Re: cpu hotplug oops on 2.6.15-rc5

[Sonny Rao <sonny@burdell.org>]

On Thu, Dec 22, 2005 at 10:37:50AM -0800, Ravikiran G Thirumalai wrote:
> On Thu, Dec 22, 2005 at 12:53:11PM -0500, Sonny Rao wrote:
> > On Thu, Dec 22, 2005 at 11:37:00AM -0600, Sonny Rao wrote:
> > > On Thu, Dec 22, 2005 at 01:27:43AM -0800, Ravikiran G Thirumalai wrote:
> > > > On Mon, Dec 19, 2005 at 12:16:59AM -0500, Sonny Rao wrote:
> > > > > (apologies if this is a dup)
> > > > ...
> > > > Sonny,
> > > > Does this patch fix the issue?   This one applies cleanly on 2.6.15-rc6
> > > > unlike the one that was sent to you earlier.
> > > 
> > > Hi, thanks, now I'm getting a slightly different error, 
> > > hitting a BUG in the slab debug code:
> > > 
> > > ihplus:~ # echo 0 > /sys/devices/system/cpu/cpu14/online 
> > > cpu 0x4: Vector: 700 (Program Check) at [c0000003a8c233f0]
> > >     pc: c00000000009bb2c: .check_slabp+0x130/0x188
> > >     lr: c00000000009bb28: .check_slabp+0x12c/0x188
> > >     sp: c0000003a8c23670
> > >    msr: 8000000000021032
> > >   current = 0xc0000001b95297f0
> > >   paca    = 0xc0000000005d7000
> > >     pid   = 11116, comm = bash
> > > kernel BUG in check_slabp at mm/slab.c:2368!
> > > enter ? for help
> > > 
> > > 
> > > 4:mon> t
> > > [c0000003a8c23700] c00000000009d918 .free_block+0x168/0x294
> > > [c0000003a8c237e0] c00000000009d1dc .kfree+0x2b8/0x2d4
> > > [c0000003a8c238a0] c0000000000a1644 .cpuup_callback+0x144/0x618
> > > [c0000003a8c239b0] c0000000004a0780 .notifier_call_chain+0x68/0x9c
> > > [c0000003a8c23a40] c00000000007d608 .cpu_down+0x1fc/0x358
> > > [c0000003a8c23b30] c0000000002bb4ec .store_online+0x88/0xe8
> > > [c0000003a8c23bc0] c0000000002b5c14 .sysdev_store+0x4c/0x68
> > > [c0000003a8c23c40] c000000000119c6c .sysfs_write_file+0x118/0x1bc
> > > [c0000003a8c23cf0] c0000000000c6078 .vfs_write+0x100/0x200
> > > [c0000003a8c23d90] c0000000000c6288 .sys_write+0x54/0x9c
> > > [c0000003a8c23e30] c000000000008600 syscall_exit+0x0/0x18
> > > --- Exception: c01 (System Call) at 000000000fe5ec10
> > > SP (ff865560) is in userspace
> > 
> > More details: 
> > 
> > The above crash was with SMT on, and I had already off-lined the SMT
> > sibling thread.  
> > 
> > When I boot with SMT off, I get a slightly different crash:
> 
> I think i missed the first reply above. (I can't seem to find it on lkml
> either).  So just to confirm, both these crashes are with the new patch on
> top of rc6?

Yes, rc6 + the patch you provided.

The stupid mail relay server I'm using for my ibm account seems to be very
lethargic, sorry about that. 

Sonny