watchdogd stat location

[Mike Tancsa]

On 9/28/2019 3:30 PM, Ian Lepore wrote:
> If we want to be sure to force physical IO, how about dd if=/
> of=/dev/null count=1 ?
>
> But I question the premise of forcing physical IO as being somehow a
> better indicator of a non-hung system.  I think it's just a better
> indicator of the sdcard problem that Mike is experiencing.  For anyone
> else, forcing periodic physical IO is going to do annoying things like
> spin up idle drives.


I think in my case, I am going to need to do that.  I was hoping doing a
simple stat on / or /boot would do the trick to recover from

mmcsd0: Error indicated: 1 Timeout
g_vfs_done():mmcsd0s1a[READ(offset=267358208, length=4096)]error = 5
vnode_pager_generic_getpages_done: I/O read error 5
vm_fault: pager read error, pid 1 (init)
sdhci_pci0-slot0: Got AutoCMD12 error 0x0001, but there is no active
command.
sdhci_pci0-slot0: ============== REGISTER DUMP ==============
sdhci_pci0-slot0: Sys addr: 0x74ee0000 | Version:  0x00001001
sdhci_pci0-slot0: Blk size: 0x00005200 | Blk cnt:  0x00000008
sdhci_pci0-slot0: Argument: 0x0007f817 | Trn mode: 0x00000037
sdhci_pci0-slot0: Present:  0x01ff0000 | Host ctl: 0x00000007
sdhci_pci0-slot0: Power:    0x0000000f | Blk gap:  0x00000000
sdhci_pci0-slot0: Wake-up:  0x00000000 | Clock:    0x00000007
sdhci_pci0-slot0: Timeout:  0x0000000d | Int stat: 0x00000000
sdhci_pci0-slot0: Int enab: 0x01ff00fb | Sig enab: 0x01ff00fb
sdhci_pci0-slot0: AC12 err: 0x00000001 | Host ctl2:0x00000080
sdhci_pci0-slot0: Caps:     0x21fe32b2 | Caps2:    0x00000070
sdhci_pci0-slot0: Max curr: 0x00c80064 | ADMA err: 0x00000000
sdhci_pci0-slot0: ADMA addr:0x00000000 | Slot int: 0x000000ff
sdhci_pci0-slot0: ===========================================
g_vfs_done():mmcsd0s1a[READ(offset=267358208, length=4096)]error = 5
vnode_pager_generic_getpages_done: I/O read error 5

but it looks like no dice, at least in the one case I hit over the
weekend. However from the captured logs, not sure if watchogd really got
armed or not.

I think doing an actual raw read is the way to go, but to put that in
watchdogd feels like it would violate POLA.  I think instead, I will
make it an external command as it will fix my needs, or even roll my own
watchdogd which might even be better for me.

    ---Mike

-- 
-------------------
Mike Tancsa, tel +1 519 651 3400 x203
Sentex Communications, mike at sentex.net
Providing Internet services since 1994 www.sentex.net
Cambridge, Ontario Canada