On Wed, 22 Apr 2020, Yunfeng Ye wrote:
> An Error occurs when run: ./cyclictest -v -t 5 -p 80 -i 1000 -a 3
>
> parse_cpumask: Using 0 cpus.
> Max CPUs = 96
> WARN: Couldn't setaffinity in main thread: Invalid argument
> # /dev/cpu_dma_latency set to 0us
> FATAL: No allowable cpus to run on
>
> We find that numa_bitmask_alloc() is used incorrectly in
> use_current_cpuset(), it should pass the number of cpus as parameters,
> not the sizeof(struct bitmask), which is only 8 bytes.
>
> The syscall sched_getaffinity will check the parameters, if using
> sizeof(struct bitmask), it will fail when cpus is more:
>
> SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len,
> unsigned long __user *, user_mask_ptr)
> {
> int ret;
> cpumask_var_t mask;
>
> if ((len * BITS_PER_BYTE) < nr_cpu_ids)
> return -EINVAL;
>
> Fix it by passing max_cpus as parameters to numa_bitmask_alloc().
>
> Signed-off-by: Yunfeng Ye <yeyunfeng@xxxxxxxxxx>
> ---
> src/cyclictest/cyclictest.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest.c
> index c5f1fd46567a..989113fb3483 100644
> --- a/src/cyclictest/cyclictest.c
> +++ b/src/cyclictest/cyclictest.c
> @@ -1135,7 +1135,7 @@ static void use_current_cpuset(const int max_cpus)
>
> pid = getpid();
>
> - curmask = numa_bitmask_alloc(sizeof(struct bitmask));
> + curmask = numa_bitmask_alloc(max_cpus);
> numa_sched_getaffinity(pid, curmask);
>
> /* Clear bits that are not set in both the cpuset from the environment,
> --
> 1.8.3.1
>
>
>
Signed-off-by: John Kacur <jkacur@xxxxxxxxxx>
Thanks!
