Re: [PATCH v4] eal/unix: optimize thread creation

[David Marchand <david.marchand@redhat.com>]

On Mon, Nov 4, 2024 at 9:57 AM David Marchand <david.marchand@redhat.com> wrote:
>
> Setting the cpu affinity of the child thread from the parent thread is
> racy when using pthread_setaffinity_np, as the child thread may start
> running and initialize before affinity is set.
>
> On the other hand, setting the cpu affinity from the child thread itself
> may fail, so the parent thread waits for the child thread to report
> whether this call succeeded.
>
> This synchronisation point resulted in a significant slow down of
> rte_thread_create() (as seen in the lcores_autotest unit tests, in OBS
> for some ARM systems).
>
> Another option for setting cpu affinity is to use the not portable
> pthread_attr_setaffinity_np available in FreeBSD and glibc,
> but not available in musl.
>
> Fixes: b28c6196b132 ("eal/unix: fix thread creation")
> Cc: stable@dpdk.org
>
> Signed-off-by: David Marchand <david.marchand@redhat.com>
> Acked-by: Luca Boccassi <bluca@debian.org>
> Acked-by: Stephen Hemminger <stephen@networkplumber.org>
> Acked-by: Chengwen Feng <fengchengwen@huawei.com>

CI looks good, and I tested manually in FreeBSD and ARM+OBS.

Applied, thanks.


-- 
David Marchand