Re: frequent softlockups with 3.10rc6.

[Dave Jones <davej@redhat.com>]

On Mon, Jun 24, 2013 at 06:37:08PM +0200, Oleg Nesterov wrote:
 > On 06/24, Dave Jones wrote:
 > >
 > > On Mon, Jun 24, 2013 at 10:52:29AM -0400, Steven Rostedt wrote:
 > >
 > >  > > >  check_list_nodes corruption. next->prev should be prev (ffff88023b8a1a08), but was 00ffff88023b8a1a. (next=ffff880243288001).
 > >  > >
 > >  > > Can't find "check_list_nodes" in lib/list_debug.c or elsewhere...
 > >  > >
 > >  > > >   [<ffffffff816e467d>] dump_stack+0x19/0x1b
 > >  > > >   [<ffffffff8104a0c1>] warn_slowpath_common+0x61/0x80
 > >  > > >   [<ffffffff8104a12c>] warn_slowpath_fmt+0x4c/0x50
 > >  > > >   [<ffffffff81112c61>] rb_head_page_deactivate.isra.39+0x61/0x80
 > >  > >
 > >  > > How? rb_list_head_clear() just modifies list->next directly.
 > >  > >
 > >  > > > hopefully despite that it'll actually function as intended.
 > >  > >
 > >  > > Yes ;)
 > >  >
 > >  > I'm curious to what happened.
 > >
 > > Ah, this is the first victim of my new 'check sanity of nodes during list walks' patch.
 > > It's doing the same prev->next next->prev checking as list_add and friends.
 > > I'm looking at getting it into shape for a 3.12 merge after some other preparatory patches
 > > go into 3.11
 > 
 > So you used the patched kernel when you hit the lockups ?
 > 
 > What else was changed?

I hit the lockups on the vanilla tree too.

	Dave