ftrace: ftrace_dump_on_oops=[tracer]
Subsystems (2)
PATCH 1/1 ftrace: ftrace_dump_on_oops=[tracer]
seems useful to debug crashes that happen before I read userspace.
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Documentation/kernel-parameters.txt +4 -0
@@ -765,6 +765,10 @@ and is between 256 and 4096 characters. It is defined in the file parameter will force ia64_sal_cache_flush to call ia64_pal_cache_flush instead of SAL_CACHE_FLUSH. + ftrace_dump_on_oops=[tracer] + [ftrace] will dump the trace buffers on oops and + optionally set and start the specified tracer. + gamecon.map[2|3]= [HW,JOY] Multisystem joystick and NES/SNES/PSX pad support via parallel port (up to 5 devices per port)
kernel/trace/trace.c +32 -20
76 lines not on this page · raw message
Steven Rostedt
maintainerQuoted 1 line · Peter Zijlstra
seems useful to debug crashes that happen before I read userspace.
Hmm, I think it might be better to separate this from the dump_on_oops. How about a ftrace_default_tracer parameter?
If one is defined, it is activated as soon as it is initialized. This way we decouple the dump_on_oops, which we may not always want, and a way to start tracers before the switch to user space.
-- Steve
Quoted 10 lines · Steven Rostedt
Quoted 1 line · Peter Zijlstra
seems useful to debug crashes that happen before I read userspace.
Hmm, I think it might be better to separate this from the
dump_on_oops. How about aftrace_default_tracerparameter?If one is defined, it is activated as soon as it is initialized. This way we decouple the
dump_on_oops, which we may not always want, and a way to start tracers before the switch to user space.
Like so?
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Subject: ftrace: enable setting an ftrace tracer on boot
In order to facilitate early boot trouble, allow one to specify a tracer on the kernel boot line.
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Documentation/kernel-parameters.txt +8 -0
@@ -765,6 +765,14 @@ and is between 256 and 4096 characters. It is defined in the file parameter will force ia64_sal_cache_flush to call ia64_pal_cache_flush instead of SAL_CACHE_FLUSH. + ftrace=[tracer] + [ftrace] will set and start the specified tracer + as early as possible in order to facilitate early + boot debugging. + + ftrace_dump_on_oops + [ftrace] will dump the trace buffers on oops. + gamecon.map[2|3]= [HW,JOY] Multisystem joystick and NES/SNES/PSX pad support via parallel port (up to 5 devices per port)
kernel/trace/trace.c +38 -20
79 lines not on this page · raw message
Quoted 5 lines · Peter Zijlstra
Quoted 4 lines · Steven Rostedt
Quoted 1 line · Peter Zijlstra
seems useful to debug crashes that happen before I read userspace.
Quoted 8 lines
Quoted 6 lines
Hmm, I think it might be better to separate this from the
dump_on_oops. How about aftrace_default_tracerparameter?If one is defined, it is activated as soon as it is initialized. This way we decouple the
dump_on_oops, which we may not always want, and a way to start tracers before the switch to user space.Like so?
Sure.
Quoted 8 lines
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Subject: ftrace: enable setting an ftrace tracer on bootIn order to facilitate early boot trouble, allow one to specify a tracer on the kernel boot line.
Signed-off-by Peter Zijlstra <[email protected]>
-- Steve
Ingo Molnar
AppliedQuoted 23 lines · Steven Rostedt
Quoted 5 lines · Peter Zijlstra
Quoted 4 lines · Steven Rostedt
Quoted 1 line · Peter Zijlstra
seems useful to debug crashes that happen before I read userspace.
Quoted 8 lines
Quoted 6 lines
Hmm, I think it might be better to separate this from the
dump_on_oops. How about aftrace_default_tracerparameter?If one is defined, it is activated as soon as it is initialized. This way we decouple the
dump_on_oops, which we may not always want, and a way to start tracers before the switch to user space.Like so?
Sure.
Quoted 4 lines
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Subject: ftrace: enable setting an ftrace tracer on boot
Quoted 6 lines
Quoted 4 lines
In order to facilitate early boot trouble, allow one to specify a tracer on the kernel boot line.
Signed-off-by Peter Zijlstra <[email protected]>Acked-by Steven Rostedt <[email protected]>
applied to tip/tracing/ftrace, thanks guys!
Ingo