file from NAS, NAS system will hang. Without Oprofile, the error has never happened. 17082 4 dvhart 2011-11-03 15:58:20 +0000 Please provide the text of the kernel panic. 17086 5 lianhao.lu 2011-11-03 20:19:01 +0000 It seems we can no longer reproduce the kernel panic, but the system just hang silently without any output on screen. Here is a script which could trigger the hang on NAS/blacksand: #!/bin/sh opcontrol --init opcontrol --start-daemon --no-vmlinux --separate=lib -c 6 opcontrol --start rm -f testfile dd if=/dev/zero of=./testfile bs=1G count=4 17101 6 dvhart 2011-11-04 05:45:33 +0000 How long do you allow the command to run? 17117 7 lianhao.lu 2011-11-06 16:47:38 +0000 Normally, it will hang the system in less then 3 minutes. 17757 8 jessica.zhang 2011-12-20 11:29:50 +0000 Per today's bug triage, decide to re-assign the bug back to PRC since they have the HW setup to further investigate the issue and come up a clear context on the issue and then seek help from Darren... 24087 9 alexandru.c.georgescu 2012-08-16 10:42:14 +0000 Hi Jessica, Is there any update regarding the bug? Do you know if it's still reproducing? Thanks, Alex. 24127 10 jessica.zhang 2012-08-16 21:00:21 +0000 Since we no longer have the setup and lack of info on how to reproduce it