From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E12A4C433DB for ; Mon, 8 Mar 2021 18:29:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ADB666516B for ; Mon, 8 Mar 2021 18:29:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230143AbhCHS31 (ORCPT ); Mon, 8 Mar 2021 13:29:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52546 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231254AbhCHS3B (ORCPT ); Mon, 8 Mar 2021 13:29:01 -0500 Received: from mout-p-101.mailbox.org (mout-p-101.mailbox.org [IPv6:2001:67c:2050::465:101]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EDBCFC06174A for ; Mon, 8 Mar 2021 10:29:00 -0800 (PST) Received: from smtp2.mailbox.org (smtp2.mailbox.org [80.241.60.241]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-101.mailbox.org (Postfix) with ESMTPS id 4DvRgY4wpDzQjwp; Mon, 8 Mar 2021 19:28:57 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mailbox.org; h= content-transfer-encoding:content-type:content-type:mime-version :references:in-reply-to:message-id:subject:subject:from:from :date:date:received; s=mail20150812; t=1615228132; bh=xe3cIOx7yk 5hGgWBHXhtvAV+EMp6+77X4FIRKW11beM=; b=dQvE9TqvzIDA4VAFIQWGoR0n8m c3DlRuPvXviWpdSV5ImU3lvMh6i4gXYHzCqro7eGX+ynkmODsPsIbwGVoBuZuEzu 7moTwprSesraYVB9kqVpuKk7o3PXDw2Rm72wNepgzsDzYS/xlMO8Jv/1ZxYojqcm exjXX6KWML1rBoY9QXs1yfP7cfSqaPdfTvMkP47LZ07vYBrhlnM2qZ2Za9jwToa1 WEORBOFHmvWXbMC0u/ijI/sYxu93u9WrrC8V10MbWloQ+h3ZORMPZY7NOYfZGCBA rQ7iGuH1AZUiolLAfKrFxU3+4G8qU6CdeQtK+ceJWSbmjz6xhN7x5+fzUEVQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mailbox.org; s=mail20150812; t=1615228133; 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=6wTcrrq3uEtYYMJGRkofwY/gJu+CXcCgsaup1py6NVo=; b=fN3PP/oQ0Fc+0XZG18N631AofsCNKhYED9sw+N/e5qVAOg4WQGdy8yPdTxWxaoE4eX8OzU H9gFpSV/V7uAWix5zc3NGjq71ybt3jMPu+fdKp2ZP4GQLRrVPZmOPc7xoHLgh0HrPKQe8k UBYubNzqb/OBkn4uiEfD3ztl1hle8fg0Fa6e0nk8fdgMlvphZC6NR9SkjMOwtOckwRu0+A Weg/8GEyMKQC5rKKinbjEwdpk1KxbgcBi3mYahKBC54k2DDER6U+IkkbNLo7NI4kBMapck dQensBWSz4S3sME1d3xJ74Z5YoDJThXsNzV4EOuCJZVH8NHyMvBNmLTaL01QUA== X-Virus-Scanned: amavisd-new at heinlein-support.de Received: from smtp2.mailbox.org ([80.241.60.241]) by spamfilter01.heinlein-hosting.de (spamfilter01.heinlein-hosting.de [80.241.56.115]) (amavisd-new, port 10030) with ESMTP id 4QII7ZAtGOro; Mon, 8 Mar 2021 19:28:52 +0100 (CET) Date: Mon, 8 Mar 2021 19:28:49 +0100 From: "Erhard F." To: "Ahmed S. Darwish" Cc: Jakub Kicinski , "netdev@vger.kernel.org" , Sebastian Andrzej Siewior , Peter Zijlstra Subject: Re: seqlock lockdep false positives? Message-ID: <20210308192849.153454f7@yea> In-Reply-To: References: <20210303164035.1b9a1d07@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-MBO-SPAM-Probability: X-Rspamd-Score: -3.49 / 15.00 / 15.00 X-Rspamd-Queue-Id: AB4CD180D X-Rspamd-UID: 4b7a61 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sun, 7 Mar 2021 10:20:08 +0100 "Ahmed S. Darwish" wrote: > @Erhard, can you please try below patch? Just want to confirm if this > theory has any validity to it: > > diff --git a/drivers/net/ethernet/realtek/8139too.c b/drivers/net/ethernet/realtek/8139too.c > index 1e5a453dea14..c0dbb0418e9d 100644 > --- a/drivers/net/ethernet/realtek/8139too.c > +++ b/drivers/net/ethernet/realtek/8139too.c > @@ -715,6 +715,11 @@ static const unsigned int rtl8139_rx_config = > static const unsigned int rtl8139_tx_config = > TxIFG96 | (TX_DMA_BURST << TxDMAShift) | (TX_RETRY << TxRetryShift); > > +#if BITS_PER_LONG==32 && defined(CONFIG_SMP) > +static struct lock_class_key rx_stats_key; > +static struct lock_class_key tx_stats_key; > +#endif > + > static void __rtl8139_cleanup_dev (struct net_device *dev) > { > struct rtl8139_private *tp = netdev_priv(dev); > @@ -794,8 +799,17 @@ static struct net_device *rtl8139_init_board(struct pci_dev *pdev) > > pci_set_master (pdev); > > - u64_stats_init(&tp->rx_stats.syncp); > - u64_stats_init(&tp->tx_stats.syncp); > +#if BITS_PER_LONG==32 && defined(CONFIG_SMP) > + dev_warn(d, "Manually intializing tx/rx stats sequence counters\n"); > + > + tp->rx_stats.syncp.seq.sequence = 0; > + lockdep_set_class_and_name(&tp->rx_stats.syncp.seq, > + &rx_stats_key, "RX stats"); > + > + tp->tx_stats.syncp.seq.sequence = 0; > + lockdep_set_class_and_name(&tp->tx_stats.syncp.seq, > + &tx_stats_key, "TX stats"); > +#endif Hi Ahmed! With your patch on top of 5.12-rc2 the lockdep splat is gone in the kernel dmesg and I only get: [...] 8139too: 8139too Fast Ethernet driver 0.9.28 8139too 0000:00:0f.0: Manually intializing tx/rx stats sequence counters 8139too 0000:00:0f.0 eth0: RealTek RTL8139 at 0x(ptrval), 00:30:1b:2f:2c:58, IRQ 18 [...] Trying Peter's patch next.