linux-kernel - Re: [PATCH v12 3/3] Documentation: tracing: Add documentation about PCI tracepoints

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <8c8f7c7e-286a-4020-8fdf-ff025e92f19f@linux.alibaba.com>
Date: Wed, 15 Oct 2025 10:36:47 +0800
From: Shuai Xue <xueshuai@...ux.alibaba.com>
To: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
Cc: rostedt@...dmis.org, Lukas Wunner <lukas@...ner.de>,
 linux-pci@...r.kernel.org, LKML <linux-kernel@...r.kernel.org>,
 linux-edac@...r.kernel.org, linux-trace-kernel@...r.kernel.org,
 helgaas@...nel.org, mattc@...estorage.com, Jonathan.Cameron@...wei.com,
 bhelgaas@...gle.com, tony.luck@...el.com, bp@...en8.de, mhiramat@...nel.org,
 mathieu.desnoyers@...icios.com, oleg@...hat.com, naveen@...nel.org,
 davem@...emloft.net, anil.s.keshavamurthy@...el.com, mark.rutland@....com,
 peterz@...radead.org, tianruidong@...ux.alibaba.com
Subject: Re: [PATCH v12 3/3] Documentation: tracing: Add documentation about
 PCI tracepoints



在 2025/10/14 22:40, Ilpo Järvinen 写道:
> On Tue, 14 Oct 2025, Shuai Xue wrote:
> 
>> The PCI tracing system provides tracepoints to monitor critical hardware
>> events that can impact system performance and reliability. Add
>> documentation about it.
>>
>> Signed-off-by: Shuai Xue <xueshuai@...ux.alibaba.com>
>> ---
>>   Documentation/trace/events-pci.rst | 74 ++++++++++++++++++++++++++++++
>>   1 file changed, 74 insertions(+)
>>   create mode 100644 Documentation/trace/events-pci.rst
>>
>> diff --git a/Documentation/trace/events-pci.rst b/Documentation/trace/events-pci.rst
>> new file mode 100644
>> index 000000000000..500b27713224
>> --- /dev/null
>> +++ b/Documentation/trace/events-pci.rst
>> @@ -0,0 +1,74 @@
>> +.. SPDX-License-Identifier: GPL-2.0
>> +
>> +===========================
>> +Subsystem Trace Points: PCI
>> +===========================
>> +
>> +Overview
>> +========
>> +The PCI tracing system provides tracepoints to monitor critical hardware events
>> +that can impact system performance and reliability. These events normally show
>> +up here:
>> +
>> +	/sys/kernel/tracing/events/pci
>> +
>> +Cf. include/trace/events/pci.h for the events definitions.
>> +
>> +Available Tracepoints
>> +=====================
>> +
>> +pci_hp_event
>> +------------
>> +
>> +Monitors PCI hotplug events including card insertion/removal and link
>> +state changes.
>> +::
>> +
>> +    pci_hp_event  "%s slot:%s, event:%s\n"
>> +
>> +**Event Types**:
>> +
>> +* ``LINK_UP`` - PCIe link established
>> +* ``LINK_DOWN`` - PCIe link lost
>> +* ``CARD_PRESENT`` - Card detected in slot
>> +* ``CARD_NOT_PRESENT`` - Card removed from slot
>> +
>> +**Example Usage**:
>> +
>> +    # Enable the tracepoint
>> +    echo 1> /sys/kernel/debug/tracing/events/pci/pci_hp_event/enable
>> +
>> +    # Monitor events (the following output is generated when a device is hotplugged)
>> +    cat /sys/kernel/debug/tracing/trace_pipe
>> +       irq/51-pciehp-88      [001] .....  1311.177459: pci_hp_event: 0000:00:02.0 slot:10, event:CARD_PRESENT
>> +
>> +       irq/51-pciehp-88      [001] .....  1311.177566: pci_hp_event: 0000:00:02.0 slot:10, event:LINK_UP
>> +
>> +pcie_link_event
>> +---------------
>> +
>> +Monitors PCIe link speed changes and provides detailed link status information.
>> +::
>> +
>> +    pcie_link_event  "%s type:%d, reason:%d, cur_bus_speed:%s, max_bus_speed:%s, width:%u, flit_mode:%u, status:%s\n"
>> +
>> +**Parameters**:
>> +
>> +* ``type`` - PCIe device type (4=Root Port, etc.)
>> +* ``reason`` - Reason for link change:
>> +
>> +  - ``0`` - Link retrain
>> +  - ``1`` - Bus enumeration
>> +  - ``2`` - Bandwidth controller enable
>> +  - ``3`` - Bandwidth controller IRQ
> 
> Maybe these two should be called "Bandwidth notification" as that's the
> name of the underlying mechanism.

Sure, I will rename it.

> 
> For the entire series,
> 
> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>

Thanks.

Best Regards,
Shuai