[PATCH bpf-next v4 11/22] samples: bpf: Add devmap_xmit tracepoint statistics support
From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: 2021-08-21 00:21:05
Also in:
netdev
Subsystem:
bpf [general] (safe dynamic programs and tools), the rest, xdp (express data path) · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds, David S. Miller, Jakub Kicinski, Jesper Dangaard Brouer, John Fastabend
This adds support for retrieval and printing for devmap_xmit total and mutli mode tracepoint. For multi mode, we keep a hash map entry for each redirection stream, such that we can dynamically add and remove entries on output. The from_match and to_match will be set by individual samples when setting up the XDP program on these devices. The multi mode tracepoint is also handy for xdp_redirect_map_multi, where up to 32 devices can be specified. Also add samples_init_pre_load macro to finally set up the resized maps and mmap them in place for low overhead stats retrieval. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> --- samples/bpf/xdp_sample_user.c | 317 +++++++++++++++++++++++++++++++++- samples/bpf/xdp_sample_user.h | 17 ++ 2 files changed, 331 insertions(+), 3 deletions(-)
diff --git a/samples/bpf/xdp_sample_user.c b/samples/bpf/xdp_sample_user.c
index e2692dee1dbb..eb484c15492d 100644
--- a/samples/bpf/xdp_sample_user.c
+++ b/samples/bpf/xdp_sample_user.c@@ -77,6 +77,8 @@ enum map_type { MAP_CPUMAP_ENQUEUE, MAP_CPUMAP_KTHREAD, MAP_EXCEPTION, + MAP_DEVMAP_XMIT, + MAP_DEVMAP_XMIT_MULTI, NUM_MAP, };
@@ -103,6 +105,8 @@ struct stats_record { struct record redir_err[XDP_REDIRECT_ERR_MAX]; struct record kthread; struct record exception[XDP_ACTION_MAX]; + struct record devmap_xmit; + DECLARE_HASHTABLE(xmit_map, 5); struct record enq[]; };
@@ -111,7 +115,9 @@ struct sample_output { __u64 rx; __u64 redir; __u64 drop; + __u64 drop_xmit; __u64 err; + __u64 xmit; } totals; struct { __u64 pps;
@@ -125,6 +131,12 @@ struct sample_output { struct { __u64 hits; } except_cnt; + struct { + __u64 pps; + __u64 drop; + __u64 err; + double bavg; + } xmit_cnt; }; struct xdp_desc {
@@ -265,6 +277,16 @@ static void sample_print_help(int mask) " \t\t\t\thit/s - Number of times the tracepoint was hit per second\n\n"); } + if (mask & SAMPLE_DEVMAP_XMIT_CNT) { + printf(" devmap_xmit\t\tDisplays devmap_xmit tracepoint events\n" + " \t\t\tThis tracepoint is invoked for successful transmissions on output\n" + " \t\t\tdevice but these statistics are not available for generic XDP mode,\n" + " \t\t\thence they will be omitted from the output when using SKB mode\n" + " \t\t\t\txmit/s - Number of packets that were transmitted per second\n" + " \t\t\t\tdrop/s - Number of packets that failed transmissions per second\n" + " \t\t\t\tdrv_err/s - Number of internal driver errors per second\n" + " \t\t\t\tbulk-avg - Average number of packets processed for each event\n\n"); + } } void sample_usage(char *argv[], const struct option *long_options,
@@ -353,6 +375,74 @@ static void map_collect_percpu(struct datarec *values, struct record *rec) rec->total.xdp_redirect = sum_xdp_redirect; } +static int map_collect_percpu_devmap(int map_fd, struct stats_record *rec) +{ + unsigned int nr_cpus = bpf_num_possible_cpus(); + __u32 batch, count = 32; + struct datarec *values; + bool init = false; + __u64 *keys; + int i, ret; + + keys = calloc(count, sizeof(__u64)); + if (!keys) + return -ENOMEM; + values = calloc(count * nr_cpus, sizeof(struct datarec)); + if (!values) { + free(keys); + return -ENOMEM; + } + + for (;;) { + bool exit = false; + + ret = bpf_map_lookup_batch(map_fd, init ? &batch : NULL, &batch, + keys, values, &count, NULL); + if (ret < 0 && errno != ENOENT) + break; + if (errno == ENOENT) + exit = true; + + init = true; + for (i = 0; i < count; i++) { + struct map_entry *e, *x = NULL; + __u64 pair = keys[i]; + struct datarec *arr; + + arr = &values[i * nr_cpus]; + hash_for_each_possible(rec->xmit_map, e, node, pair) { + if (e->pair == pair) { + x = e; + break; + } + } + if (!x) { + x = calloc(1, sizeof(*x)); + if (!x) + goto cleanup; + if (map_entry_init(x, pair) < 0) { + free(x); + goto cleanup; + } + hash_add(rec->xmit_map, &x->node, pair); + } + map_collect_percpu(arr, &x->val); + } + + if (exit) + break; + count = 32; + } + + free(values); + free(keys); + return 0; +cleanup: + free(values); + free(keys); + return -ENOMEM; +} + static struct stats_record *alloc_stats_record(void) { struct stats_record *rec;
@@ -408,6 +498,16 @@ static struct stats_record *alloc_stats_record(void) } } } + if (sample_mask & SAMPLE_DEVMAP_XMIT_CNT) { + rec->devmap_xmit.cpu = alloc_record_per_cpu(); + if (!rec->devmap_xmit.cpu) { + fprintf(stderr, + "Failed to allocate devmap_xmit per-CPU array\n"); + goto end_exception; + } + } + if (sample_mask & SAMPLE_DEVMAP_XMIT_CNT_MULTI) + hash_init(rec->xmit_map); if (sample_mask & SAMPLE_CPUMAP_ENQUEUE_CNT) { for (i = 0; i < sample_n_cpus; i++) { rec->enq[i].cpu = alloc_record_per_cpu();
@@ -418,13 +518,15 @@ static struct stats_record *alloc_stats_record(void) i); while (i--) free(rec->enq[i].cpu); - goto end_exception; + goto end_devmap_xmit; } } } return rec; +end_devmap_xmit: + free(rec->devmap_xmit.cpu); end_exception: for (i = 0; i < XDP_ACTION_MAX; i++) free(rec->exception[i].cpu);
@@ -448,6 +550,12 @@ static void free_stats_record(struct stats_record *r) for (i = 0; i < sample_n_cpus; i++) free(r->enq[i].cpu); + hash_for_each_safe(r->xmit_map, i, tmp, e, node) { + hash_del(&e->node); + free(e->val.cpu); + free(e); + } + free(r->devmap_xmit.cpu); for (i = 0; i < XDP_ACTION_MAX; i++) free(r->exception[i].cpu); free(r->kthread.cpu);
@@ -835,6 +943,160 @@ static void stats_get_exception_cnt(struct stats_record *stats_rec, } } +static void stats_get_devmap_xmit(struct stats_record *stats_rec, + struct stats_record *stats_prev, + unsigned int nr_cpus, + struct sample_output *out) +{ + double pps, drop, info, err; + struct record *rec, *prev; + double t; + int i; + + rec = &stats_rec->devmap_xmit; + prev = &stats_prev->devmap_xmit; + t = calc_period(rec, prev); + for (i = 0; i < nr_cpus; i++) { + struct datarec *r = &rec->cpu[i]; + struct datarec *p = &prev->cpu[i]; + char str[64]; + + pps = calc_pps(r, p, t); + drop = calc_drop_pps(r, p, t); + err = calc_errs_pps(r, p, t); + + if (!pps && !drop && !err) + continue; + + snprintf(str, sizeof(str), "cpu:%d", i); + info = calc_info_pps(r, p, t); + if (info > 0) + info = (pps + drop) / info; /* calc avg bulk */ + print_default(" %-18s" FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf + __COLUMN(".2f") "\n", + str, XMIT(pps), DROP(drop), err, "drv_err/s", + info, "bulk-avg"); + } + if (out) { + pps = calc_pps(&rec->total, &prev->total, t); + drop = calc_drop_pps(&rec->total, &prev->total, t); + info = calc_info_pps(&rec->total, &prev->total, t); + if (info > 0) + info = (pps + drop) / info; /* calc avg bulk */ + err = calc_errs_pps(&rec->total, &prev->total, t); + + out->xmit_cnt.pps = pps; + out->xmit_cnt.drop = drop; + out->xmit_cnt.bavg = info; + out->xmit_cnt.err = err; + out->totals.xmit += pps; + out->totals.drop_xmit += drop; + out->totals.err += err; + } +} + +static void stats_get_devmap_xmit_multi(struct stats_record *stats_rec, + struct stats_record *stats_prev, + unsigned int nr_cpus, + struct sample_output *out, + bool xmit_total) +{ + double pps, drop, info, err; + struct map_entry *entry; + struct record *r, *p; + double t; + int bkt; + + hash_for_each(stats_rec->xmit_map, bkt, entry, node) { + struct map_entry *e, *x = NULL; + char ifname_from[IFNAMSIZ]; + char ifname_to[IFNAMSIZ]; + const char *fstr, *tstr; + unsigned long prev_time; + struct record beg = {}; + __u32 from_idx, to_idx; + char str[128]; + __u64 pair; + int i; + + prev_time = sample_interval * NANOSEC_PER_SEC; + + pair = entry->pair; + from_idx = pair >> 32; + to_idx = pair & 0xFFFFFFFF; + + r = &entry->val; + beg.timestamp = r->timestamp - prev_time; + + /* Find matching entry from stats_prev map */ + hash_for_each_possible(stats_prev->xmit_map, e, node, pair) { + if (e->pair == pair) { + x = e; + break; + } + } + if (x) + p = &x->val; + else + p = &beg; + t = calc_period(r, p); + pps = calc_pps(&r->total, &p->total, t); + drop = calc_drop_pps(&r->total, &p->total, t); + info = calc_info_pps(&r->total, &p->total, t); + if (info > 0) + info = (pps + drop) / info; /* calc avg bulk */ + err = calc_errs_pps(&r->total, &p->total, t); + + if (out) { + /* We are responsible for filling out totals */ + out->totals.xmit += pps; + out->totals.drop_xmit += drop; + out->totals.err += err; + continue; + } + + fstr = tstr = NULL; + if (if_indextoname(from_idx, ifname_from)) + fstr = ifname_from; + if (if_indextoname(to_idx, ifname_to)) + tstr = ifname_to; + + snprintf(str, sizeof(str), "xmit %s->%s", fstr ?: "?", + tstr ?: "?"); + /* Skip idle streams of redirection */ + if (pps || drop || err) { + print_err(drop, + " %-20s " FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf + __COLUMN(".2f") "\n", str, XMIT(pps), DROP(drop), + err, "drv_err/s", info, "bulk-avg"); + } + + for (i = 0; i < nr_cpus; i++) { + struct datarec *rc = &r->cpu[i]; + struct datarec *pc, p_beg = {}; + char str[64]; + + pc = p == &beg ? &p_beg : &p->cpu[i]; + + pps = calc_pps(rc, pc, t); + drop = calc_drop_pps(rc, pc, t); + err = calc_errs_pps(rc, pc, t); + + if (!pps && !drop && !err) + continue; + + snprintf(str, sizeof(str), "cpu:%d", i); + info = calc_info_pps(rc, pc, t); + if (info > 0) + info = (pps + drop) / info; /* calc avg bulk */ + + print_default(" %-18s" FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf + __COLUMN(".2f") "\n", str, XMIT(pps), + DROP(drop), err, "drv_err/s", info, "bulk-avg"); + } + } +} + static void stats_print(const char *prefix, int mask, struct stats_record *r, struct stats_record *p, struct sample_output *out) {
@@ -849,6 +1111,9 @@ static void stats_print(const char *prefix, int mask, struct stats_record *r, printf(FMT_COLUMNl, out->totals.err + out->totals.drop + out->totals.drop_xmit, "err,drop/s"); + if (mask & SAMPLE_DEVMAP_XMIT_CNT || + mask & SAMPLE_DEVMAP_XMIT_CNT_MULTI) + printf(FMT_COLUMNl, XMIT(out->totals.xmit)); printf("\n"); if (mask & SAMPLE_RX_CNT) {
@@ -899,6 +1164,25 @@ static void stats_print(const char *prefix, int mask, struct stats_record *r, stats_get_exception_cnt(r, p, nr_cpus, NULL); } + if (mask & SAMPLE_DEVMAP_XMIT_CNT) { + str = (sample_log_level & LL_DEFAULT) && out->xmit_cnt.pps ? + "devmap_xmit total" : + "devmap_xmit"; + + print_err(out->xmit_cnt.err || out->xmit_cnt.drop, + " %-20s " FMT_COLUMNl FMT_COLUMNl FMT_COLUMNl + __COLUMN(".2f") "\n", + str, XMIT(out->xmit_cnt.pps), + DROP(out->xmit_cnt.drop), out->xmit_cnt.err, + "drv_err/s", out->xmit_cnt.bavg, "bulk-avg"); + + stats_get_devmap_xmit(r, p, nr_cpus, NULL); + } + + if (mask & SAMPLE_DEVMAP_XMIT_CNT_MULTI) + stats_get_devmap_xmit_multi(r, p, nr_cpus, NULL, + mask & SAMPLE_DEVMAP_XMIT_CNT); + if (sample_log_level & LL_DEFAULT || ((sample_log_level & LL_SIMPLE) && sample_err_exp)) { sample_err_exp = false;
@@ -910,12 +1194,13 @@ int sample_setup_maps(struct bpf_map **maps) { sample_n_cpus = libbpf_num_possible_cpus(); - for (int i = 0; i < NUM_MAP; i++) { + for (int i = 0; i < MAP_DEVMAP_XMIT_MULTI; i++) { sample_map[i] = maps[i]; switch (i) { case MAP_RX: case MAP_CPUMAP_KTHREAD: + case MAP_DEVMAP_XMIT: sample_map_count[i] = sample_n_cpus; break; case MAP_REDIRECT_ERR:
@@ -933,12 +1218,13 @@ int sample_setup_maps(struct bpf_map **maps) if (bpf_map__resize(sample_map[i], sample_map_count[i]) < 0) return -errno; } + sample_map[MAP_DEVMAP_XMIT_MULTI] = maps[MAP_DEVMAP_XMIT_MULTI]; return 0; } static int sample_setup_maps_mappings(void) { - for (int i = 0; i < NUM_MAP; i++) { + for (int i = 0; i < MAP_DEVMAP_XMIT_MULTI; i++) { size_t size = sample_map_count[i] * sizeof(struct datarec); sample_mmap[i] = mmap(NULL, size, PROT_READ | PROT_WRITE,
@@ -1057,9 +1343,20 @@ static void sample_summary_print(void) if (sample_out.totals.drop) print_always(" Rx dropped : %'-10llu\n", sample_out.totals.drop); + if (sample_out.totals.drop_xmit) + print_always(" Tx dropped : %'-10llu\n", + sample_out.totals.drop_xmit); if (sample_out.totals.err) print_always(" Errors recorded : %'-10llu\n", sample_out.totals.err); + if (sample_out.totals.xmit) { + double pkts = sample_out.totals.xmit; + + print_always(" Packets transmitted : %'-10llu\n", + sample_out.totals.xmit); + print_always(" Average transmit/s : %'-10.0f\n", + sample_round(pkts / period)); + } } void sample_exit(int status)
@@ -1115,6 +1412,13 @@ static int sample_stats_collect(struct stats_record *rec) map_collect_percpu(&sample_mmap[MAP_EXCEPTION][i * sample_n_cpus], &rec->exception[i]); + if (sample_mask & SAMPLE_DEVMAP_XMIT_CNT) + map_collect_percpu(sample_mmap[MAP_DEVMAP_XMIT], &rec->devmap_xmit); + + if (sample_mask & SAMPLE_DEVMAP_XMIT_CNT_MULTI) { + if (map_collect_percpu_devmap(bpf_map__fd(sample_map[MAP_DEVMAP_XMIT_MULTI]), rec) < 0) + return -EINVAL; + } return 0; }
@@ -1123,7 +1427,9 @@ static void sample_summary_update(struct sample_output *out, int interval) sample_out.totals.rx += out->totals.rx; sample_out.totals.redir += out->totals.redir; sample_out.totals.drop += out->totals.drop; + sample_out.totals.drop_xmit += out->totals.drop_xmit; sample_out.totals.err += out->totals.err; + sample_out.totals.xmit += out->totals.xmit; sample_out.rx_cnt.pps += interval; }
@@ -1141,6 +1447,11 @@ static void sample_stats_print(int mask, struct stats_record *cur, stats_get_redirect_err_cnt(cur, prev, 0, &out); if (mask & SAMPLE_EXCEPTION_CNT) stats_get_exception_cnt(cur, prev, 0, &out); + if (mask & SAMPLE_DEVMAP_XMIT_CNT) + stats_get_devmap_xmit(cur, prev, 0, &out); + else if (mask & SAMPLE_DEVMAP_XMIT_CNT_MULTI) + stats_get_devmap_xmit_multi(cur, prev, 0, &out, + mask & SAMPLE_DEVMAP_XMIT_CNT); sample_summary_update(&out, interval); stats_print(prog_name, mask, cur, prev, &out);
diff --git a/samples/bpf/xdp_sample_user.h b/samples/bpf/xdp_sample_user.h
index 203732615fee..3a678986cce2 100644
--- a/samples/bpf/xdp_sample_user.h
+++ b/samples/bpf/xdp_sample_user.h@@ -14,9 +14,11 @@ enum stats_mask { SAMPLE_CPUMAP_ENQUEUE_CNT = 1U << 3, SAMPLE_CPUMAP_KTHREAD_CNT = 1U << 4, SAMPLE_EXCEPTION_CNT = 1U << 5, + SAMPLE_DEVMAP_XMIT_CNT = 1U << 6, SAMPLE_REDIRECT_CNT = 1U << 7, SAMPLE_REDIRECT_MAP_CNT = SAMPLE_REDIRECT_CNT | _SAMPLE_REDIRECT_MAP, SAMPLE_REDIRECT_ERR_MAP_CNT = SAMPLE_REDIRECT_ERR_CNT | _SAMPLE_REDIRECT_MAP, + SAMPLE_DEVMAP_XMIT_CNT_MULTI = 1U << 8, }; /* Exit return codes */
@@ -63,6 +65,17 @@ static inline char *safe_strncpy(char *dst, const char *src, size_t size) return -errno; \ }) +#define sample_init_pre_load(skel) \ + ({ \ + skel->rodata->nr_cpus = libbpf_num_possible_cpus(); \ + sample_setup_maps((struct bpf_map *[]){ \ + skel->maps.rx_cnt, skel->maps.redir_err_cnt, \ + skel->maps.cpumap_enqueue_cnt, \ + skel->maps.cpumap_kthread_cnt, \ + skel->maps.exception_cnt, skel->maps.devmap_xmit_cnt, \ + skel->maps.devmap_xmit_cnt_multi }); \ + }) + #define DEFINE_SAMPLE_INIT(name) \ static int sample_init(struct name *skel, int mask) \ { \
@@ -84,6 +97,10 @@ static inline char *safe_strncpy(char *dst, const char *src, size_t size) __attach_tp(tp_xdp_cpumap_kthread); \ if (mask & SAMPLE_EXCEPTION_CNT) \ __attach_tp(tp_xdp_exception); \ + if (mask & SAMPLE_DEVMAP_XMIT_CNT) \ + __attach_tp(tp_xdp_devmap_xmit); \ + if (mask & SAMPLE_DEVMAP_XMIT_CNT_MULTI) \ + __attach_tp(tp_xdp_devmap_xmit_multi); \ return 0; \ }
--
2.33.0