Demo of custom userspace probe points

demo.c

#include <stdio.h>
#include <string.h>

#include "sofs_probes.h"

static void chord_put(int policy, const char *msg) {
        SOFS_PROBES_CHORD_PUT(policy, strlen(msg));
        printf("%s\n", msg);
}

int main(int argc, char **argv) {
        chord_put(1, "Hello, world!");
        return 0;
}

Makefile

DTRACE := dtrace

default: demo

sofs_probes.h: sofs_probes.d
	$(DTRACE) -h -o $@ -s $<

sofs_probes.o: sofs_probes.d
	$(DTRACE) -G -o $@ -s $<

demo: demo.o sofs_probes.o
	$(CC) -o $@ $^

demo.o: demo.c sofs_probes.h
	$(CC) -c -o $@ demo.c

test: demo
	stap -I. -e 'probe sofs_* { printf("%s\n", probestr); }' -c ./demo

sofs.stp

probe sofs_chord_put = process.mark("chord_put") {
        policy = $arg1;
        length = $arg2;
        probestr = sprintf("%s(policy=%d, length=%d)", $$name, policy, length);
}

sofs_probes.d

provider sofs_probes {
        probe chord_put(int policy, int size);
};