From nobody Thu Jun 25 06:44:17 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 34C66399377 for ; Mon, 20 Apr 2026 10:30:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776681018; cv=none; b=qMGtpBIPgJTyIhNpASZd32nperYnTmmZe+rSc9vsVxDOrrp0FVTr5WHPcI8Cdj/J9V5t2wTJmFqe3u9WKGgwB560s6AU26ZGEXAzJEP/Tk1Z3HpPwl8Y1JS2EmNn7VVoAIPwcpMEEMCM9RbAnXffskP2PULav1jlIKyHjoYOQCA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776681018; c=relaxed/simple; bh=i0RrDDrd+hFVsmXhX6F7M++BkBVutE2T0LexjliuH+M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:content-type; b=V7r+g0sRCNpSxxZlWVM7T0ud7Ek1BntIRLyXd9N4JG4tdFfShJUZCJQFEWoaM046/DsxnWhII9uiMCG5S8r0z7hrK1m6pVdNPYBxv9IjQWx79OjACORbAOgOvGoVMkyd+nJf0Wce4oXRIAA65JgIFC7OMY6l6tHBUeWr251lS+w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=WZN9UeA6; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="WZN9UeA6" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1776681016; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=5yxSuS76vMLmzgVW7whv3CCFI8Q3HZjI3RSdYor1u5Q=; b=WZN9UeA6Cc4aQRlNGh9AiPfsOIiWlWuQSxb0T0FmoCzqJYK1kLj7UOJpfh4mxPwpXls8gj zqPfET33ONxAP+jeydh/eXtOHXsM1MDkmAnuU8URbqG3GgU4Hwdpbv7qB9wd/zqn/DPihb LrGW73+vD4L1uaHN2V5Vub5LdQOLaak= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-473-ZxqIpUddP4O6fJQmaKtNOw-1; Mon, 20 Apr 2026 06:30:13 -0400 X-MC-Unique: ZxqIpUddP4O6fJQmaKtNOw-1 X-Mimecast-MFC-AGG-ID: ZxqIpUddP4O6fJQmaKtNOw_1776681012 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 040B9180036E; Mon, 20 Apr 2026 10:30:12 +0000 (UTC) Received: from gerbillo.redhat.com (unknown [10.44.33.233]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 5DBFB195608E; Mon, 20 Apr 2026 10:30:09 +0000 (UTC) From: Paolo Abeni To: mptcp@lists.linux.dev Cc: yangang@kylinos.cn, geliang@kernel.org, matttbe@kernel.org Subject: [RFC PATCH 6/6] mptcp: unclone skbs before coalescing them, when needed Date: Mon, 20 Apr 2026 12:29:30 +0200 Message-ID: In-Reply-To: References: Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: WP-GE_HBnWEgsZgRzJI0yEVPi-dgB5bEpry1FWTfBlg_1776681012 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8"; x-default="true" The self-test can trigger skb coalescing on clones skb, as the forward path uses only veth devices. That in turn prevents coalescing making memory pressure scenario more extreme. Signed-off-by: Paolo Abeni --- Possibly we could obtain the same effect with some netem magic, would be better. --- net/mptcp/protocol.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 8ddd4bb5172e..42af9f9e935d 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -162,6 +162,7 @@ static bool __mptcp_try_coalesce(struct sock *sk, struc= t sk_buff *to, if (unlikely(MPTCP_SKB_CB(to)->cant_coalesce) || MPTCP_SKB_CB(from)->offset || ((to->len + from->len) > max(U16_MAX, (limit >> 3))) || + (skb_cloned(to) && skb_unclone(to, GFP_ATOMIC)) || !skb_try_coalesce(to, from, fragstolen, delta)) return false; =20 --=20 2.53.0