# args
sudo cat /sys/kernel/tracing/events/syscalls/sys_enter_write/format
bpftrace -lv 'kfunc:foo'
# exposed headers
# /usr/src/linux-headers-6.1.0-35-common/include/linux/sched.h
# => #include <linux/sched.h>
# Trace libc calls
# - /!\ need to scope glob, use dynamic syms: ~/bin/libctrace.sh
bpftrace -e '
BEGIN { @start = nsecs; }
uprobe:/usr/lib64/libc-2.33.so:* /@start != 0 && pid == cpid/ {
printf("%-08d %-04d %s\n", tid, (nsecs - @start) / 1000000, func);
}' -c '/bin/sleep 2'
# Trace user functions
bpftrace -e 'uprobe:/bin/bash:readline {
printf("%s\n", ustack(perf, 10));
}'
# C++
readelf -Ws /foo | grep methodName
#69: 00000000004007ee 30 FUNC WEAK DEFAULT 14 _ZN6BigApp10methodNameEv
bpftrace -e 'uprobe:/foo:_ZN6BigApp10methodNameEv { printf("1"); }'
bpftrace -e 'uprobe:/foo:"function signature" { printf("1"); }'# Files opened by process
bpftrace -e 'tracepoint:syscalls:sys_enter_open { printf("%s %s\n", comm, str(args->filename)); }'
# Syscall count by program
bpftrace -e 'tracepoint:raw_syscalls:sys_enter { @[comm] = count(); }'
# Read bytes by process:
bpftrace -e 'tracepoint:syscalls:sys_exit_read /args->ret/ { @[comm] = sum(args->ret); }'
# Read size distribution by process:
bpftrace -e 'tracepoint:syscalls:sys_exit_read { @[comm] = hist(args->ret); }'
# Show per-second syscall rates:
bpftrace -e 'tracepoint:raw_syscalls:sys_enter { @ = count(); } interval:s:1 { print(@); clear(@); }'
# Trace disk size by process
bpftrace -e 'tracepoint:block:block_rq_issue { printf("%d %s %d\n", pid, comm, args->bytes); }'
# Count page faults by process
bpftrace -e 'software:faults:1 { @[comm] = count(); }'
# Count LLC cache misses by process name and PID (uses PMCs):
bpftrace -e 'hardware:cache-misses:1000000 { @[comm, pid] = count(); }'
# Profile user-level stacks at 99 Hertz, for PID 189:
bpftrace -e 'profile:hz:99 /pid == 189/ { @[ustack] = count(); }'
# Files opened, for processes in the root cgroup-v2
bpftrace -e 'tracepoint:syscalls:sys_enter_openat /cgroup == cgroupid("/sys/fs/cgroup/unified/mycg")/ { printf("%s\n", str(args->filename)); }'