Re: [PATCH 2/2] tools/rtla: fix collision with glibc sched_attr/sched_set_attr

[Tomas Glozar]

čt 10. 10. 2024 v 11:33 odesílatel Jan Stancek <jstancek@xxxxxxxxxx> napsal:
>
> glibc commit 21571ca0d703 ("Linux: Add the sched_setattr
> and sched_getattr functions") now also provides 'struct sched_attr'
> and sched_setattr() which collide with the ones from rtla.
>
>   In file included from src/trace.c:11:
>   src/utils.h:49:8: error: redefinition of ‘struct sched_attr’
>      49 | struct sched_attr {
>         |        ^~~~~~~~~~
>   In file included from /usr/include/bits/sched.h:60,
>                    from /usr/include/sched.h:43,
>                    from /usr/include/tracefs/tracefs.h:10,
>                    from src/trace.c:4:
>   /usr/include/linux/sched/types.h:98:8: note: originally defined here
>      98 | struct sched_attr {
>         |        ^~~~~~~~~~
>
> Define 'struct sched_attr' conditionally, similar to what strace did:
>   https://lore.kernel.org/all/20240930222913.3981407-1-raj.khem@xxxxxxxxx/
> and rename rtla's version of sched_setattr() to avoid collision.
>
> Signed-off-by: Jan Stancek <jstancek@xxxxxxxxxx>
> ---
>  tools/tracing/rtla/src/utils.c | 4 ++--
>  tools/tracing/rtla/src/utils.h | 2 ++
>  2 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/tools/tracing/rtla/src/utils.c b/tools/tracing/rtla/src/utils.c
> index 05b2b3fc005e..c62044215a48 100644
> --- a/tools/tracing/rtla/src/utils.c
> +++ b/tools/tracing/rtla/src/utils.c
> @@ -229,7 +229,7 @@ long parse_ns_duration(char *val)
>
>  #define SCHED_DEADLINE         6
>
> -static inline int sched_setattr(pid_t pid, const struct sched_attr *attr,
> +static inline int rtla_sched_setattr(pid_t pid, const struct sched_attr *attr,

Hmm, rtla_sched_attr sounds to me like the function does something
specific to rtla. Maybe syscall_sched_attr would be a better name?

>                                 unsigned int flags) {
>         return syscall(__NR_sched_setattr, pid, attr, flags);
>  }
> @@ -239,7 +239,7 @@ int __set_sched_attr(int pid, struct sched_attr *attr)
>         int flags = 0;
>         int retval;
>
> -       retval = sched_setattr(pid, attr, flags);
> +       retval = rtla_sched_setattr(pid, attr, flags);
>         if (retval < 0) {
>                 err_msg("Failed to set sched attributes to the pid %d: %s\n",
>                         pid, strerror(errno));
> diff --git a/tools/tracing/rtla/src/utils.h b/tools/tracing/rtla/src/utils.h
> index d44513e6c66a..99c9cf81bcd0 100644
> --- a/tools/tracing/rtla/src/utils.h
> +++ b/tools/tracing/rtla/src/utils.h
> @@ -46,6 +46,7 @@ update_sum(unsigned long long *a, unsigned long long *b)
>         *a += *b;
>  }
>
> +#ifndef SCHED_ATTR_SIZE_VER0
>  struct sched_attr {
>         uint32_t size;
>         uint32_t sched_policy;
> @@ -56,6 +57,7 @@ struct sched_attr {
>         uint64_t sched_deadline;
>         uint64_t sched_period;
>  };
> +#endif /* SCHED_ATTR_SIZE_VER0 */
>
>  int parse_prio(char *arg, struct sched_attr *sched_param);
>  int parse_cpu_set(char *cpu_list, cpu_set_t *set);
> --
> 2.43.0
>

Apart from that, LGTM.


Tomas