From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 619054AA1CD; Mon, 19 Oct 2026 09:58:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792403903; cv=none; b=tsT+v52/UfBCDLOG7GgrgOyJMh7R7YIg41icmPg7RrisAPLWb/Ow8i7rB/pT/NO6XURA6otcLp6frYhl6Vxw+yDHu8fiuL60sqOWRH1HdhFAMhJy8o8DAf68GcnedH9ee3z3miy/INcs/huhi2R7hS/TvJ1AYnR2zajvIyCaRnU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792403903; c=relaxed/simple; bh=7STzAZVE2icKcOUDIcTfyyUyejv1yzD1Rq+SGFadgCQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=qIUSZVKR1RLzjgSJp8821MdOWLF41nYXtuzoch8/uiO/mAFiW8EtywyFsztoOCzWlHtlLPF00BJNZv9NvxxrtGWlpFbaq/5wFQsFTFbi6W9/CGVGAd8HfTHVOOSBshmxkTZd9P5VbaiwxhMMUyGYnIZ3dZHND9YE4XA01RVf+V8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IsQ8XZY0; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="IsQ8XZY0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6C34A1F000C4; Mon, 19 Oct 2026 09:58:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792403902; bh=c3RnrIDDX2/I7bSPgPTL7arfKC/4On1YTWVqBC2tUVU=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=IsQ8XZY0yUaSWEvovFDg/M5FMNYyJxGIXCCnAbnb3D+poYtT8r9MToxAmx3Zj4aY3 1R629wzDJZqXv2o1IGeku8h0a0O+OvS2d1WpjA89ig3XqrrflqF+CkAitgC7lZYMVI +LyXeQ/Pwx8c1yYLrhYUvVQbhxohK5sLp8sgrNcBlqwkLGB6DLflxAVEMPdO0x6rLz UUdCxHc9Qk9/W1VZ8zA3N5iv/1Tsj3S+Jk2QpNBYGr0hjyuX2idiOLLWCg1zg8xkhW SI1I7unpPdodJNO98KG2fmFLw2k+McAjZmWg1V13OUKiHlTOc+jbm+TROOCXUwza+k Vthnlfzaj+nUg== Message-ID: <746ba331-0a9f-46ed-8faf-d432bec5c8c6@kernel.org> Date: Mon, 19 Oct 2026 11:58:16 +0200 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net 1/2] veth: schedule the peer's NAPI after XDP_TX when only GRO is enabled To: Lorenzo Bianconi , Tianyi Gao Cc: netdev@vger.kernel.org, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@kernel.org, kuba@kernel.org, pabeni@redhat.com, toke@redhat.com, horms@kernel.org, bpf@vger.kernel.org, shuah@kernel.org, kernel-team@cloudflare.com, ast@kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com, sdf@fomichev.me, linux-kselftest@vger.kernel.org, bochaolucky@gmail.com, toshiaki.makita1@gmail.com References: <20261016214217.16942-1-tianyi@cloudflare.com> <20261016214217.16942-2-tianyi@cloudflare.com> Content-Language: en-US From: Jesper Dangaard Brouer In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 10/18/26 11:08, Lorenzo Bianconi wrote: >> veth_xdp_xmit() queues XDP_TX frames on the peer's ring if the peer has >> NAPI. A peer with GRO enabled and no XDP program also has NAPI. >> >> veth_xdp_flush() then schedules the peer's NAPI, but only if the peer's >> xdp_prog is set, so for such a peer the frames are never processed. >> Nothing else schedules that NAPI by default. >> >> Once the ring is full, every XDP_TX frame is dropped, and so are the >> skbs that veth_xmit() queues on the same ring. >> >> Commit 0e672f306a28 ("veth: check for NAPI instead of xdp_prog before >> xmit of XDP frame") changed the check in veth_xdp_xmit() but not the one >> in veth_xdp_flush(). Make veth_xdp_flush() check the napi pointer >> instead of xdp_prog, as veth_xdp_xmit() does. >> >> Fixes: 0e672f306a28 ("veth: check for NAPI instead of xdp_prog before xmit of XDP frame") >> Signed-off-by: Tianyi Gao > > Acked-by: Lorenzo Bianconi LGTM Acked-by: Jesper Dangaard Brouer >> --- >> drivers/net/veth.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/net/veth.c b/drivers/net/veth.c >> index 643b97dc5245..9405ffac598a 100644 >> --- a/drivers/net/veth.c >> +++ b/drivers/net/veth.c >> @@ -612,7 +612,7 @@ static void veth_xdp_flush(struct veth_rq *rq, struct veth_xdp_tx_bq *bq) >> rcv_priv = netdev_priv(rcv); >> rcv_rq = &rcv_priv->rq[veth_select_rxq(rcv)]; >> /* xdp_ring is initialized on receive side? */ >> - if (unlikely(!rcu_access_pointer(rcv_rq->xdp_prog))) >> + if (unlikely(!rcu_access_pointer(rcv_rq->napi))) >> goto out; >> >> __veth_xdp_flush(rcv_rq); >> -- >> 2.55.0 >>