From: Ong Boon Leong <boon.leong.ong@intel.com>
Date: Thu, 30 Dec 2021 11:54:45 +0800
Subject: samples/bpf: xdpsock: Add sched policy and priority support
Patch-mainline: v5.17-rc1
Git-commit: fa24d0b1d57825d1a5b802339728d4d8ac20b6d6
References: jsc#PED-1368
By default, TX schedule policy is SCHED_OTHER (round-robin time-sharing).
To improve TX cyclic scheduling, we add SCHED_FIFO policy and its priority
by using -W FIFO or --policy=FIFO and -U <PRIO> or --schpri=<PRIO>.
A) From xdpsock --app-stats, for SCHED_OTHER policy:
$ xdpsock -i eth0 -t -N -z -T 1000 -b 16 -C 100000 -a
period min ave max cycle
Cyclic TX 1000000 53507 75334 712642 6250
B) For SCHED_FIFO policy and schpri=50:
$ xdpsock -i eth0 -t -N -z -T 1000 -b 16 -C 100000 -a -W FIFO -U 50
period min ave max cycle
Cyclic TX 1000000 3699 24859 54397 6250
Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211230035447.523177-6-boon.leong.ong@intel.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
samples/bpf/xdpsock_user.c | 61 +++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 59 insertions(+), 2 deletions(-)
--- a/samples/bpf/xdpsock_user.c
+++ b/samples/bpf/xdpsock_user.c
@@ -31,6 +31,7 @@
#include <sys/un.h>
#include <time.h>
#include <unistd.h>
+#include <sched.h>
#include <bpf/libbpf.h>
#include <bpf/xsk.h>
@@ -66,6 +67,8 @@
#define NSEC_PER_SEC 1000000000UL
#define NSEC_PER_USEC 1000
+#define SCHED_PRI__DEFAULT 0
+
typedef __u64 u64;
typedef __u32 u32;
typedef __u16 u16;
@@ -123,6 +126,8 @@ static bool opt_busy_poll;
static bool opt_reduced_cap;
static clockid_t opt_clock = CLOCK_MONOTONIC;
static unsigned long opt_tx_cycle_ns;
+static int opt_schpolicy = SCHED_OTHER;
+static int opt_schprio = SCHED_PRI__DEFAULT;
struct vlan_ethhdr {
unsigned char h_dest[6];
@@ -198,6 +203,15 @@ static const struct clockid_map {
{ NULL }
};
+static const struct sched_map {
+ const char *name;
+ int policy;
+} schmap[] = {
+ { "OTHER", SCHED_OTHER },
+ { "FIFO", SCHED_FIFO },
+ { NULL }
+};
+
static int num_socks;
struct xsk_socket_info *xsks[MAX_SOCKS];
int sock;
@@ -216,6 +230,20 @@ static int get_clockid(clockid_t *id, co
return -1;
}
+static int get_schpolicy(int *policy, const char *name)
+{
+ const struct sched_map *sch;
+
+ for (sch = schmap; sch->name; sch++) {
+ if (strcasecmp(sch->name, name) == 0) {
+ *policy = sch->policy;
+ return 0;
+ }
+ }
+
+ return -1;
+}
+
static unsigned long get_nsecs(void)
{
struct timespec ts;
@@ -1019,6 +1047,8 @@ static struct option long_options[] = {
{"tx-dmac", required_argument, 0, 'G'},
{"tx-smac", required_argument, 0, 'H'},
{"tx-cycle", required_argument, 0, 'T'},
+ {"policy", required_argument, 0, 'W'},
+ {"schpri", required_argument, 0, 'U'},
{"extra-stats", no_argument, 0, 'x'},
{"quiet", no_argument, 0, 'Q'},
{"app-stats", no_argument, 0, 'a'},
@@ -1066,6 +1096,8 @@ static void usage(const char *prog)
" -G, --tx-dmac=<MAC> Dest MAC addr of TX frame in aa:bb:cc:dd:ee:ff format (For -V|--tx-vlan)\n"
" -H, --tx-smac=<MAC> Src MAC addr of TX frame in aa:bb:cc:dd:ee:ff format (For -V|--tx-vlan)\n"
" -T, --tx-cycle=n Tx cycle time in micro-seconds (For -t|--txonly).\n"
+ " -W, --policy=POLICY Schedule policy. Default: SCHED_OTHER\n"
+ " -U, --schpri=n Schedule priority. Default: %d\n"
" -x, --extra-stats Display extra statistics.\n"
" -Q, --quiet Do not display any stats.\n"
" -a, --app-stats Display application (syscall) statistics.\n"
@@ -1076,7 +1108,8 @@ static void usage(const char *prog)
fprintf(stderr, str, prog, XSK_UMEM__DEFAULT_FRAME_SIZE,
opt_batch_size, MIN_PKT_SIZE, MIN_PKT_SIZE,
XSK_UMEM__DEFAULT_FRAME_SIZE, opt_pkt_fill_pattern,
- VLAN_VID__DEFAULT, VLAN_PRI__DEFAULT);
+ VLAN_VID__DEFAULT, VLAN_PRI__DEFAULT,
+ SCHED_PRI__DEFAULT);
exit(EXIT_FAILURE);
}
@@ -1088,7 +1121,8 @@ static void parse_command_line(int argc,
opterr = 0;
for (;;) {
- c = getopt_long(argc, argv, "Frtli:q:pSNn:w:czf:muMd:b:C:s:P:VJ:K:G:H:T:xQaI:BR",
+ c = getopt_long(argc, argv,
+ "Frtli:q:pSNn:w:czf:muMd:b:C:s:P:VJ:K:G:H:T:W:U:xQaI:BR",
long_options, &option_index);
if (c == -1)
break;
@@ -1206,6 +1240,17 @@ static void parse_command_line(int argc,
opt_tx_cycle_ns = atoi(optarg);
opt_tx_cycle_ns *= NSEC_PER_USEC;
break;
+ case 'W':
+ if (get_schpolicy(&opt_schpolicy, optarg)) {
+ fprintf(stderr,
+ "ERROR: Invalid policy %s. Default to SCHED_OTHER.\n",
+ optarg);
+ opt_schpolicy = SCHED_OTHER;
+ }
+ break;
+ case 'U':
+ opt_schprio = atoi(optarg);
+ break;
case 'x':
opt_extra_stats = 1;
break;
@@ -1780,6 +1825,7 @@ int main(int argc, char **argv)
struct __user_cap_data_struct data[2] = { { 0 } };
struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
bool rx = false, tx = false;
+ struct sched_param schparam;
struct xsk_umem_info *umem;
struct bpf_object *obj;
int xsks_map_fd = 0;
@@ -1881,6 +1927,16 @@ int main(int argc, char **argv)
prev_time = get_nsecs();
start_time = prev_time;
+ /* Configure sched priority for better wake-up accuracy */
+ memset(&schparam, 0, sizeof(schparam));
+ schparam.sched_priority = opt_schprio;
+ ret = sched_setscheduler(0, opt_schpolicy, &schparam);
+ if (ret) {
+ fprintf(stderr, "Error(%d) in setting priority(%d): %s\n",
+ errno, opt_schprio, strerror(errno));
+ goto out;
+ }
+
if (opt_bench == BENCH_RXDROP)
rx_drop_all();
else if (opt_bench == BENCH_TXONLY)
@@ -1888,6 +1944,7 @@ int main(int argc, char **argv)
else
l2fwd_all();
+out:
benchmark_done = true;
if (!opt_quiet)