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![Matteo Croce](/assets/img/avatar_default.png)
GCC 10 is very strict about symbol clash, and lwt_len_hist_user contains a symbol which clashes with libbpf: /usr/bin/ld: samples/bpf/lwt_len_hist_user.o:(.bss+0x0): multiple definition of `bpf_log_buf'; samples/bpf/bpf_load.o:(.bss+0x8c0): first defined here collect2: error: ld returned 1 exit status bpf_log_buf here seems to be a leftover, so removing it. Signed-off-by: Matteo Croce <mcroce@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200511113234.80722-1-mcroce@redhat.com
77 lines
1.6 KiB
C
77 lines
1.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/unistd.h>
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#include <linux/bpf.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <unistd.h>
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#include <string.h>
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#include <errno.h>
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#include <arpa/inet.h>
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#include <bpf/bpf.h>
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#include "bpf_util.h"
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#define MAX_INDEX 64
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#define MAX_STARS 38
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static void stars(char *str, long val, long max, int width)
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{
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int i;
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for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++)
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str[i] = '*';
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if (val > max)
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str[i - 1] = '+';
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str[i] = '\0';
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}
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int main(int argc, char **argv)
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{
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unsigned int nr_cpus = bpf_num_possible_cpus();
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const char *map_filename = "/sys/fs/bpf/tc/globals/lwt_len_hist_map";
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uint64_t values[nr_cpus], sum, max_value = 0, data[MAX_INDEX] = {};
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uint64_t key = 0, next_key, max_key = 0;
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char starstr[MAX_STARS];
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int i, map_fd;
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map_fd = bpf_obj_get(map_filename);
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if (map_fd < 0) {
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fprintf(stderr, "bpf_obj_get(%s): %s(%d)\n",
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map_filename, strerror(errno), errno);
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return -1;
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}
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while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0) {
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if (next_key >= MAX_INDEX) {
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fprintf(stderr, "Key %lu out of bounds\n", next_key);
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continue;
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}
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bpf_map_lookup_elem(map_fd, &next_key, values);
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sum = 0;
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for (i = 0; i < nr_cpus; i++)
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sum += values[i];
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data[next_key] = sum;
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if (sum && next_key > max_key)
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max_key = next_key;
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if (sum > max_value)
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max_value = sum;
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key = next_key;
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}
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for (i = 1; i <= max_key + 1; i++) {
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stars(starstr, data[i - 1], max_value, MAX_STARS);
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printf("%8ld -> %-8ld : %-8ld |%-*s|\n",
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(1l << i) >> 1, (1l << i) - 1, data[i - 1],
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MAX_STARS, starstr);
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}
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close(map_fd);
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return 0;
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}
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