Hi,
Here is a series of patches which starts the boot-time tracing earlier,
core_initcall_sync, so that we can start tracing from postcore_initcall
instead of device_initcall.
The boot-time tracing is useful for debugging kernel drivers which are
embedded in the kernel. Since most of the drivers are initialized in the
device_initcall, the boot-time tracing which starts in fs_initcall, can
trace them. However, many frameworks and platform drivers are initialized
in subsys_initcall or arch_initcall and the boot-time tracing still
misses it.
This series will improve the boot-time tracing to trace those events.
- Move kprobes initialization into early_initcall from subsys_initcall
as same as jump_label and dynamic_debug.
Previously arm64 didn't allow it, but commit b322c65f8ca3 ("arm64:
Call debug_traps_init() from trap_init() to help early kgdb") fixed it.
- Fixes tracing init routines to decouple the tracefs entry creation
and the data-structure allocation/initialization.
- Move dynamic-events initialization to core_initcall and call boot-time
tracing in core_initcall_sync (the core_initcall_sync is called after
all core_initcall functions are done).
Thank you,
---
Masami Hiramatsu (6):
kprobes: Init kprobes in early_initcall
tracing: Define event fields early stage
tracing: Enable adding dynamic events early stage
tracing: Enable creating new instance early boot
tracing/boot,kprobe,synth: Initialize boot-time tracing earlier
Documentation: tracing: Add the startup timing of boot-time tracing
Documentation/trace/boottime-trace.rst | 14 ++++
kernel/kprobes.c | 2 -
kernel/trace/trace.c | 53 +++++++++++++----
kernel/trace/trace.h | 7 ++
kernel/trace/trace_boot.c | 7 ++
kernel/trace/trace_events.c | 101 ++++++++++++++++++++------------
kernel/trace/trace_events_synth.c | 22 +++++--
kernel/trace/trace_functions.c | 22 ++++---
kernel/trace/trace_kprobe.c | 6 +-
9 files changed, 165 insertions(+), 69 deletions(-)
--
Masami Hiramatsu (Linaro) <mhiramat@xxxxxxxxxx>
