Re: [PATCH v5 09/13] PCI: Introduce /sys/bus/pci/devices/.../remove

From: Alex Chiang
Date: Wed Mar 25 2009 - 01:22:30 EST


* Kenji Kaneshige <kaneshige.kenji@xxxxxxxxxxxxxx>:
> Alex Chiang wrote:
> > * Kenji Kaneshige <kaneshige.kenji@xxxxxxxxxxxxxx>:
> >> I still have the following kernel error messages in testing with your
> >> latest set of patches (Jesse's linux-next). The test case is removing
> >> e1000e device or its parent bridge by "echo 1 > /sys/bus/pci/devices/
> >> .../remove".
> >>
> >> [ 537.379995] =============================================
> >> [ 537.380124] [ INFO: possible recursive locking detected ]
> >> [ 537.380128] 2.6.29-rc8-kk #1
> >> [ 537.380128] ---------------------------------------------
> >> [ 537.380128] events/4/56 is trying to acquire lock:
> >> [ 537.380128] (events){--..}, at: [<ffffffff80257fc0>] flush_workqueue+0x0/0xa0
> >> [ 537.380128]
> >> [ 537.380128] but task is already holding lock:
> >> [ 537.380128] (events){--..}, at: [<ffffffff80257648>] run_workqueue+0x108/0x230
> >> [ 537.380128]
> >> [ 537.380128] other info that might help us debug this:
> >> [ 537.380128] 3 locks held by events/4/56:
> >> [ 537.380128] #0: (events){--..}, at: [<ffffffff80257648>] run_workqueue+0x108/0x230
> >> [ 537.380128] #1: (&ss->work){--..}, at: [<ffffffff80257648>] run_workqueue+0x108/0x230
> >> [ 537.380128] #2: (pci_remove_rescan_mutex){--..}, at: [<ffffffff803c10d1>] remove_callback+0x21/0x40
> >
> > I still cannot reproduce this lockdep issue, even using your
> > .config with an e1000e device on an x86_64 kernel. :(
> >
> > I tried removing the endpoint, an intermediate bridge device, and
> > the parent bus. I don't know what I'm doing wrong...
> >
>
> I don't know either...
> The reproducibility is 100% on my environment. The steps are
> just boot the system and remove the device.
>
> > Can you please try this patch though, and see if it fixes the
> > warning? It applies on top of my other sysfs patch that
> > introduces a mutex in sysfs_schedule_callback.
>
> Anyway, I confirmed the kernel error messages were gone with
> the patch against sysfs. Note that I used the following patch
> I made for testing instead since your patch could not be
> applied to Jesse's linux-next.

Great, thank you for testing Kenji-san.

/ac

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/