Skip to content

Commit

Permalink
samples: bpf: Add cpumap tracepoint statistics support
Browse files Browse the repository at this point in the history 
This consolidates retrieval and printing into the XDP sample helper. For
the kthread stats, it expands xdp_stats separately with its own per-CPU
stats. For cpumap enqueue, we display FROM->TO stats also with its
per-CPU stats.

The help out explains in detail the various aspects of the output.

Signed-off-by: Kumar Kartikeya Dwivedi <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
  • Loading branch information
@kkdwivedi
kkdwivedi authored and Alexei Starovoitov committed Aug 24, 2021
1 parent 0cf3c2f commit d771e21
Show file tree
Hide file tree
Showing 2 changed files with 224 additions and 1 deletion.
219 changes: 218 additions & 1 deletion samples/bpf/xdp_sample_user.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -74,6 +74,8 @@
enum map_type {
MAP_RX,
MAP_REDIRECT_ERR,
MAP_CPUMAP_ENQUEUE,
MAP_CPUMAP_KTHREAD,
MAP_EXCEPTION,
NUM_MAP,
};
Expand All @@ -99,13 +101,16 @@ struct map_entry {
struct stats_record {
struct record rx_cnt;
struct record redir_err[XDP_REDIRECT_ERR_MAX];
struct record kthread;
struct record exception[XDP_ACTION_MAX];
struct record enq[];
};

struct sample_output {
struct {
__u64 rx;
__u64 redir;
__u64 drop;
__u64 err;
} totals;
struct {
Expand Down Expand Up @@ -228,6 +233,30 @@ static void sample_print_help(int mask)
printf(" \n\t\t\t\terror/s - Packets that failed redirection per second\n\n");
}

if (mask & SAMPLE_CPUMAP_ENQUEUE_CNT) {
printf(" enqueue to cpu N\tDisplays the number of packets enqueued to bulk queue of CPU N\n"
" \t\t\tExpands to cpu:FROM->N to display enqueue stats for each CPU enqueuing to CPU N\n"
" \t\t\tReceived packets can be associated with the CPU redirect program is enqueuing \n"
" \t\t\tpackets to.\n"
" \t\t\t\tpkt/s - Packets enqueued per second from other CPU to CPU N\n"
" \t\t\t\tdrop/s - Packets dropped when trying to enqueue to CPU N\n"
" \t\t\t\tbulk-avg - Average number of packets processed for each event\n\n");
}

if (mask & SAMPLE_CPUMAP_KTHREAD_CNT) {
printf(" kthread\t\tDisplays the number of packets processed in CPUMAP kthread for each CPU\n"
" \t\t\tPackets consumed from ptr_ring in kthread, and its xdp_stats (after calling \n"
" \t\t\tCPUMAP bpf prog) are expanded below this. xdp_stats are expanded as a total and\n"
" \t\t\tthen per-CPU to associate it to each CPU's pinned CPUMAP kthread.\n"
" \t\t\t\tpkt/s - Packets consumed per second from ptr_ring\n"
" \t\t\t\tdrop/s - Packets dropped per second in kthread\n"
" \t\t\t\tsched - Number of times kthread called schedule()\n\n"
" \t\t\txdp_stats (also expands to per-CPU counts)\n"
" \t\t\t\tpass/s - XDP_PASS count for CPUMAP program execution\n"
" \t\t\t\tdrop/s - XDP_DROP count for CPUMAP program execution\n"
" \t\t\t\tredir/s - XDP_REDIRECT count for CPUMAP program execution\n\n");
}

if (mask & SAMPLE_EXCEPTION_CNT) {
printf(" xdp_exception\t\tDisplays xdp_exception tracepoint events\n"
" \t\t\tThis can occur due to internal driver errors, unrecognized\n"
Expand Down Expand Up @@ -357,6 +386,14 @@ static struct stats_record *alloc_stats_record(void)
}
}
}
if (sample_mask & SAMPLE_CPUMAP_KTHREAD_CNT) {
rec->kthread.cpu = alloc_record_per_cpu();
if (!rec->kthread.cpu) {
fprintf(stderr,
"Failed to allocate kthread per-CPU array\n");
goto end_redir;
}
}
if (sample_mask & SAMPLE_EXCEPTION_CNT) {
for (i = 0; i < XDP_ACTION_MAX; i++) {
rec->exception[i].cpu = alloc_record_per_cpu();
Expand All @@ -367,13 +404,32 @@ static struct stats_record *alloc_stats_record(void)
action2str(i));
while (i--)
free(rec->exception[i].cpu);
goto end_redir;
goto end_kthread;
}
}
}
if (sample_mask & SAMPLE_CPUMAP_ENQUEUE_CNT) {
for (i = 0; i < sample_n_cpus; i++) {
rec->enq[i].cpu = alloc_record_per_cpu();
if (!rec->enq[i].cpu) {
fprintf(stderr,
"Failed to allocate enqueue per-CPU array for "
"CPU %d\n",
i);
while (i--)
free(rec->enq[i].cpu);
goto end_exception;
}
}
}

return rec;

end_exception:
for (i = 0; i < XDP_ACTION_MAX; i++)
free(rec->exception[i].cpu);
end_kthread:
free(rec->kthread.cpu);
end_redir:
for (i = 0; i < XDP_REDIRECT_ERR_MAX; i++)
free(rec->redir_err[i].cpu);
Expand All @@ -390,8 +446,11 @@ static void free_stats_record(struct stats_record *r)
struct map_entry *e;
int i;

for (i = 0; i < sample_n_cpus; i++)
free(r->enq[i].cpu);
for (i = 0; i < XDP_ACTION_MAX; i++)
free(r->exception[i].cpu);
free(r->kthread.cpu);
for (i = 0; i < XDP_REDIRECT_ERR_MAX; i++)
free(r->redir_err[i].cpu);
free(r->rx_cnt.cpu);
Expand Down Expand Up @@ -519,6 +578,137 @@ static void stats_get_rx_cnt(struct stats_record *stats_rec,
}
}

static void stats_get_cpumap_enqueue(struct stats_record *stats_rec,
struct stats_record *stats_prev,
unsigned int nr_cpus)
{
struct record *rec, *prev;
double t, pps, drop, err;
int i, to_cpu;

/* cpumap enqueue stats */
for (to_cpu = 0; to_cpu < sample_n_cpus; to_cpu++) {
rec = &stats_rec->enq[to_cpu];
prev = &stats_prev->enq[to_cpu];
t = calc_period(rec, prev);

pps = calc_pps(&rec->total, &prev->total, t);
drop = calc_drop_pps(&rec->total, &prev->total, t);
err = calc_errs_pps(&rec->total, &prev->total, t);

if (pps > 0 || drop > 0) {
char str[64];

snprintf(str, sizeof(str), "enqueue to cpu %d", to_cpu);

if (err > 0)
err = pps / err; /* calc average bulk size */

print_err(drop,
" %-20s " FMT_COLUMNf FMT_COLUMNf __COLUMN(
".2f") "\n",
str, PPS(pps), DROP(drop), err, "bulk-avg");
}

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->%d", i, to_cpu);
if (err > 0)
err = pps / err; /* calc average bulk size */
print_default(
" %-18s " FMT_COLUMNf FMT_COLUMNf __COLUMN(
".2f") "\n",
str, PPS(pps), DROP(drop), err, "bulk-avg");
}
}
}

static void stats_get_cpumap_remote(struct stats_record *stats_rec,
struct stats_record *stats_prev,
unsigned int nr_cpus)
{
double xdp_pass, xdp_drop, xdp_redirect;
struct record *rec, *prev;
double t;
int i;

rec = &stats_rec->kthread;
prev = &stats_prev->kthread;
t = calc_period(rec, prev);

calc_xdp_pps(&rec->total, &prev->total, &xdp_pass, &xdp_drop,
&xdp_redirect, t);
if (xdp_pass || xdp_drop || xdp_redirect) {
print_err(xdp_drop,
" %-18s " FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf "\n",
"xdp_stats", PASS(xdp_pass), DROP(xdp_drop),
REDIR(xdp_redirect));
}

for (i = 0; i < nr_cpus; i++) {
struct datarec *r = &rec->cpu[i];
struct datarec *p = &prev->cpu[i];
char str[64];

calc_xdp_pps(r, p, &xdp_pass, &xdp_drop, &xdp_redirect, t);
if (!xdp_pass && !xdp_drop && !xdp_redirect)
continue;

snprintf(str, sizeof(str), "cpu:%d", i);
print_default(" %-16s " FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf
"\n",
str, PASS(xdp_pass), DROP(xdp_drop),
REDIR(xdp_redirect));
}
}

static void stats_get_cpumap_kthread(struct stats_record *stats_rec,
struct stats_record *stats_prev,
unsigned int nr_cpus)
{
struct record *rec, *prev;
double t, pps, drop, err;
int i;

rec = &stats_rec->kthread;
prev = &stats_prev->kthread;
t = calc_period(rec, prev);

pps = calc_pps(&rec->total, &prev->total, t);
drop = calc_drop_pps(&rec->total, &prev->total, t);
err = calc_errs_pps(&rec->total, &prev->total, t);

print_err(drop, " %-20s " FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf "\n",
pps ? "kthread total" : "kthread", PPS(pps), DROP(drop), err,
"sched");

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);
print_default(" %-18s " FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf
"\n",
str, PPS(pps), DROP(drop), err, "sched");
}
}

static void stats_get_redirect_cnt(struct stats_record *stats_rec,
struct stats_record *stats_prev,
unsigned int nr_cpus,
Expand Down Expand Up @@ -656,6 +846,9 @@ static void stats_print(const char *prefix, int mask, struct stats_record *r,
print_always(FMT_COLUMNl, RX(out->totals.rx));
if (mask & SAMPLE_REDIRECT_CNT)
print_always(FMT_COLUMNl, REDIR(out->totals.redir));
printf(FMT_COLUMNl,
out->totals.err + out->totals.drop + out->totals.drop_xmit,
"err,drop/s");
printf("\n");

if (mask & SAMPLE_RX_CNT) {
Expand All @@ -670,6 +863,14 @@ static void stats_print(const char *prefix, int mask, struct stats_record *r,
stats_get_rx_cnt(r, p, nr_cpus, NULL);
}

if (mask & SAMPLE_CPUMAP_ENQUEUE_CNT)
stats_get_cpumap_enqueue(r, p, nr_cpus);

if (mask & SAMPLE_CPUMAP_KTHREAD_CNT) {
stats_get_cpumap_kthread(r, p, nr_cpus);
stats_get_cpumap_remote(r, p, nr_cpus);
}

if (mask & SAMPLE_REDIRECT_CNT) {
str = out->redir_cnt.suc ? "redirect total" : "redirect";
print_default(" %-20s " FMT_COLUMNl "\n", str,
Expand Down Expand Up @@ -714,6 +915,7 @@ int sample_setup_maps(struct bpf_map **maps)

switch (i) {
case MAP_RX:
case MAP_CPUMAP_KTHREAD:
sample_map_count[i] = sample_n_cpus;
break;
case MAP_REDIRECT_ERR:
Expand All @@ -722,6 +924,8 @@ int sample_setup_maps(struct bpf_map **maps)
break;
case MAP_EXCEPTION:
sample_map_count[i] = XDP_ACTION_MAX * sample_n_cpus;
case MAP_CPUMAP_ENQUEUE:
sample_map_count[i] = sample_n_cpus * sample_n_cpus;
break;
default:
return -EINVAL;
Expand Down Expand Up @@ -850,6 +1054,9 @@ static void sample_summary_print(void)
print_always(" Average redir/s : %'-10.0f\n",
sample_round(pkts / period));
}
if (sample_out.totals.drop)
print_always(" Rx dropped : %'-10llu\n",
sample_out.totals.drop);
if (sample_out.totals.err)
print_always(" Errors recorded : %'-10llu\n",
sample_out.totals.err);
Expand Down Expand Up @@ -894,6 +1101,15 @@ static int sample_stats_collect(struct stats_record *rec)
&rec->redir_err[i]);
}

if (sample_mask & SAMPLE_CPUMAP_ENQUEUE_CNT)
for (i = 0; i < sample_n_cpus; i++)
map_collect_percpu(&sample_mmap[MAP_CPUMAP_ENQUEUE][i * sample_n_cpus],
&rec->enq[i]);

if (sample_mask & SAMPLE_CPUMAP_KTHREAD_CNT)
map_collect_percpu(sample_mmap[MAP_CPUMAP_KTHREAD],
&rec->kthread);

if (sample_mask & SAMPLE_EXCEPTION_CNT)
for (i = 0; i < XDP_ACTION_MAX; i++)
map_collect_percpu(&sample_mmap[MAP_EXCEPTION][i * sample_n_cpus],
Expand All @@ -906,6 +1122,7 @@ 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.err += out->totals.err;
sample_out.rx_cnt.pps += interval;
}
Expand Down
6 changes: 6 additions & 0 deletions samples/bpf/xdp_sample_user.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,8 @@ enum stats_mask {
_SAMPLE_REDIRECT_MAP = 1U << 0,
SAMPLE_RX_CNT = 1U << 1,
SAMPLE_REDIRECT_ERR_CNT = 1U << 2,
SAMPLE_CPUMAP_ENQUEUE_CNT = 1U << 3,
SAMPLE_CPUMAP_KTHREAD_CNT = 1U << 4,
SAMPLE_EXCEPTION_CNT = 1U << 5,
SAMPLE_REDIRECT_CNT = 1U << 7,
SAMPLE_REDIRECT_MAP_CNT = SAMPLE_REDIRECT_CNT | _SAMPLE_REDIRECT_MAP,
Expand Down Expand Up @@ -76,6 +78,10 @@ static inline char *safe_strncpy(char *dst, const char *src, size_t size)
__attach_tp(tp_xdp_redirect_map_err); \
if (mask & SAMPLE_REDIRECT_ERR_CNT) \
__attach_tp(tp_xdp_redirect_err); \
if (mask & SAMPLE_CPUMAP_ENQUEUE_CNT) \
__attach_tp(tp_xdp_cpumap_enqueue); \
if (mask & SAMPLE_CPUMAP_KTHREAD_CNT) \
__attach_tp(tp_xdp_cpumap_kthread); \
if (mask & SAMPLE_EXCEPTION_CNT) \
__attach_tp(tp_xdp_exception); \
return 0; \
Expand Down

0 comments on commit d771e21

Please sign in to comment.