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| author | Sandipan Das <sandipan@linux.ibm.com> | 2020-07-30 08:08:46 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-08-19 09:26:49 +0300 |
| commit | fd926b32b9ca79625ca3fa5f74937a95230b77a2 (patch) | |
| tree | 662b01dbff8654a631e6a8fbdc23fbb81ea6f134 /tools/testing | |
| parent | 3e444bad470ead7f965d34f351e3b44ff214b6b4 (diff) | |
| download | linux-fd926b32b9ca79625ca3fa5f74937a95230b77a2.tar.xz | |
selftests/powerpc: Fix online CPU selection
[ Upstream commit dfa03fff86027e58c8dba5c03ae68150d4e513ad ]
The size of the CPU affinity mask must be large enough for
systems with a very large number of CPUs. Otherwise, tests
which try to determine the first online CPU by calling
sched_getaffinity() will fail. This makes sure that the size
of the allocated affinity mask is dependent on the number of
CPUs as reported by get_nprocs_conf().
Fixes: 3752e453f6ba ("selftests/powerpc: Add tests of PMU EBBs")
Reported-by: Shirisha Ganta <shiganta@in.ibm.com>
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a408c4b8e9a23bb39b539417a21eb0ff47bb5127.1596084858.git.sandipan@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'tools/testing')
| -rw-r--r-- | tools/testing/selftests/powerpc/utils.c | 37 |
1 files changed, 25 insertions, 12 deletions
diff --git a/tools/testing/selftests/powerpc/utils.c b/tools/testing/selftests/powerpc/utils.c index 5ee0e98c4896..eb530e73e02c 100644 --- a/tools/testing/selftests/powerpc/utils.c +++ b/tools/testing/selftests/powerpc/utils.c @@ -16,6 +16,7 @@ #include <string.h> #include <sys/ioctl.h> #include <sys/stat.h> +#include <sys/sysinfo.h> #include <sys/types.h> #include <sys/utsname.h> #include <unistd.h> @@ -88,28 +89,40 @@ void *get_auxv_entry(int type) int pick_online_cpu(void) { - cpu_set_t mask; - int cpu; + int ncpus, cpu = -1; + cpu_set_t *mask; + size_t size; + + ncpus = get_nprocs_conf(); + size = CPU_ALLOC_SIZE(ncpus); + mask = CPU_ALLOC(ncpus); + if (!mask) { + perror("malloc"); + return -1; + } - CPU_ZERO(&mask); + CPU_ZERO_S(size, mask); - if (sched_getaffinity(0, sizeof(mask), &mask)) { + if (sched_getaffinity(0, size, mask)) { perror("sched_getaffinity"); - return -1; + goto done; } /* We prefer a primary thread, but skip 0 */ - for (cpu = 8; cpu < CPU_SETSIZE; cpu += 8) - if (CPU_ISSET(cpu, &mask)) - return cpu; + for (cpu = 8; cpu < ncpus; cpu += 8) + if (CPU_ISSET_S(cpu, size, mask)) + goto done; /* Search for anything, but in reverse */ - for (cpu = CPU_SETSIZE - 1; cpu >= 0; cpu--) - if (CPU_ISSET(cpu, &mask)) - return cpu; + for (cpu = ncpus - 1; cpu >= 0; cpu--) + if (CPU_ISSET_S(cpu, size, mask)) + goto done; printf("No cpus in affinity mask?!\n"); - return -1; + +done: + CPU_FREE(mask); + return cpu; } bool is_ppc64le(void) |