Commit 4c587c19 authored by Hechao Li's avatar Hechao Li Committed by Daniel Borkmann
Browse files

bpf: use libbpf_num_possible_cpus internally 



Use the newly added bpf_num_possible_cpus() in bpftool and selftests
and remove duplicate implementations.

Signed-off-by: default avatarHechao Li <hechaol@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent ebb88607

tools/bpf/bpftool/common.c

+5 −48
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#include <sys/vfs.h>



#include <bpf.h>

#include <libbpf.h> /* libbpf_num_possible_cpus */



#include "main.h"
@@ -439,57 +440,13 @@ unsigned int get_page_size(void) 


unsigned int get_possible_cpus(void)

{

	static unsigned int result;

	char buf[128];

	long int n;

	char *ptr;

	int fd;



	if (result)

		return result;



	fd = open("/sys/devices/system/cpu/possible", O_RDONLY);

	if (fd < 0) {

		p_err("can't open sysfs possible cpus");

		exit(-1);

	}



	n = read(fd, buf, sizeof(buf));

	if (n < 2) {

		p_err("can't read sysfs possible cpus");

		exit(-1);

	}

	close(fd);

	int cpus = libbpf_num_possible_cpus();



	if (n == sizeof(buf)) {

		p_err("read sysfs possible cpus overflow");

	if (cpus < 0) {

		p_err("Can't get # of possible cpus: %s", strerror(-cpus));

		exit(-1);

	}



	ptr = buf;

	n = 0;

	while (*ptr && *ptr != '\n') {

		unsigned int a, b;



		if (sscanf(ptr, "%u-%u", &a, &b) == 2) {

			n += b - a + 1;



			ptr = strchr(ptr, '-') + 1;

		} else if (sscanf(ptr, "%u", &a) == 1) {

			n++;

		} else {

			assert(0);

		}



		while (isdigit(*ptr))

			ptr++;

		if (*ptr == ',')

			ptr++;

	}



	result = n;



	return result;

	return cpus;

}



static char *

tools/testing/selftests/bpf/bpf_util.h

+5 −32
Original line number Diff line number Diff line
@@ -6,44 +6,17 @@ 
#include <stdlib.h>

#include <string.h>

#include <errno.h>

#include <libbpf.h> /* libbpf_num_possible_cpus */



static inline unsigned int bpf_num_possible_cpus(void)

{

	static const char *fcpu = "/sys/devices/system/cpu/possible";

	unsigned int start, end, possible_cpus = 0;

	char buff[128];

	FILE *fp;

	int len, n, i, j = 0;

	int possible_cpus = libbpf_num_possible_cpus();



	fp = fopen(fcpu, "r");

	if (!fp) {

		printf("Failed to open %s: '%s'!\n", fcpu, strerror(errno));

	if (possible_cpus < 0) {

		printf("Failed to get # of possible cpus: '%s'!\n",

		       strerror(-possible_cpus));

		exit(1);

	}



	if (!fgets(buff, sizeof(buff), fp)) {

		printf("Failed to read %s!\n", fcpu);

		exit(1);

	}



	len = strlen(buff);

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

		if (buff[i] == ',' || buff[i] == '\0') {

			buff[i] = '\0';

			n = sscanf(&buff[j], "%u-%u", &start, &end);

			if (n <= 0) {

				printf("Failed to retrieve # possible CPUs!\n");

				exit(1);

			} else if (n == 1) {

				end = start;

			}

			possible_cpus += end - start + 1;

			j = i + 1;

		}

	}



	fclose(fp);



	return possible_cpus;

}