On Wed, 10 Jun 2015 15:17:23 +0800 Xishi Qiu <qiuxishi@xxxxxxxxxx> wrote: > Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000007 > > Pid: 1, comm: init Tainted: G R O 3.4.24.19-0.11-default #1 > Call Trace: > [<ffffffff8144dd24>] panic+0xc1/0x1e2 > [<ffffffff8104483b>] do_exit+0x7db/0x8d0 > [<ffffffff81044c7a>] do_group_exit+0x3a/0xa0 > [<ffffffff8105394b>] get_signal_to_deliver+0x1ab/0x5e0 > [<ffffffff81002270>] do_signal+0x60/0x5f0 > [<ffffffff8145bf97>] ? do_page_fault+0x4a7/0x4d0 > [<ffffffff81170d2c>] ? poll_select_copy_remaining+0xec/0x140 > [<ffffffff81002885>] do_notify_resume+0x65/0x80 > [<ffffffff8124ca7e>] ? trace_hardirqs_on_thunk+0x3a/0x3c > [<ffffffff814587ab>] retint_signal+0x4d/0x92 > > > The system has a little memory left, then reboot it, and get the panic. > Perhaps this is a bug and trigger it like this and the latest kernel maybe > also have the problem. > > use a lot of memory > wake up kswapd() > reclaim some pages from init thread (pid=1) > reboot > shutdown the disk > init thread read data from disk > page fault, because the page has already reclaimed > receive SIGBUS, and init thread exit > trigger the panic > > Interesting. 3.4 is a pretty old kernel but I expect at least some of this remains. - Why the heck did the disk get shut down while init still had pages on it? We shouldn't be able to get that far without having done a swapoff. - Ignoring the above, as far as I can tell a regular old I/O error during pagein of one of init's pages (anon or file-backed) will result in the delivery of SIGBUS to init. If init isn't catching SIGBUS (or if init's signal-handling code is also swapped out to a bad sector??) then we're going to kill init and the system will panic as above. I'm not sure what we can do in this situation - init has permanently lost some text or data and is hence dead. But panicing the system doesn't seem the correct response. -- 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>