On Fri, Nov 20, 2020 at 06:34:05PM -0800, Martin KaFai Lau wrote:
> On Thu, Nov 19, 2020 at 03:06:11PM +0000, Daniel T. Lee wrote:
> [ ... ]
>
> > static int run_bpf_prog(char *prog, int cg_id)
> > {
> > - int map_fd;
> > - int rc = 0;
> > + struct hbm_queue_stats qstats = {0};
> > + char cg_dir[100], cg_pin_path[100];
> > + struct bpf_link *link = NULL;
> > int key = 0;
> > int cg1 = 0;
> > - int type = BPF_CGROUP_INET_EGRESS;
> > - char cg_dir[100];
> > - struct hbm_queue_stats qstats = {0};
> > + int rc = 0;
> >
> > sprintf(cg_dir, "/hbm%d", cg_id);
> > - map_fd = prog_load(prog);
> > - if (map_fd == -1)
> > - return 1;
> > + rc = prog_load(prog);
> > + if (rc != 0)
> > + return rc;
> >
> > if (setup_cgroup_environment()) {
> > printf("ERROR: setting cgroup environment\n");
> > @@ -190,16 +183,25 @@ static int run_bpf_prog(char *prog, int cg_id)
> > qstats.stats = stats_flag ? 1 : 0;
> > qstats.loopback = loopback_flag ? 1 : 0;
> > qstats.no_cn = no_cn_flag ? 1 : 0;
> > - if (bpf_map_update_elem(map_fd, &key, &qstats, BPF_ANY)) {
> > + if (bpf_map_update_elem(queue_stats_fd, &key, &qstats, BPF_ANY)) {
> > printf("ERROR: Could not update map element\n");
> > goto err;
> > }
> >
> > if (!outFlag)
> > - type = BPF_CGROUP_INET_INGRESS;
> > - if (bpf_prog_attach(bpfprog_fd, cg1, type, 0)) {
> > - printf("ERROR: bpf_prog_attach fails!\n");
> > - log_err("Attaching prog");
> > + bpf_program__set_expected_attach_type(bpf_prog, BPF_CGROUP_INET_INGRESS);
> > +
> > + link = bpf_program__attach_cgroup(bpf_prog, cg1);
> > + if (libbpf_get_error(link)) {
> > + fprintf(stderr, "ERROR: bpf_program__attach_cgroup failed\n");
> > + link = NULL;
> Again, this is not needed. bpf_link__destroy() can
> handle both NULL and error pointer. Please take a look
> at the bpf_link__destroy() in libbpf.c
>
> > + goto err;
> > + }
> > +
> > + sprintf(cg_pin_path, "/sys/fs/bpf/hbm%d", cg_id);
> > + rc = bpf_link__pin(link, cg_pin_path);
> > + if (rc < 0) {
> > + printf("ERROR: bpf_link__pin failed: %d\n", rc);
> > goto err;
> > }
> >
> > @@ -213,7 +215,7 @@ static int run_bpf_prog(char *prog, int cg_id)
> > #define DELTA_RATE_CHECK 10000 /* in us */
> > #define RATE_THRESHOLD 9500000000 /* 9.5 Gbps */
> >
> > - bpf_map_lookup_elem(map_fd, &key, &qstats);
> > + bpf_map_lookup_elem(queue_stats_fd, &key, &qstats);
> > if (gettimeofday(&t0, NULL) < 0)
> > do_error("gettimeofday failed", true);
> > t_last = t0;
> > @@ -242,7 +244,7 @@ static int run_bpf_prog(char *prog, int cg_id)
> > fclose(fin);
> > printf(" new_eth_tx_bytes:%llu\n",
> > new_eth_tx_bytes);
> > - bpf_map_lookup_elem(map_fd, &key, &qstats);
> > + bpf_map_lookup_elem(queue_stats_fd, &key, &qstats);
> > new_cg_tx_bytes = qstats.bytes_total;
> > delta_bytes = new_eth_tx_bytes - last_eth_tx_bytes;
> > last_eth_tx_bytes = new_eth_tx_bytes;
> > @@ -289,14 +291,14 @@ static int run_bpf_prog(char *prog, int cg_id)
> > rate = minRate;
> > qstats.rate = rate;
> > }
> > - if (bpf_map_update_elem(map_fd, &key, &qstats, BPF_ANY))
> > + if (bpf_map_update_elem(queue_stats_fd, &key, &qstats, BPF_ANY))
> > do_error("update map element fails", false);
> > }
> > } else {
> > sleep(dur);
> > }
> > // Get stats!
> > - if (stats_flag && bpf_map_lookup_elem(map_fd, &key, &qstats)) {
> > + if (stats_flag && bpf_map_lookup_elem(queue_stats_fd, &key, &qstats)) {
> > char fname[100];
> > FILE *fout;
> >
> > @@ -398,10 +400,10 @@ static int run_bpf_prog(char *prog, int cg_id)
> > err:
> > rc = 1;
> >
> > - if (cg1)
> > - close(cg1);
> > + bpf_link__destroy(link);
> > + close(cg1);
> > cleanup_cgroup_environment();
> > -
> > + bpf_object__close(obj);
> The bpf_* cleanup condition still looks wrong.
>
> I can understand why it does not want to cleanup_cgroup_environment()
> on the success case because the sh script may want to run test under this
> cgroup.
>
> However, the bpf_link__destroy(), bpf_object__close(), and
> even close(cg1) should be done in both success and error
> cases.
>
> The cg1 test still looks wrong also. The cg1 should
> be init to -1 and then test for "if (cg1 == -1)".
oops. I meant cg1 != -1 .
