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authorHuang Yiwei <quic_hyiwei@quicinc.com>2024-02-23 09:31:26 +0100
committerSteven Rostedt (Google) <rostedt@goodmis.org>2024-03-18 15:33:06 +0100
commit19f0423fd55c301c8edaea286e568ec657f42750 (patch)
tree128ac4691ca60f9df0af61997c310ee138640919 /kernel/sysctl.c
parenttracing: Remove second parameter to __assign_rel_str() (diff)
downloadlinux-19f0423fd55c301c8edaea286e568ec657f42750.tar.xz
linux-19f0423fd55c301c8edaea286e568ec657f42750.zip
tracing: Support to dump instance traces by ftrace_dump_on_oops
Currently ftrace only dumps the global trace buffer on an OOPs. For debugging a production usecase, instance trace will be helpful to check specific problems since global trace buffer may be used for other purposes. This patch extend the ftrace_dump_on_oops parameter to dump a specific or multiple trace instances: - ftrace_dump_on_oops=0: as before -- don't dump - ftrace_dump_on_oops[=1]: as before -- dump the global trace buffer on all CPUs - ftrace_dump_on_oops=2 or =orig_cpu: as before -- dump the global trace buffer on CPU that triggered the oops - ftrace_dump_on_oops=<instance_name>: new behavior -- dump the tracing instance matching <instance_name> - ftrace_dump_on_oops[=2/orig_cpu],<instance1_name>[=2/orig_cpu], <instrance2_name>[=2/orig_cpu]: new behavior -- dump the global trace buffer and multiple instance buffer on all CPUs, or only dump on CPU that triggered the oops if =2 or =orig_cpu is given Also, the sysctl node can handle the input accordingly. Link: https://lore.kernel.org/linux-trace-kernel/20240223083126.1817731-1-quic_hyiwei@quicinc.com Cc: Ross Zwisler <zwisler@google.com> Cc: <mhiramat@kernel.org> Cc: <mark.rutland@arm.com> Cc: <mcgrof@kernel.org> Cc: <keescook@chromium.org> Cc: <j.granados@samsung.com> Cc: <mathieu.desnoyers@efficios.com> Cc: <corbet@lwn.net> Signed-off-by: Huang Yiwei <quic_hyiwei@quicinc.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/sysctl.c')
-rw-r--r--kernel/sysctl.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 157f7ce2942d..81cc974913bb 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1710,9 +1710,9 @@ static struct ctl_table kern_table[] = {
{
.procname = "ftrace_dump_on_oops",
.data = &ftrace_dump_on_oops,
- .maxlen = sizeof(int),
+ .maxlen = MAX_TRACER_SIZE,
.mode = 0644,
- .proc_handler = proc_dointvec,
+ .proc_handler = proc_dostring,
},
{
.procname = "traceoff_on_warning",