Commit 67ed3755 authored by Ciara Loftus's avatar Ciara Loftus Committed by Alexei Starovoitov

samples: bpf: Driver interrupt statistics in xdpsock

Add an option to count the number of interrupts generated per second and
total number of interrupts during the lifetime of the application for a
given interface. This information is extracted from /proc/interrupts. Since
there is no naming convention across drivers, the user must provide the
string which is specific to their interface in the /proc/interrupts file on
the command line.

Usage:

./xdpsock ... -I <irq_str>

eg. for queue 0 of i40e device eth0:

./xdpsock ... -I i40e-eth0-TxRx-0
Signed-off-by: default avatarCiara Loftus <ciara.loftus@intel.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201002133612.31536-3-ciara.loftus@intel.com
parent 60dc609d
......@@ -11,6 +11,7 @@
#include <linux/if_xdp.h>
#include <linux/if_ether.h>
#include <linux/ip.h>
#include <linux/limits.h>
#include <linux/udp.h>
#include <arpa/inet.h>
#include <locale.h>
......@@ -80,6 +81,9 @@ static u32 opt_pkt_fill_pattern = 0x12345678;
static bool opt_extra_stats;
static bool opt_quiet;
static bool opt_app_stats;
static const char *opt_irq_str = "";
static u32 irq_no;
static int irqs_at_init = -1;
static int opt_poll;
static int opt_interval = 1;
static u32 opt_xdp_bind_flags = XDP_USE_NEED_WAKEUP;
......@@ -111,6 +115,11 @@ struct xsk_ring_stats {
unsigned long prev_tx_empty_npkts;
};
struct xsk_driver_stats {
unsigned long intrs;
unsigned long prev_intrs;
};
struct xsk_app_stats {
unsigned long rx_empty_polls;
unsigned long fill_fail_polls;
......@@ -138,6 +147,7 @@ struct xsk_socket_info {
struct xsk_socket *xsk;
struct xsk_ring_stats ring_stats;
struct xsk_app_stats app_stats;
struct xsk_driver_stats drv_stats;
u32 outstanding_tx;
};
......@@ -243,6 +253,100 @@ static void dump_app_stats(long dt)
}
}
static bool get_interrupt_number(void)
{
FILE *f_int_proc;
char line[4096];
bool found = false;
f_int_proc = fopen("/proc/interrupts", "r");
if (f_int_proc == NULL) {
printf("Failed to open /proc/interrupts.\n");
return found;
}
while (!feof(f_int_proc) && !found) {
/* Make sure to read a full line at a time */
if (fgets(line, sizeof(line), f_int_proc) == NULL ||
line[strlen(line) - 1] != '\n') {
printf("Error reading from interrupts file\n");
break;
}
/* Extract interrupt number from line */
if (strstr(line, opt_irq_str) != NULL) {
irq_no = atoi(line);
found = true;
break;
}
}
fclose(f_int_proc);
return found;
}
static int get_irqs(void)
{
char count_path[PATH_MAX];
int total_intrs = -1;
FILE *f_count_proc;
char line[4096];
snprintf(count_path, sizeof(count_path),
"/sys/kernel/irq/%i/per_cpu_count", irq_no);
f_count_proc = fopen(count_path, "r");
if (f_count_proc == NULL) {
printf("Failed to open %s\n", count_path);
return total_intrs;
}
if (fgets(line, sizeof(line), f_count_proc) == NULL ||
line[strlen(line) - 1] != '\n') {
printf("Error reading from %s\n", count_path);
} else {
static const char com[2] = ",";
char *token;
total_intrs = 0;
token = strtok(line, com);
while (token != NULL) {
/* sum up interrupts across all cores */
total_intrs += atoi(token);
token = strtok(NULL, com);
}
}
fclose(f_count_proc);
return total_intrs;
}
static void dump_driver_stats(long dt)
{
int i;
for (i = 0; i < num_socks && xsks[i]; i++) {
char *fmt = "%-18s %'-14.0f %'-14lu\n";
double intrs_ps;
int n_ints = get_irqs();
if (n_ints < 0) {
printf("error getting intr info for intr %i\n", irq_no);
return;
}
xsks[i]->drv_stats.intrs = n_ints - irqs_at_init;
intrs_ps = (xsks[i]->drv_stats.intrs - xsks[i]->drv_stats.prev_intrs) *
1000000000. / dt;
printf("\n%-18s %-14s %-14s\n", "", "intrs/s", "count");
printf(fmt, "irqs", intrs_ps, xsks[i]->drv_stats.intrs);
xsks[i]->drv_stats.prev_intrs = xsks[i]->drv_stats.intrs;
}
}
static void dump_stats(void)
{
unsigned long now = get_nsecs();
......@@ -327,6 +431,8 @@ static void dump_stats(void)
if (opt_app_stats)
dump_app_stats(dt);
if (irq_no)
dump_driver_stats(dt);
}
static bool is_benchmark_done(void)
......@@ -804,6 +910,7 @@ static struct option long_options[] = {
{"extra-stats", no_argument, 0, 'x'},
{"quiet", no_argument, 0, 'Q'},
{"app-stats", no_argument, 0, 'a'},
{"irq-string", no_argument, 0, 'I'},
{0, 0, 0, 0}
};
......@@ -841,6 +948,7 @@ static void usage(const char *prog)
" -x, --extra-stats Display extra statistics.\n"
" -Q, --quiet Do not display any stats.\n"
" -a, --app-stats Display application (syscall) statistics.\n"
" -I, --irq-string Display driver interrupt statistics for interface associated with irq-string.\n"
"\n";
fprintf(stderr, str, prog, XSK_UMEM__DEFAULT_FRAME_SIZE,
opt_batch_size, MIN_PKT_SIZE, MIN_PKT_SIZE,
......@@ -856,7 +964,7 @@ static void parse_command_line(int argc, char **argv)
opterr = 0;
for (;;) {
c = getopt_long(argc, argv, "Frtli:q:pSNn:czf:muMd:b:C:s:P:xQa",
c = getopt_long(argc, argv, "Frtli:q:pSNn:czf:muMd:b:C:s:P:xQaI:",
long_options, &option_index);
if (c == -1)
break;
......@@ -945,6 +1053,16 @@ static void parse_command_line(int argc, char **argv)
break;
case 'a':
opt_app_stats = 1;
break;
case 'I':
opt_irq_str = optarg;
if (get_interrupt_number())
irqs_at_init = get_irqs();
if (irqs_at_init < 0) {
fprintf(stderr, "ERROR: Failed to get irqs for %s\n", opt_irq_str);
usage(basename(argv[0]));
}
break;
default:
usage(basename(argv[0]));
......
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