Re: [PATCH v10 1/3] PCI: trace: Add a generic RAS tracepoint for hotplug event

Shuai Xue
2025-09-23T02:09:03Z

在 2025/9/22 21:10, Ilpo Järvinen 写道:
> On Sat, 20 Sep 2025, Shuai Xue wrote:
>
>> Hotplug events are critical indicators for analyzing hardware health,
>> and surprise link downs can significantly impact system performance and
>> reliability.
>>
>> Define a new TRACING_SYSTEM named "pci", add a generic RAS tracepoint
>> for hotplug event to help health checks. Add enum pci_hotplug_event in
>> include/uapi/linux/pci.h so applications like rasdaemon can register
>> tracepoint event handlers for it.
>>
>> The following output is generated when a device is hotplugged:
>>
>> $ echo 1 > /sys/kernel/debug/tracing/events/pci/pci_hp_event/enable
>> $ 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
>>
>> Suggested-by: Lukas Wunner <lukas@wunner.de>
>> Suggested-by: Steven Rostedt <rostedt@goodmis.org>
>> Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
>> Reviewed-by: Lukas Wunner <lukas@wunner.de>
>> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
>> ---
>> drivers/pci/Makefile | 2 +
>> drivers/pci/hotplug/Makefile | 3 +-
>> drivers/pci/hotplug/pciehp_ctrl.c | 31 ++++++++++++---
>> drivers/pci/trace.c | 11 ++++++
>> include/trace/events/pci.h | 63 +++++++++++++++++++++++++++++++
>> include/uapi/linux/pci.h | 7 ++++
>> 6 files changed, 110 insertions(+), 7 deletions(-)
>> create mode 100644 drivers/pci/trace.c
>> create mode 100644 include/trace/events/pci.h
>>
>> diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
>> index 67647f1880fb..bf389bc4dd3c 100644
>> --- a/drivers/pci/Makefile
>> +++ b/drivers/pci/Makefile
>> @@ -45,3 +45,5 @@ obj-y += controller/
>> obj-y += switch/
>>
>> subdir-ccflags-$(CONFIG_PCI_DEBUG) := -DDEBUG
>> +
>> +CFLAGS_trace.o := -I$(src)
>> diff --git a/drivers/pci/hotplug/Makefile b/drivers/pci/hotplug/Makefile
>> index 40aaf31fe338..d41f7050b072 100644
>> --- a/drivers/pci/hotplug/Makefile
>> +++ b/drivers/pci/hotplug/Makefile
>> @@ -65,7 +65,8 @@ rpadlpar_io-objs := rpadlpar_core.o \
>> pciehp-objs := pciehp_core.o \
>> pciehp_ctrl.o \
>> pciehp_pci.o \
>> - pciehp_hpc.o
>> + pciehp_hpc.o \
>> + ../trace.o
>
> To make it useful for any PCI tracing, not juse hotplug, this object file
> should be added in drivers/pci/Makefile, not here.

Make sence. How about adding to the main CONFIG_PCI object:

diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index bf389bc4dd3c..d7f83d06351d 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -5,7 +5,7 @@
obj-$(CONFIG_PCI) += access.o bus.o probe.o host-bridge.o \
remove.o pci.o pci-driver.o search.o \
rom.o setup-res.o irq.o vpd.o \
- setup-bus.o vc.o mmap.o devres.o
+ setup-bus.o vc.o mmap.o devres.o trace.o

obj-$(CONFIG_PCI) += msi/
obj-$(CONFIG_PCI) += pcie/

Thanks.

Best Regards,
Shuai