On Mon, 12 May 2025, Shuai Xue wrote: > Hotplug events are critical indicators for analyzing hardware health, > particularly in AI supercomputers where surprise link downs can > significantly impact system performance and reliability. > > To this end, define a new TRACING_SYSTEM named pci, add a generic RAS > tracepoint for hotplug event to help healthy check, and generate > tracepoints for pcie hotplug event. Add enum pci_hotplug_event in > include/uapi/linux/pci.h so applications like rasdaemon can register > tracepoint event handlers for it. > > The output 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 present > > Suggested-by: Lukas Wunner <lu...@wunner.de> > Suggested-by: Steven Rostedt <rost...@goodmis.org> > Signed-off-by: Shuai Xue <xuesh...@linux.alibaba.com> > Reviewed-by: Lukas Wunner <lu...@wunner.de> > Reviewed-by: Jonathan Cameron <jonathan.came...@huawei.com> > --- > changes since v7: > - replace the TRACE_INCLUDE_PATH to avoid macro conflict per Steven > - pick up Reviewed-by from Lukas Wunner > --- > drivers/pci/hotplug/Makefile | 3 ++ > drivers/pci/hotplug/pciehp_ctrl.c | 33 ++++++++++++--- > drivers/pci/hotplug/trace.h | 68 +++++++++++++++++++++++++++++++ > include/uapi/linux/pci.h | 7 ++++ > 4 files changed, 105 insertions(+), 6 deletions(-) > create mode 100644 drivers/pci/hotplug/trace.h > > diff --git a/drivers/pci/hotplug/Makefile b/drivers/pci/hotplug/Makefile > index 40aaf31fe338..a1a9d1e98962 100644 > --- a/drivers/pci/hotplug/Makefile > +++ b/drivers/pci/hotplug/Makefile > @@ -3,6 +3,9 @@ > # Makefile for the Linux kernel pci hotplug controller drivers. > # > > +# define_trace.h needs to know how to find our header > +CFLAGS_pciehp_ctrl.o := -I$(src) > + > obj-$(CONFIG_HOTPLUG_PCI) += pci_hotplug.o > obj-$(CONFIG_HOTPLUG_PCI_COMPAQ) += cpqphp.o > obj-$(CONFIG_HOTPLUG_PCI_IBM) += ibmphp.o > diff --git a/drivers/pci/hotplug/pciehp_ctrl.c > b/drivers/pci/hotplug/pciehp_ctrl.c > index d603a7aa7483..f9beb4d3a9b8 100644 > --- a/drivers/pci/hotplug/pciehp_ctrl.c > +++ b/drivers/pci/hotplug/pciehp_ctrl.c > @@ -23,6 +23,9 @@ > #include "../pci.h" > #include "pciehp.h" > > +#define CREATE_TRACE_POINTS > +#include "trace.h"
Hi, Instead of spreading tracepoint creating into subdriver code like this, should we place it into one place, e.g., drivers/pci/pci-trace.c (which is what I seem to have used in my yet to be submitted patch that adds tracepoints into bwctrl link speed events)? > diff --git a/drivers/pci/hotplug/trace.h b/drivers/pci/hotplug/trace.h > new file mode 100644 > index 000000000000..21329c198019 > --- /dev/null > +++ b/drivers/pci/hotplug/trace.h Perhaps in include/trace/events/pci.h (or include/trace/events/pci-hotplug.h)? I don't know what is the general rule having them inside drivers/ vs include/trace/events, Documentation/trace/tracepoints.rst only mentions the latter, but there seems to be plenty under drivers/ too. > @@ -0,0 +1,68 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +#if !defined(_TRACE_HW_EVENT_PCI_HP_H) || defined(TRACE_HEADER_MULTI_READ) > +#define _TRACE_HW_EVENT_PCI_HP_H > + > +#include <linux/tracepoint.h> > + > +#undef TRACE_SYSTEM > +#define TRACE_SYSTEM pci > + > +#define PCI_HOTPLUG_EVENT \ -- i.
