Re: CFS review

[Chuck Ebbert <cebbert@redhat.com>]

On 08/29/2007 03:56 PM, Rene Herman wrote:
> 
> Before people focuss on software rendering too much -- also with 1.3.0 (and
> a Matrox Millenium G550 AGP, 32M) glxgears also works decidedly crummy
> using
> hardware rendering. While I can move the glxgears window itself, the actual
> spinning wheels stay in the upper-left corner of the screen and the
> movement
> leaves a non-repainting trace on the screen. Running a second instance of
> glxgears in addition seems to make both instances unkillable  -- and when
> I just now forcefully killed X in this situation (the spinning wheels were
> covering the upper left corner of all my desktops) I got the below.
> 
> Kernel is 2.6.22.5-cfs-v20.5, schedule() is in the traces (but that may be
> expected anyway).
> 

And this doesn't happen at all with the stock scheduler? (Just confirming,
in case you didn't compare.)

> BUG: unable to handle kernel NULL pointer dereference at virtual address
> 00000010
>  printing eip:
> c10ff416
> *pde = 00000000
> Oops: 0000 [#1]
> PREEMPT

Try it without preempt?

> Modules linked in: nfsd exportfs lockd nfs_acl sunrpc nls_iso8859_1
> nls_cp437 vfat fat nls_base
> CPU:    0
> EIP:    0060:[<c10ff416>]    Not tainted VLI
> EFLAGS: 00210246   (2.6.22.5-cfs-v20.5-local #5)
> EIP is at mga_dma_buffers+0x189/0x2e3
> eax: 00000000   ebx: efd07200   ecx: 00000001   edx: efc32c00
> esi: 00000000   edi: c12756cc   ebp: dfea44c0   esp: dddaaec0
> ds: 007b   es: 007b   fs: 0000  gs: 0033  ss: 0068
> Process glxgears (pid: 1775, ti=dddaa000 task=e9daca60 task.ti=dddaa000)
> Stack: efc32c00 00000000 00000004 e4c3bd20 c10fa54b e4c3bd20 efc32c00
> 00000000
>        00000004 00000000 00000000 00000000 00000000 00000001 00010000
> bfbdb8bc
>        bfbdb8b8 00000000 c10ff28d 00000029 c12756cc dfea44c0 c10f87fc
> bfbdb844
> Call Trace:
>  [<c10fa54b>] drm_lock+0x255/0x2de
>  [<c10ff28d>] mga_dma_buffers+0x0/0x2e3
>  [<c10f87fc>] drm_ioctl+0x142/0x18a
>  [<c1005973>] do_IRQ+0x97/0xb0
>  [<c10f86ba>] drm_ioctl+0x0/0x18a
>  [<c10f86ba>] drm_ioctl+0x0/0x18a
>  [<c105b0d7>] do_ioctl+0x87/0x9f
>  [<c105b32c>] vfs_ioctl+0x23d/0x250
>  [<c11b533e>] schedule+0x2d0/0x2e6
>  [<c105b372>] sys_ioctl+0x33/0x4d
>  [<c1003d1e>] syscall_call+0x7/0xb
>  =======================
> Code: 9a 08 03 00 00 8b 73 30 74 14 c7 44 24 04 28 76 1c c1 c7 04 24 49
> 51 23 c1 e8 b0 74 f1 ff 8b 83 d8 00 00 00 83 3d 1c 47 30 c1 00 <8b> 40
> 10 8b a8 58 1e 00 00 8b 43 28 8b b8 64 01 00 00 74 32 8b
> EIP: [<c10ff416>] mga_dma_buffers+0x189/0x2e3 SS:ESP 0068:dddaaec0

dev->dev_private->mmio is NULL when trying to access mmio.handle