Libbpf eBPF macro __noinline

v0.2

The __noinline macros is used to tell the compiler to inline a function.

Definition

#define __noinline __attribute__((noinline))

Usage

This macro is used to tell the compiler to not inline a function. This is mainly useful to force the use of a BPF-to-BPF function call. This might be important if you are at the limit of stack space in calling functions.

Example

static int __noinline add(int a, int b)
{
    return a + b;
}

SEC("xdp")
int example_prog(struct xdp_md *ctx)
{
    if (add(1, 2) == 3)
        return XDP_PASS;
    else
        return XDP_DROP;
}