From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: Sat, 21 Aug 2021 05:49:59 +0530
Subject: samples: bpf: Add devmap_xmit tracepoint statistics support
Patch-mainline: v5.15-rc1
Git-commit: af93d58c27b6ac4154f1651f47be2a159f8ce30f
References: jsc#PED-1377
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>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-12-memxor@gmail.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
samples/bpf/xdp_sample_user.c | 317 +++++++++++++++++++++++++++++++++++++++++-
samples/bpf/xdp_sample_user.h | 17 ++
2 files changed, 331 insertions(+), 3 deletions(-)
--- 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 da
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_
}
}
}
+ 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_
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 sta
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(stru
}
}
+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 *pref
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 *pref
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 **m
{
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 **m
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 s
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_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,
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);
--- 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 *d
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 *d
__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; \
}