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author | Ciara Loftus <ciara.loftus@intel.com> | 2020-10-02 13:36:12 +0000 |
---|---|---|
committer | Alexei Starovoitov <ast@kernel.org> | 2020-10-06 11:46:50 -0700 |
commit | 67ed375530e223624508382a9348a21c3b2ccc09 (patch) | |
tree | 1afad1359b572a061f5c0ad49969fcc2e6b7fb17 /samples | |
parent | 60dc609dbd545226e00c9e7b518d0f4873f0a3e1 (diff) | |
download | lwn-67ed375530e223624508382a9348a21c3b2ccc09.tar.gz lwn-67ed375530e223624508382a9348a21c3b2ccc09.zip |
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: Ciara Loftus <ciara.loftus@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201002133612.31536-3-ciara.loftus@intel.com
Diffstat (limited to 'samples')
-rw-r--r-- | samples/bpf/xdpsock_user.c | 120 |
1 files changed, 119 insertions, 1 deletions
diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c index ff119ede4ab1..1149e94ca32f 100644 --- a/samples/bpf/xdpsock_user.c +++ b/samples/bpf/xdpsock_user.c @@ -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; @@ -946,6 +1054,16 @@ static void parse_command_line(int argc, char **argv) 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])); } |