| 8c3526fb | 27-Apr-2023 |
Florent Revest <[email protected]> |
arm64: ftrace: Add direct call trampoline samples support
The ftrace samples need per-architecture trampoline implementations
to save and restore argument registers around the calls to
my_direct_fun
arm64: ftrace: Add direct call trampoline samples support
The ftrace samples need per-architecture trampoline implementations
to save and restore argument registers around the calls to
my_direct_func* and to restore polluted registers (eg: x30).
These samples also include <asm/asm-offsets.h> which, on arm64, is not
necessary and redefines previously defined macros (resulting in
warnings) so these includes are guarded by !CONFIG_ARM64.
Link: https://lkml.kernel.org/r/[email protected]
Reviewed-by: Mark Rutland <[email protected]>
Tested-by: Mark Rutland <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Signed-off-by: Florent Revest <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
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| aef70ebd | 30-Jan-2023 |
Tom Rix <[email protected]> |
samples: ftrace: Make some global variables static
smatch reports this representative issue
samples/ftrace/ftrace-ops.c:15:14: warning: symbol 'nr_function_calls' was not declared. Should it be stat
samples: ftrace: Make some global variables static
smatch reports this representative issue
samples/ftrace/ftrace-ops.c:15:14: warning: symbol 'nr_function_calls' was not declared. Should it be static?
The nr_functions_calls and several other global variables are only
used in ftrace-ops.c, so they should be static.
Remove the instances of initializing static int to 0.
Link: https://lore.kernel.org/linux-trace-kernel/[email protected]
Signed-off-by: Tom Rix <[email protected]>
Acked-by: Mark Rutland <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
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| f94fe704 | 30-Jan-2023 |
Arnd Bergmann <[email protected]> |
ftrace: sample: avoid open-coded 64-bit division
Calculating the average period requires a 64-bit division that leads
to a link failure on 32-bit architectures:
x86_64-linux-ld: samples/ftrace/ftra
ftrace: sample: avoid open-coded 64-bit division
Calculating the average period requires a 64-bit division that leads
to a link failure on 32-bit architectures:
x86_64-linux-ld: samples/ftrace/ftrace-ops.o: in function `ftrace_ops_sample_init':
ftrace-ops.c:(.init.text+0x23b): undefined reference to `__udivdi3'
Use the div_u64() helper to do this instead. Since this is an init function that
is not called frequently, the runtime overhead is going to be acceptable.
Link: https://lore.kernel.org/linux-trace-kernel/[email protected]
Cc: Masami Hiramatsu <[email protected]>
Fixes: b56c68f705ca ("ftrace: Add sample with custom ops")
Signed-off-by: Arnd Bergmann <[email protected]>
Acked-by: Mark Rutland <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
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| b56c68f7 | 03-Jan-2023 |
Mark Rutland <[email protected]> |
ftrace: Add sample with custom ops
When reworking core ftrace code or architectural ftrace code, it's often
necessary to test/analyse/benchmark a number of ftrace_ops
configurations. This patch adds
ftrace: Add sample with custom ops
When reworking core ftrace code or architectural ftrace code, it's often
necessary to test/analyse/benchmark a number of ftrace_ops
configurations. This patch adds a module which can be used to explore
some of those configurations.
I'm using this to benchmark various options for changing the way
trampolines and handling of ftrace_ops work on arm64, and ensuring other
architectures aren't adversely affected.
For example, in a QEMU+KVM VM running on a 2GHz Xeon E5-2660
workstation, loading the module in various configurations produces:
| # insmod ftrace-ops.ko
| ftrace_ops: registering:
| relevant ops: 1
| tracee: tracee_relevant [ftrace_ops]
| tracer: ops_func_nop [ftrace_ops]
| irrelevant ops: 0
| tracee: tracee_irrelevant [ftrace_ops]
| tracer: ops_func_nop [ftrace_ops]
| saving registers: NO
| assist recursion: NO
| assist RCU: NO
| ftrace_ops: Attempted 100000 calls to tracee_relevant [ftrace_ops] in 1681558ns (16ns / call)
| # insmod ftrace-ops.ko nr_ops_irrelevant=5
| ftrace_ops: registering:
| relevant ops: 1
| tracee: tracee_relevant [ftrace_ops]
| tracer: ops_func_nop [ftrace_ops]
| irrelevant ops: 5
| tracee: tracee_irrelevant [ftrace_ops]
| tracer: ops_func_nop [ftrace_ops]
| saving registers: NO
| assist recursion: NO
| assist RCU: NO
| ftrace_ops: Attempted 100000 calls to tracee_relevant [ftrace_ops] in 1693042ns (16ns / call)
| # insmod ftrace-ops.ko nr_ops_relevant=2
| ftrace_ops: registering:
| relevant ops: 2
| tracee: tracee_relevant [ftrace_ops]
| tracer: ops_func_nop [ftrace_ops]
| irrelevant ops: 0
| tracee: tracee_irrelevant [ftrace_ops]
| tracer: ops_func_nop [ftrace_ops]
| saving registers: NO
| assist recursion: NO
| assist RCU: NO
| ftrace_ops: Attempted 100000 calls to tracee_relevant [ftrace_ops] in 11965582ns (119ns / call)
| # insmod ftrace-ops.ko save_regs=true
| ftrace_ops: registering:
| relevant ops: 1
| tracee: tracee_relevant [ftrace_ops]
| tracer: ops_func_nop [ftrace_ops]
| irrelevant ops: 0
| tracee: tracee_irrelevant [ftrace_ops]
| tracer: ops_func_nop [ftrace_ops]
| saving registers: YES
| assist recursion: NO
| assist RCU: NO
| ftrace_ops: Attempted 100000 calls to tracee_relevant [ftrace_ops] in 4459624ns (44ns / call)
Link: https://lkml.kernel.org/r/[email protected]
Cc: Florent Revest <[email protected]>
Acked-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Mark Rutland <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
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| 0daf5cb2 | 19-Dec-2021 |
Jiri Olsa <[email protected]> |
ftrace/samples: Add missing prototypes direct functions
There's another compilation fail (first here [1]) reported by kernel
test robot for W=1 clang build:
>> samples/ftrace/ftrace-direct-multi-
ftrace/samples: Add missing prototypes direct functions
There's another compilation fail (first here [1]) reported by kernel
test robot for W=1 clang build:
>> samples/ftrace/ftrace-direct-multi-modify.c:7:6: warning: no previous
prototype for function 'my_direct_func1' [-Wmissing-prototypes]
void my_direct_func1(unsigned long ip)
Direct functions in ftrace direct sample modules need to have prototypes
defined. They are already global in order to be visible for the inline
assembly, so there's no problem.
The kernel test robot reported just error for ftrace-direct-multi-modify,
but I got same errors also for the rest of the modules touched by this patch.
[1] 67d4f6e3bf5d ftrace/samples: Add missing prototype for my_direct_func
Link: https://lkml.kernel.org/r/[email protected]
Reported-by: kernel test robot <[email protected]>
Fixes: e1067a07cfbc ("ftrace/samples: Add module to test multi direct modify interface")
Fixes: ae0cc3b7e7f5 ("ftrace/samples: Add a sample module that implements modify_ftrace_direct()")
Fixes: 156473a0ff4f ("ftrace: Add another example of register_ftrace_direct() use case")
Fixes: b06457c83af6 ("ftrace: Add sample module that uses register_ftrace_direct()")
Signed-off-by: Jiri Olsa <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>
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