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author | Martynas Pumputis <m@lambda.lt> | 2019-01-31 12:19:33 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-03-14 00:03:20 +0300 |
commit | 3084058a72e297e7dbce277b8161fc323d087d1d (patch) | |
tree | 4ead9b5e476404cd1c941c4a5859a09159c24572 /tools/testing | |
parent | 167a0989ec15a0b738dc8fd25922b1fae00c0dba (diff) | |
download | linux-3084058a72e297e7dbce277b8161fc323d087d1d.tar.xz |
bpf, selftests: fix handling of sparse CPU allocations
[ Upstream commit 1bb54c4071f585ebef56ce8fdfe6026fa2cbcddd ]
Previously, bpf_num_possible_cpus() had a bug when calculating a
number of possible CPUs in the case of sparse CPU allocations, as
it was considering only the first range or element of
/sys/devices/system/cpu/possible.
E.g. in the case of "0,2-3" (CPU 1 is not available), the function
returned 1 instead of 3.
This patch fixes the function by making it parse all CPU ranges and
elements.
Signed-off-by: Martynas Pumputis <m@lambda.lt>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'tools/testing')
-rw-r--r-- | tools/testing/selftests/bpf/bpf_util.h | 30 |
1 files changed, 20 insertions, 10 deletions
diff --git a/tools/testing/selftests/bpf/bpf_util.h b/tools/testing/selftests/bpf/bpf_util.h index d0811b3d6a6f..4bf720364934 100644 --- a/tools/testing/selftests/bpf/bpf_util.h +++ b/tools/testing/selftests/bpf/bpf_util.h @@ -13,7 +13,7 @@ static inline unsigned int bpf_num_possible_cpus(void) unsigned int start, end, possible_cpus = 0; char buff[128]; FILE *fp; - int n; + int len, n, i, j = 0; fp = fopen(fcpu, "r"); if (!fp) { @@ -21,17 +21,27 @@ static inline unsigned int bpf_num_possible_cpus(void) exit(1); } - while (fgets(buff, sizeof(buff), fp)) { - n = sscanf(buff, "%u-%u", &start, &end); - if (n == 0) { - printf("Failed to retrieve # possible CPUs!\n"); - exit(1); - } else if (n == 1) { - end = start; + 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; } - possible_cpus = start == 0 ? end + 1 : 0; - break; } + fclose(fp); return possible_cpus; |