fn initialize_bpf()

in src/samplers/scheduler/mod.rs [322:371]

• 39 lines of code
• 11 McCabe index (conditional complexity)

    fn initialize_bpf(&mut self) -> Result<(), anyhow::Error> {
        #[cfg(feature = "bpf")]
        {
            if self.enabled() && self.bpf_enabled() {
                debug!("initializing bpf");

                // get info about the running kernel
                let kernel_info = KernelInfo::new()?;
                let kernel_major = kernel_info.release_major()?;
                let kernel_minor = kernel_info.release_minor()?;

                // load the code and compile
                let code = include_str!("bpf.c");
                let code = code.replace(
                    "VALUE_TO_INDEX2_FUNC",
                    include_str!("../../common/value_to_index2.c"),
                );
                // task_struct changes in kernel 5.14
                let code = if kernel_major > 5 || (kernel_major == 5 && kernel_minor >= 14) {
                    code.replace("STATE_FIELD", "__state")
                } else {
                    code.replace("STATE_FIELD", "state")
                };
                let mut bpf = bcc::BPF::new(&code)?;

                // collect the set of probes required from the statistics enabled.
                let mut probes = HashSet::new();
                for statistic in &self.statistics {
                    for probe in statistic.bpf_probes_required() {
                        probes.insert(probe);
                    }
                }

                // load + attach the kernel probes that are required to the bpf instance.
                for probe in probes {
                    if self.common.config.fault_tolerant() {
                        if let Err(e) = probe.try_attach_to_bpf(&mut bpf) {
                            warn!("skipping {} with error: {}", probe.name, e);
                        }
                    } else {
                        probe.try_attach_to_bpf(&mut bpf)?;
                    }
                }

                self.bpf = Some(Arc::new(Mutex::new(BPF { inner: bpf })));
            }
        }

        Ok(())
    }