On 2019/10/16 0:58, Greg KH wrote:

On Tue, Oct 15, 2019 at 06:40:29PM +0800, Yunsheng Lin wrote:

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On 2019/10/14 17:25, Greg KH wrote:

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On Mon, Oct 14, 2019 at 04:00:46PM +0800, Yunsheng Lin wrote:

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On 2019/10/12 18:47, Greg KH wrote:

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On Sat, Oct 12, 2019 at 12:40:01PM +0200, Greg KH wrote:

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On Sat, Oct 12, 2019 at 05:47:56PM +0800, Yunsheng Lin wrote:

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On 2019/10/12 15:40, Greg KH wrote:

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On Sat, Oct 12, 2019 at 02:17:26PM +0800, Yunsheng Lin wrote:

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add pci and acpi maintainer
cc linux-pci@vger.kernel.org and linux-acpi@vger.kernel.org

On 2019/10/11 19:15, Peter Zijlstra wrote:

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On Fri, Oct 11, 2019 at 11:27:54AM +0800, Yunsheng Lin wrote:

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But I failed to see why the above is related to making node_to_cpumask_map()
NUMA_NO_NODE aware?

Your initial bug is for hns3, which is a PCI device, which really _MUST_
have a node assigned.

It not having one, is a straight up bug. We must not silently accept
NO_NODE there, ever.

I suppose you mean reporting a lack of affinity when the node of a pcie
device is not set by "not silently accept NO_NODE".

If the firmware of a pci device does not provide the node information,
then yes, warn about that.

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As Greg has asked about in [1]:
what is a user to do when the user sees the kernel reporting that?

We may tell user to contact their vendor for info or updates about
that when they do not know about their system well enough, but their
vendor may get away with this by quoting ACPI spec as the spec
considering this optional. Should the user believe this is indeed a
fw bug or a misreport from the kernel?

Say it is a firmware bug, if it is a firmware bug, that's simple.

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If this kind of reporting is common pratice and will not cause any
misunderstanding, then maybe we can report that.

Yes, please do so, that's the only way those boxes are ever going to get
fixed.  And go add the test to the "firmware testing" tool that is based
on Linux that Intel has somewhere, to give vendors a chance to fix this
before they ship hardware.

This shouldn't be a big deal, we warn of other hardware bugs all the
time.

Ok, thanks for clarifying.

Will send a patch to catch the case when a pcie device without numa node
being set and warn about it.

Maybe use dev->bus to verify if it is a pci device?

No, do that in the pci bus core code itself, when creating the devices
as that is when you know, or do not know, the numa node, right?

This can't be in the driver core only, as each bus type will have a
different way of determining what the node the device is on.  For some
reason, I thought the PCI core code already does this, right?

Yes, pci_irq_get_node(), which NO ONE CALLS!  I should go delete that
thing...

Anyway, it looks like the pci core code does call set_dev_node() based
on the PCI bridge, so if that is set up properly, all should be fine.

If not, well, you have buggy firmware and you need to warn about that at
the time you are creating the bridge.  Look at the call to
pcibus_to_node() in pci_register_host_bridge().

Thanks for pointing out the specific function.
Maybe we do not need to warn about the case when the device has a parent,
because we must have warned about the parent if the device has a parent
and the parent also has a node of NO_NODE, so do not need to warn the child
device anymore? like blew:

@@ -932,6 +932,10 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
        list_add_tail(&bus->node, &pci_root_buses);
        up_write(&pci_bus_sem);

+       if (nr_node_ids > 1 && !parent &&

Why do you need to check this?  If you have a parent, it's your node
should be set, if not, that's an error, right?

If the device has parent and the parent device also has a node of
NUMA_NO_NODE, then maybe we have warned about the parent device, so
we do not have to warn about the child device?

But it's a PCI bridge, if it is not set properly, that needs to be fixed
otherwise the PCI devices attached to it have no hope of working
properly.

You may be right, thanks.

If it's a root PCI bridge and it does have a parent device, but
the parent device is not a pcie device and it's node is NUMA_NO_NODE,
then we will miss warning about this case.

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In pci_register_host_bridge():

	if (!parent)
		set_dev_node(bus->bridge, pcibus_to_node(bus));

The above only set the node of the bridge device to the node of bus if
the bridge device does not have a parent.

Odd, what happens to devices behind another bridge today?  Are their
nodes set properly today?  Is the node supposed to be the same as the
parent bridge?

It seems only the root bridge is added in pci_register_host_bridge(),
and other bridges under the root bridge is added in pci_alloc_child_bus().

And in pci_alloc_child_bus(), the child bus device is setup with proper
parent, so the pcie device under the child bus should have the same node
as the parent bridge when device_add() is called, which will set the node
to its parent's node when the child device' node is NUMA_NO_NODE.

Do not have a system with multi bridges at hand to debug it, so I may
be wrong about above.

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+           dev_to_node(bus->bridge) == NUMA_NO_NODE)
+               dev_err(bus->bridge, FW_BUG "No node assigned on NUMA capable HW. Please contact your vendor for updates.\n");
+
        return 0;

Who set that bus->bridge node to NUMA_NO_NODE?

It seems x86 and arm64 may have different implemention of
pcibus_to_node():

For arm64:
int pcibus_to_node(struct pci_bus *bus)
{
	return dev_to_node(&bus->dev);
}

And the node of bus is set in:
int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
{
	if (!acpi_disabled) {
		struct pci_config_window *cfg = bridge->bus->sysdata;
		struct acpi_device *adev = to_acpi_device(cfg->parent);
		struct device *bus_dev = &bridge->bus->dev;

		ACPI_COMPANION_SET(&bridge->dev, adev);
		set_dev_node(bus_dev, acpi_get_node(acpi_device_handle(adev)));
	}

	return 0;
}

acpi_get_node() may return NUMA_NO_NODE in pcibios_root_bridge_prepare(),
which will set the node of bus_dev to NUMA_NO_NODE


x86:
static inline int __pcibus_to_node(const struct pci_bus *bus)
{
	const struct pci_sysdata *sd = bus->sysdata;

	return sd->node;
}

And the node of bus is set in pci_acpi_scan_root(), which uses
pci_acpi_root_get_node() get the node of a bus. And it also may return
NUMA_NO_NODE.

Fixing that will be good :)>

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If that is set, the firmware is broken, as you say, but you need to tell
the user what firmware is broken.

Maybe mentioning the BIOS in log?
dev_err(bus->bridge, FW_BUG "No node assigned on NUMA capable HW by BIOS. Please contact your vendor for updates.\n");

That's a good start.  Try running it on your machines (big and small)
and see what happens.

There is no fw bug log output as above when using newer bios(
which has provided the device node through ACPI) in my machine.

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Try something like this out and see what happens on your machine that
had things "broken".  What does it say?

Does not have a older bios right now.
But always returning NUMA_NO_NODE by below patch:

--- a/drivers/acpi/numa.c
+++ b/drivers/acpi/numa.c

@@ -484,6 +484,7 @@ int acpi_get_node(acpi_handle handle)

        pxm = acpi_get_pxm(handle);

-       return acpi_map_pxm_to_node(pxm);
+       return -1;
+       //return acpi_map_pxm_to_node(pxm);

it gives the blow warning in my machine:

[   16.126136]  pci0000:00: [Firmware Bug]: No node assigned on NUMA capable HW by BIOS. Please contact your vendor for updates.
[   17.733831]  pci0000:7b: [Firmware Bug]: No node assigned on NUMA capable HW by BIOS. Please contact your vendor for updates.
[   18.020924]  pci0000:7a: [Firmware Bug]: No node assigned on NUMA capable HW by BIOS. Please contact your vendor for updates.
[   18.552832]  pci0000:78: [Firmware Bug]: No node assigned on NUMA capable HW by BIOS. Please contact your vendor for updates.
[   19.514948]  pci0000:7c: [Firmware Bug]: No node assigned on NUMA capable HW by BIOS. Please contact your vendor for updates.
[   20.652990]  pci0000:74: [Firmware Bug]: No node assigned on NUMA capable HW by BIOS. Please contact your vendor for updates.
[   22.573200]  pci0000:80: [Firmware Bug]: No node assigned on NUMA capable HW by BIOS. Please contact your vendor for updates.
[   23.225355]  pci0000:bb: [Firmware Bug]: No node assigned on NUMA capable HW by BIOS. Please contact your vendor for updates.
[   23.514040]  pci0000:ba: [Firmware Bug]: No node assigned on NUMA capable HW by BIOS. Please contact your vendor for updates.
[   24.050107]  pci0000:b8: [Firmware Bug]: No node assigned on NUMA capable HW by BIOS. Please contact your vendor for updates.
[   25.017491]  pci0000:bc: [Firmware Bug]: No node assigned on NUMA capable HW by BIOS. Please contact your vendor for updates.
[   25.557974]  pci0000:b4: [Firmware Bug]: No node assigned on NUMA capable HW by BIOS. Please contact your vendor for updates.

And can you fix your bios?  If you can't then why are we going to warn
about this?

Yes, our new bios has fixed that.