Commit 6a098154 authored by Lorenzo Bianconi's avatar Lorenzo Bianconi Committed by Alexei Starovoitov
Browse files

samples/bpf: xdp_redirect_cpu: Set MAX_CPUS according to NR_CPUS 



xdp_redirect_cpu is currently failing in bpf_prog_load_xattr()
allocating cpu_map map if CONFIG_NR_CPUS is less than 64 since
cpu_map_alloc() requires max_entries to be less than NR_CPUS.
Set cpu_map max_entries according to NR_CPUS in xdp_redirect_cpu_kern.c
and get currently running cpus in xdp_redirect_cpu_user.c

Signed-off-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/374472755001c260158c4e4b22f193bdd3c56fb7.1589300442.git.lorenzo@kernel.org
parent 8f4605ac

samples/bpf/xdp_redirect_cpu_kern.c

+1 −1
Original line number Diff line number Diff line
@@ -15,7 +15,7 @@ 
#include <bpf/bpf_helpers.h>

#include "hash_func01.h"



#define MAX_CPUS 64 /* WARNING - sync with _user.c */

#define MAX_CPUS NR_CPUS



/* Special map type that can XDP_REDIRECT frames to another CPU */

struct {

samples/bpf/xdp_redirect_cpu_user.c

+16 −13
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ static const char *__doc__ = 
#include <unistd.h>

#include <locale.h>

#include <sys/resource.h>

#include <sys/sysinfo.h>

#include <getopt.h>

#include <net/if.h>

#include <time.h>
@@ -24,8 +25,6 @@ static const char *__doc__ = 
#include <arpa/inet.h>

#include <linux/if_link.h>



#define MAX_CPUS 64 /* WARNING - sync with _kern.c */



/* How many xdp_progs are defined in _kern.c */

#define MAX_PROG 6
@@ -40,6 +39,7 @@ static char *ifname; 
static __u32 prog_id;



static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;

static int n_cpus;

static int cpu_map_fd;

static int rx_cnt_map_fd;

static int redirect_err_cnt_map_fd;
@@ -170,7 +170,7 @@ struct stats_record { 
	struct record redir_err;

	struct record kthread;

	struct record exception;

	struct record enq[MAX_CPUS];

	struct record enq[];

};



static bool map_collect_percpu(int fd, __u32 key, struct record *rec)
@@ -225,10 +225,11 @@ static struct datarec *alloc_record_per_cpu(void) 
static struct stats_record *alloc_stats_record(void)

{

	struct stats_record *rec;

	int i;

	int i, size;



	rec = malloc(sizeof(*rec));

	memset(rec, 0, sizeof(*rec));

	size = sizeof(*rec) + n_cpus * sizeof(struct record);

	rec = malloc(size);

	memset(rec, 0, size);

	if (!rec) {

		fprintf(stderr, "Mem alloc error\n");

		exit(EXIT_FAIL_MEM);
@@ -237,7 +238,7 @@ static struct stats_record *alloc_stats_record(void) 
	rec->redir_err.cpu = alloc_record_per_cpu();

	rec->kthread.cpu   = alloc_record_per_cpu();

	rec->exception.cpu = alloc_record_per_cpu();

	for (i = 0; i < MAX_CPUS; i++)

	for (i = 0; i < n_cpus; i++)

		rec->enq[i].cpu = alloc_record_per_cpu();



	return rec;
@@ -247,7 +248,7 @@ static void free_stats_record(struct stats_record *r) 
{

	int i;



	for (i = 0; i < MAX_CPUS; i++)

	for (i = 0; i < n_cpus; i++)

		free(r->enq[i].cpu);

	free(r->exception.cpu);

	free(r->kthread.cpu);
@@ -350,7 +351,7 @@ static void stats_print(struct stats_record *stats_rec, 
	}



	/* cpumap enqueue stats */

	for (to_cpu = 0; to_cpu < MAX_CPUS; to_cpu++) {

	for (to_cpu = 0; to_cpu < n_cpus; to_cpu++) {

		char *fmt = "%-15s %3d:%-3d %'-14.0f %'-11.0f %'-10.2f %s\n";

		char *fm2 = "%-15s %3s:%-3d %'-14.0f %'-11.0f %'-10.2f %s\n";

		char *errstr = "";
@@ -475,7 +476,7 @@ static void stats_collect(struct stats_record *rec) 
	map_collect_percpu(fd, 1, &rec->redir_err);



	fd = cpumap_enqueue_cnt_map_fd;

	for (i = 0; i < MAX_CPUS; i++)

	for (i = 0; i < n_cpus; i++)

		map_collect_percpu(fd, i, &rec->enq[i]);



	fd = cpumap_kthread_cnt_map_fd;
@@ -549,10 +550,10 @@ static int create_cpu_entry(__u32 cpu, __u32 queue_size, 
 */

static void mark_cpus_unavailable(void)

{

	__u32 invalid_cpu = MAX_CPUS;

	__u32 invalid_cpu = n_cpus;

	int ret, i;



	for (i = 0; i < MAX_CPUS; i++) {

	for (i = 0; i < n_cpus; i++) {

		ret = bpf_map_update_elem(cpus_available_map_fd, &i,

					  &invalid_cpu, 0);

		if (ret) {
@@ -688,6 +689,8 @@ int main(int argc, char **argv) 
	int prog_fd;

	__u32 qsize;



	n_cpus = get_nprocs_conf();



	/* Notice: choosing he queue size is very important with the

	 * ixgbe driver, because it's driver page recycling trick is

	 * dependend on pages being returned quickly.  The number of
@@ -757,7 +760,7 @@ int main(int argc, char **argv) 
		case 'c':

			/* Add multiple CPUs */

			add_cpu = strtoul(optarg, NULL, 0);

			if (add_cpu >= MAX_CPUS) {

			if (add_cpu >= n_cpus) {

				fprintf(stderr,

				"--cpu nr too large for cpumap err(%d):%s\n",

					errno, strerror(errno));

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