netdev - Re: [PATCH net-next v6 2/2] xsk: move cq_cached_prod_lock to avoid touching a cacheline in sending path

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <9f0fffcd-8e2a-4ae1-b89d-ae73dba9e1be@redhat.com>
Date: Thu, 8 Jan 2026 09:55:07 +0100
From: Paolo Abeni <pabeni@...hat.com>
To: Jason Xing <kerneljasonxing@...il.com>, davem@...emloft.net,
 edumazet@...gle.com, kuba@...nel.org, bjorn@...nel.org,
 magnus.karlsson@...el.com, maciej.fijalkowski@...el.com,
 jonathan.lemon@...il.com, sdf@...ichev.me, ast@...nel.org,
 daniel@...earbox.net, hawk@...nel.org, john.fastabend@...il.com
Cc: bpf@...r.kernel.org, netdev@...r.kernel.org,
 Jason Xing <kernelxing@...cent.com>
Subject: Re: [PATCH net-next v6 2/2] xsk: move cq_cached_prod_lock to avoid
 touching a cacheline in sending path

On 1/4/26 2:21 AM, Jason Xing wrote:
> diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
> index 6bf84316e2ad..cd5125b6af53 100644
> --- a/net/xdp/xsk_buff_pool.c
> +++ b/net/xdp/xsk_buff_pool.c
> @@ -91,7 +91,7 @@ struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
>  	INIT_LIST_HEAD(&pool->xsk_tx_list);
>  	spin_lock_init(&pool->xsk_tx_list_lock);
>  	spin_lock_init(&pool->cq_prod_lock);
> -	spin_lock_init(&pool->cq_cached_prod_lock);
> +	spin_lock_init(&xs->cq_tmp->cq_cached_prod_lock);
>  	refcount_set(&pool->users, 1);

Very minor nit: moving the init later, after:

	pool->cq = xs->cq_tmp;

would avoid touching a '_tmp' field, which looks strange.

Please do not resubmit just for this. Waiting a little longer for
Magnus, Maciej or Stanislav ack.

/P