On Thu, 22 Dec 2011, Tejun Heo wrote: > On Thu, Dec 22, 2011 at 03:46:39PM -0800, Tejun Heo wrote: > > On Thu, Dec 22, 2011 at 03:44:27PM -0800, Andrew Morton wrote: > > > > Weird, I can't reproduce the problem on block/for-3.3/core. Trying > > > > linux-next... hmmm, it works there too. > > > > > > This machine is next to my desk, about 50 yards from your cube ;) > > > > Heh, physical access feels like such distant concept. :) > > > > I'll test with the config and if I still can't reproduce it, play with > > your machine. > > Couldn't reproduce it on block/for-3.3 or next & you were already > gone. Is anyone else seeing this? Twice today, on ThinkPad T420s running 3.2.0-rc6-next-20111222. I haven't seen it at all under heavy load, but twice when simply rebuilding the kernel - I think both times it hung with "LD whatever/built-in.o" the last line on screen. I had (a variant of) kdb in, here's the stack it gave me, but I think I've got a bug in there which has missed out a number of stackframes: so don't waste time puzzling over any anomalies in it, but there's enough to suggest it's the same as Andrew was seeing. ffff880013ac2100 28524 28522 1* D ffff880013ac2538 sh RSP RIP Function (args) ffff88004165f820 ffffffff814e559a _raw_spin_unlock_irq+0x31 ffff88004165f858 ffffffff811d2867 get_request_wait+0xab ffff88004165f8b8 ffffffff811cfb75 elv_merge+0xa0 ffff88004165fd18 ffffffff810ca90c do_writepages+0x1f ffff88004165fd28 ffffffff810c2671 __filemap_fdatawrite_range+0x4e ffff88004165fd68 ffffffff810c2e92 filemap_flush+0x17 ffff88004165fd78 ffffffff8116533e ext4_alloc_da_blocks+0x28 ffff88004165fd88 ffffffff81160f6a ext4_release_file+0x2e ffff88004165fdb8 ffffffff811077d4 __fput+0x107 ffff88004165fe08 ffffffff81107899 fput+0x15 ffff88004165fe18 ffffffff81104037 filp_close+0x6b ffff88004165fe48 ffffffff81056b47 close_files+0x16a ffff88004165fea8 ffffffff81057f31 put_files_struct+0x21 ffff88004165fed8 ffffffff81058107 exit_files+0x46 ffff88004165ff08 ffffffff81058648 do_exit+0x20e ffff88004165ff48 ffffffff810588d1 do_group_exit+0x7d ffff88004165ff78 ffffffff8105890e sys_exit_group+0x12 I interrupted a few more times, yes, once or twice I caught it in some cfq io_context business: didn't take much notice because I thought I'd saved the stack to log, but it hasn't appeared in my /var/log/messages after reboot. Once or twice there was another sh running on another cpu, showing a very similar stack. Hugh -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
