Re: [PATCH v9 1/2] PCI: trace: Add a generic RAS tracepoint for hotplug event
From: Bjorn Helgaas <helgaas@kernel.org>
Date: 2025-07-25 21:09:15
Also in:
linux-edac, linux-pci, lkml
On Wed, Jul 23, 2025 at 11:31:07AM +0800, 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 output is like below:
$ echo 1 > /sys/kernel/debug/tracing/events/pci/pci_hp_event/enable
$ cat /sys/kernel/debug/tracing/trace_pipe
<...>-206 [001] ..... 40.373870: pci_hp_event: 0000:00:02.0 slot:10, event:LINK_DOWN
<...>-206 [001] ..... 40.374871: pci_hp_event: 0000:00:02.0 slot:10, event:CARD_NOT_PRESENTI asked about documentation earlier [1], but didn't see any response. I think these tracepoints are important and will be widely used, so it seems like some kind of user guide would be helpful.
Suggested-by: Lukas Wunner <lukas@wunner.de> Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Nit: I assume this came from the patch I had applied to pci/trace, but you shouldn't include any sign-offs from people to whom you send patches [2]. Bjorn [1] https://lore.kernel.org/all/20250717192950.GA2594528@bhelgaas/#t (local) [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?id=v6.13#n449