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Currently, when a probe event is added using perf probe --add with a
hexadecimal type cast (e.g., var:x64 and var:x32), the kernel traceprobe
subsystem sets the field type to "u64" in the event's format file, yet
generates a print format specifier of "var=0x%Lx" or "0x%x".
By default, perf trace uses its internal beautifiers which only inspect
field->type and field->flags. Because traceprobe events declare
primitive integer field types ("u64") without a C pointer asterisk
(i.e., "*"), perf trace defaults to printing the field's value as a
decimal unsigned long ("%ld"), ignoring the hexadecimal intent.
Introduce field_has_hex_fmt() to inspect the tracepoint's print_fmt
format string. If a field's print format assignment uses hexadecimal
specifiers (i.e., "=0x", "=%#", or "=%p"), assign SCA_PTR formatting so
perf trace displays the value in hexadecimal by default without
requiring --libtraceevent. For example:
❯ sudo ./perf probe --add 'enqueue_task_fair rq=rq:x64 p=p:x64 flags=flags:x32'
Added new event:
probe:enqueue_task_fair (on enqueue_task_fair with rq=rq:x64 p=p:x64 flags=flags:x32)
You can now use it in all perf tools, such as:
perf record -e probe:enqueue_task_fair -aR sleep 1
❯ sudo ./perf trace --show-cpu --event probe:enqueue_task_fair --max-event 3
0.000 [000] :0/0 probe:enqueue_task_fair(rq: 0xffff8ac632233180, p: 0xffff8ac2c1240000, flags: 0x100009)
0.006 [004] :0/0 probe:enqueue_task_fair(rq: 0xffff8ac632433180, p: 0xffff8ac624cf8000, flags: 0x9)
0.069 [001] :0/0 probe:enqueue_task_fair(rq: 0xffff8ac6322b3180, p: 0xffff8ac4c4212c40, flags: 0x9)
Signed-off-by: Aaron Tomlin <atomlin@atomlin.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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