Re: [PATCH v1] net/mlx5: fix probe optimization race condition

[Thomas Monjalon <thomas@monjalon.net>]

28/08/2025 06:49, rongwei liu:
> 
> On 2025/8/28 12:40, Stephen Hemminger wrote:
> > On Thu, 28 Aug 2025 06:21:34 +0300
> > Rongwei Liu <rongweil@nvidia.com> wrote:
> > 
> >> With dedicated RDMA link monitor, there are two threads
> >> which can update the IB device port information.
> >>
> >> Add a new flag to avoid the race condition. Update should
> >> go through RDMA link monitor once ready.
> >>
> >> Fixes: 51fb5c40c826 ("net/mlx5: optimize device probing")
> >> Cc: rongweil@nvidia.com
> >> Cc: stable@dpdk.org
> >> Signed-off-by: Rongwei Liu <rongweil@nvidia.com>
> >> Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
> >> ---
> > 
> > If variable is modified (with out locking) on two threads it
> > needs to atomic or volatile.
> Exactly. Before this patch, it' user responsebility to seperate probe probing and sf manipualtion.
> Obviously, customer didn't follow this very well.
> Now logic change to:
> 1. Update all port information in probing thread.
> 2. Probe thread initiate the dedicated rdma monitor thread. Once ready, all port update will go to this thread.
> 3. Next port probing won't trigger PMD port information update.
> 
> No lock is required then.

This is the kind of info we need in a commit log.
Please make a v2, thanks.