From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E89DC2BE655 for ; Mon, 10 Nov 2025 17:27:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762795658; cv=none; b=M9/YqF03sc7x7rw7Q/ryoxLUtdqz7EV9JgwFMieYuLizJAVBCdOh1oeFHY/S0r3DNy2/SXLiC4lxrSTiQvHz17Mi5WQaHn5UUDg9f/7eUpxbhLqDXc3cObHCZIKMXlHAdsVGBS5Y8ihyP4v2NcQnGLFawx/J62pjvp6qMVf68/M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762795658; c=relaxed/simple; bh=qletO7ZLb6ssek75YbmCFHdcAca6r9JGiXOKUOzxs6A=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=hqM5tn0oPxyVHsg/MNmaql/9rkOnKKedWFdDcETiQVk5KuuCt+rcgpR5vbsVzr2Fb3N0kJMy82D+UDNmwe6/WdRZc321qjKFf0FsRshj3W9H3OONCrM9JDauanfZzVuClZpMUuSWQjdq9he60MF9eHS1bgG3lP6tzbIYBcJwJ0I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=kdA61oTN; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="kdA61oTN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0BA6CC4CEF5; Mon, 10 Nov 2025 17:27:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762795657; bh=qletO7ZLb6ssek75YbmCFHdcAca6r9JGiXOKUOzxs6A=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=kdA61oTNFH3cvOCtIisu64XCtdLs9ILS4dt/c3lK1aEs4u6kYw1NozIr8kytUYstD V76QOBTj0syQjQqRuAhOvRue38K/dUmZ7Ml2i6Fc7ysv5N4W4BCwOK5gtaAlz04sRk mApoPSS5Frc+cr7ZfYuoQ2ogqg57ia0GhYKf7x5EF1/J76sroE6TRnVD+//246s+YY /c+KwX5uSuAI/dw2MEBFljd+8LMFnkGew0viJTs+i/xQ4o+Osed/1YgxknQmX7vXYl Wi9BxgkGDYkCKuyj1aj5m8+BUGcO3jMpQ8GsCDFVN82Vw7u+lrLFp2th3yEBwfDDpS 9FYTj8QSZoKfQ== Date: Mon, 10 Nov 2025 09:27:36 -0800 From: Jakub Kicinski To: Eric Dumazet Cc: "David S . Miller" , Paolo Abeni , Simon Horman , Jamal Hadi Salim , Cong Wang , Jiri Pirko , Toke =?UTF-8?B?SMO4aWxhbmQtSsO4cmdlbnNlbg==?= , Kuniyuki Iwashima , Willem de Bruijn , netdev@vger.kernel.org, eric.dumazet@gmail.com Subject: Re: [PATCH net-next 00/10] net_sched: speedup qdisc dequeue Message-ID: <20251110092736.5642f227@kernel.org> In-Reply-To: References: <20251110094505.3335073-1-edumazet@google.com> <20251110084432.7fdf647b@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Mon, 10 Nov 2025 09:15:46 -0800 Eric Dumazet wrote: > On Mon, Nov 10, 2025 at 8:44=E2=80=AFAM Jakub Kicinski = wrote: > > > > On Mon, 10 Nov 2025 09:44:55 +0000 Eric Dumazet wrote: =20 > > > Avoid up to two cache line misses in qdisc dequeue() to fetch > > > skb_shinfo(skb)->gso_segs/gso_size while qdisc spinlock is held. > > > > > > Idea is to cache gso_segs at enqueue time before spinlock is > > > acquired, in the first skb cache line, where we already > > > have qdisc_skb_cb(skb)->pkt_len. > > > > > > This series gives a 8 % improvement in a TX intensive workload. > > > > > > (120 Mpps -> 130 Mpps on a Turin host, IDPF with 32 TX queues) =20 > > > > According to CI this breaks a bunch of tests. > > > > https://netdev.bots.linux.dev/contest.html?branch=3Dnet-next-2025-11-10= --12-00 > > > > I think they all hit: > > > > [ 20.682474][ T231] WARNING: CPU: 3 PID: 231 at ./include/net/sch_ge= neric.h:843 __dev_xmit_skb+0x786/0x1550 =20 >=20 > Oh well, I will add this in V2, thank you ! >=20 > diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h > index b76436ec3f4aa412bac1be3371f5c7c6245cc362..79501499dafba56271b9ebd97= a8f379ffdc83cac > 100644 > --- a/include/net/sch_generic.h > +++ b/include/net/sch_generic.h > @@ -841,7 +841,7 @@ static inline unsigned int qdisc_pkt_segs(const > struct sk_buff *skb) > u32 pkt_segs =3D qdisc_skb_cb(skb)->pkt_segs; >=20 > DEBUG_NET_WARN_ON_ONCE(pkt_segs !=3D > - skb_is_gso(skb) ? skb_shinfo(skb)->gso_seg= s : 1); > + (skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1)= ); > return pkt_segs; > } Hm, I think we need more.. The non-debug workers are also failing and they have DEBUG_NET=3Dn Looks like most of the non-debug tests are tunnel and bridge related. VxLAN, GRE etc.=20 https://netdev.bots.linux.dev/contest.html?pass=3D0&branch=3Dnet-next-2025-= 11-10--12-00&executor=3Dvmksft-forwarding