Re: 2.6.16-mm1

[Jens Axboe <axboe@suse.de>]

On Fri, Mar 24 2006, Brandon Low wrote:
> I recreated the oops with an untainted kernel, but didn't manage to copy that one down.
> 
> Brandon
> 
> usb 1-8: USB disconnect, address 6
> BUG: unable to handle kernel NULL pointer dereference at virtual address 00000102
>  printing eip:
> c023e447
> *pde = 00000000
> Oops: 0000 [#1]
> SMP
> last sysfs file: /block/sda/sda2/size
> Modules linked in: nls_cp437 deadline_iosched sd_mod vfat fat wlan_tkip wlan_scan_sta ath_pci ath_rate_sample wlan ath_hal w83627hf
> hwmon_vid eeprom i2c_isa i2c_ali1563 i2c_core snd_pcm_oss snd_mixer_oss snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_ali5451 snd_ac97_codec
> +snd_ac97_bus snd_pcm snd_timer snd soundcore snd_page_alloc rtc pcspkr
> CPU:    1
> EIP:    0060:[<c023e447>]    Tainted: PF     VLI
> EFLAGS: 00010046   (2.6.16-mm1 #1)
> EIP is at cfq_exit_single_io_context+0x27/0x110
> eax: 00000086   ebx: f7dcc124   ecx: f7dcc124   edx: f7dcc124
> esi: f645b200   edi: 00000006   ebp: 0000000f   esp: f6a99e44
> ds: 007b   es: 007b   ss: 0068
> Process hald-addon-stor (pid: 11786, threadinfo=f6a99000 task=f6546030)
> Stack: <0>f65460e8 00000001 f6c1c070 f6546030 f7dcc124 00000282 c1b4d384 c023e55a
>        f7dcc124 f6a99000 00000286 c02398c7 c1b4d384 c18de960 f6546030 c1b4d384
>        c01213f6 f6546030 c0452b40 f654649c f6a99f24 00000001 f7e66500 f6a99000
> Call Trace:
>  <c023e55a> cfq_exit_io_context+0x2a/0x50   <c02398c7> exit_io_context+0x87/0xb0
>  <c01213f6> do_exit+0x2a6/0x460   <c012161c> do_group_exit+0x3c/0x90
>  <c012c6c9> get_signal_to_deliver+0x229/0x300   <c0102da9> do_signal+0x69/0x160
>  <c013781e> ktime_get_ts+0x5e/0x70   <c0246ca2> copy_to_user+0x42/0x60
>  <c013807e> hrtimer_nanosleep+0xce/0x150   <c0137f90> nanosleep_wakeup+0x0/0x20
>  <c0138167> sys_nanosleep+0x67/0x70   <c0102ed8> do_notify_resume+0x38/0x3c
>  <c0103076> work_notifysig+0x13/0x19
> Code: 00 00 00 00 83 ec 1c 89 5c 24 10 8b 5c 24 20 89 74 24 14 89 7c 24 18 8b 73 10 85 f6 74 65 8b 3e 9c 58 f6 c4 02 0f 85 82 00 00
> 00 <8b> 87 fc 00 00 00 e8 0e 3b 15 00 8b 43 14 85 c0 75 57 8b 43 18
>  <1>Fixing recursive fault but reboot is needed!

Hmm, no luck reproducing this so far, strange. I'm using
2.6.16-block.git cfq branch exclusively, which is the patch you backed
out. I guess I'll try 2.6.16-mm1 on the same box next.

Can you try 2.6.16-mm1 with this patch applied on top?

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 81edf51..89fcc2c 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1516,6 +1516,7 @@ cfq_cic_rb_add(struct cfq_data *cfqd, st
 
 	rb_link_node(&cic->rb_node, parent, p);
 	rb_insert_color(&cic->rb_node, &ioc->cic_root);
+	list_add(&cic->queue_list, &cfqd->cic_list);
 	read_unlock(&cfq_exit_lock);
 }
 

-- 
Jens Axboe