[PATCH v3] eal: update lcore-worker name due to high number of cores

[David Marchand]

Hello,

On Fri, Sep 23, 2022 at 9:06 AM Abdullah Ömer Yamaç
<omer.yamac at ceng.metu.edu.tr> wrote:
>
> In this patch we suggest a new name for lcore-worker.
> In case of more than 99 logical cores, name is truncated
> (length is restricted to 16 characters, including the
> terminating null byte ('\0')) and it makes hard to follow threads.
>
> Signed-off-by: Abdullah Ömer Yamaç <omer.yamac at ceng.metu.edu.tr>
> Acked-by: Stephen Hemminger <stephen at networkplumber.org>

- Thanks, good catch.

Some comments though.
What matters is the lcore index, not the core/lcore count.
The commitlog could probably describe this better.

For example, this issue can be triggered with --lcores=0,10 at 1,100 at 2
and here we only have three lcores.
$ cat /proc/$(pidof dpdk-testpmd)/task/*/comm
dpdk-testpmd
eal-intr-thread
rte_mp_handle
lcore-worker-10
lcore-worker-10
telemetry-v2
telemetry-v1


And what do you think of following title:
"eal: fix thread names for high order lcores"

Can you update the release notes?


- Question to stable maintainers:
Do you think we should backport this fix?
As you can see below, this change affects EAL thread names, maybe some
users are monitoring them based on the names...


>
> ---
> Cc: David Marchand <david.marchand at redhat.com>
> ---
>  lib/eal/freebsd/eal.c | 2 +-
>  lib/eal/linux/eal.c   | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/lib/eal/freebsd/eal.c b/lib/eal/freebsd/eal.c
> index ee5c929da8..a1bb5363b1 100644
> --- a/lib/eal/freebsd/eal.c
> +++ b/lib/eal/freebsd/eal.c
> @@ -817,7 +817,7 @@ rte_eal_init(int argc, char **argv)
>
>                 /* Set thread_name for aid in debugging. */
>                 snprintf(thread_name, sizeof(thread_name),
> -                               "lcore-worker-%d", i);
> +                               "rte-worker-%d", i);
>                 rte_thread_setname(lcore_config[i].thread_id, thread_name);
>
>                 ret = pthread_setaffinity_np(lcore_config[i].thread_id,
> diff --git a/lib/eal/linux/eal.c b/lib/eal/linux/eal.c
> index 46bf52cef0..9a168b7773 100644
> --- a/lib/eal/linux/eal.c
> +++ b/lib/eal/linux/eal.c
> @@ -1248,7 +1248,7 @@ rte_eal_init(int argc, char **argv)
>
>                 /* Set thread_name for aid in debugging. */
>                 snprintf(thread_name, sizeof(thread_name),
> -                       "lcore-worker-%d", i);
> +                       "rte-worker-%d", i);
>                 ret = rte_thread_setname(lcore_config[i].thread_id,
>                                                 thread_name);
>                 if (ret != 0)
> --
> 2.27.0
>

Merci !

-- 
David Marchand