From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.10]) (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 9E3AD248F4B; Wed, 19 Aug 2026 21:16:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787174175; cv=none; b=b9IZ6JCytojbkiXrNMbHDD8ycMPRPtHJpPlVBNMONvIkrfrDD42UAV+erQkJLVfVESvz8BNhcoYoF1PVv4fd9qsvIAjvVDAj707DGNQY4Rp2aama281K/SbcyiqQYQv4bm8H7M+uG8lflYqxoFDewvLNan0dGq3C0U0E1eouCT0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787174175; c=relaxed/simple; bh=znKp6FFW6e4vloCf/TZGsoTX7/wCAKLPkbIxWejDXZI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=tyza0xAt6IOlMiiFnvcVoaPDKcY7cOKcZxqcCKxd6FXTrj5+/XSFUujmWjXgkszbFtOXqJZ33bXXQc0Nn7BrrW5aCpExVVf2Tk/KlosfiBoF7nRluwPCbUuNKHg4GPTw7j0PoEzPHcjKH+7l74gtUxzpNz8yRRDLEJ4z/BMxpo0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=OJcAuzQV; arc=none smtp.client-ip=192.198.163.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="OJcAuzQV" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1787174174; x=1818710174; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=znKp6FFW6e4vloCf/TZGsoTX7/wCAKLPkbIxWejDXZI=; b=OJcAuzQVCiid9WekaK6hBYfF1OCg2GB+rdWVQ+9gHsEewgCbsvB6B+Ie 1Pl5L9ZqvuOF//ZUnT+94QCOLpwpHhakrCOmISK5vmZCTAMVh38RReCoY 7VRatNx9r/y0IP4zjspNvxRpzgQR7DMeQmWaMc82c5v5Xurw/KmxdKT5A zI+i0vYEzcHJrUasYrvwd19J2zQX7R+reM7D9BC5Z0GDtmlZnCSWetPyu BiE73qr9MXOLEcpQ6AF26ZoreaULC9WnbPZH164+9g4DS7NvDAcVbB4vA GxpeOV0fPbwIR6VrSl3UNVUaTLL3hZS8OaTH4d8Y20QvsFkq+7qjTMZ3e w==; X-CSE-ConnectionGUID: UgQhkDjtTdi9ZuH/VOLQhA== X-CSE-MsgGUID: DwTgW0g8RF+vPzrh8rCg8w== X-IronPort-AV: E=McAfee;i="6800,10657,11880"; a="99060871" X-IronPort-AV: E=Sophos;i="6.25,232,1779174000"; d="scan'208";a="99060871" Received: from orviesa003.jf.intel.com ([10.64.159.143]) by fmvoesa104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Aug 2026 14:16:12 -0700 X-CSE-ConnectionGUID: hfLa0FnjSjWDP00ZujihIw== X-CSE-MsgGUID: vWx5l7aUSFyYCRFDUq4TpA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,232,1779174000"; d="scan'208";a="269179100" Received: from aschende-mobl.amr.corp.intel.com (HELO [10.125.108.13]) ([10.125.108.13]) by ORVIESA003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Aug 2026 14:16:11 -0700 Message-ID: <5571c4ba-aa12-442a-aa2f-3b3e073e1305@intel.com> Date: Wed, 19 Aug 2026 14:16:09 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net 1/4] NTB: ntb_transport: Recycle TX entries before client callbacks To: Koichiro Den , Jon Mason , Allen Hubbe , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: ntb@lists.linux.dev, netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260817053519.4135287-1-den@valinux.co.jp> <20260817053519.4135287-2-den@valinux.co.jp> From: Dave Jiang Content-Language: en-US In-Reply-To: <20260817053519.4135287-2-den@valinux.co.jp> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 8/16/26 10:35 PM, Koichiro Den wrote: > ntb_tx_copy_callback() invokes the client callback before returning the > entry to tx_free_q. The callback may wake a stopped client queue, only > for the next enqueue to find no local entry and return -EBUSY. The window > is narrow, but the retry is unnecessary. > > Save the callback data and length, then return the entry to tx_free_q > before invoking the client. A completion callback then means both the > client buffer and transport entry are ready for reuse. > > Fixes: fce8a7bb5b4b ("PCI-Express Non-Transparent Bridge Support") > Cc: stable@vger.kernel.org > Signed-off-by: Koichiro Den Reviewed-by: Dave Jiang > --- > drivers/ntb/ntb_transport.c | 23 ++++++++++++++--------- > 1 file changed, 14 insertions(+), 9 deletions(-) > > diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c > index f59f926d4bfa..e92b96f4afad 100644 > --- a/drivers/ntb/ntb_transport.c > +++ b/drivers/ntb/ntb_transport.c > @@ -1719,9 +1719,16 @@ static void ntb_transport_rxc_db(unsigned long data) > static void ntb_tx_copy_callback(void *data, > const struct dmaengine_result *res) > { > + struct ntb_payload_header __iomem *hdr; > struct ntb_queue_entry *entry = data; > - struct ntb_transport_qp *qp = entry->qp; > - struct ntb_payload_header __iomem *hdr = entry->tx_hdr; > + struct ntb_transport_qp *qp; > + unsigned int len; > + void *cb_data; > + > + qp = entry->qp; > + hdr = entry->tx_hdr; > + cb_data = entry->cb_data; > + len = entry->len; > > /* we need to check DMA results if we are using DMA */ > if (res) { > @@ -1768,15 +1775,13 @@ static void ntb_tx_copy_callback(void *data, > * "link down" or similar. Since no payload is being sent in these > * cases, there is nothing to add to the completion queue. > */ > - if (entry->len > 0) { > - qp->tx_bytes += entry->len; > - > - if (qp->tx_handler) > - qp->tx_handler(qp, qp->cb_data, entry->cb_data, > - entry->len); > - } > + if (len > 0) > + qp->tx_bytes += len; > > ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q); > + > + if (len > 0 && qp->tx_handler) > + qp->tx_handler(qp, qp->cb_data, cb_data, len); > } > > static void ntb_memcpy_tx_on_stack(struct ntb_queue_entry *entry, void __iomem *offset)