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=-16.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 2D563C433C1 for ; Wed, 24 Mar 2021 09:33:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CEC0D61A0B for ; Wed, 24 Mar 2021 09:33:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235076AbhCXJc3 (ORCPT ); Wed, 24 Mar 2021 05:32:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:58470 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236243AbhCXJcH (ORCPT ); Wed, 24 Mar 2021 05:32:07 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4031A61A07; Wed, 24 Mar 2021 09:32:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1616578326; bh=H1ZA9F/FjCNa3FF4dTmgJwcqG8AEiMqEkQhzmBz7a8g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QwL4d+3Wp7SsbuLFveFYAjv5S6bMwP+MMxtAZE+O8WrTjvo9tiYOj1q/1zl/7Hgb4 nsdlMwcfqIGDCGHrC7UTfAAnn1nDzT7M1n/jQ2ETy/tV+s7pYNj4/QEhuDeMvJFRE5 u/js21ec3KEmAW6QncrDxz4VtlyZ2CEFyIaW5k9Hu/GONfIJMBQHlsX4R7VzU4ZdB5 zwSpYWIXAwL6LYoIc2x6KW4EceFDHueLO6edEmYdLrhmsCLNwbzLu8yVUCPDqA/idF SO87JOPUEhj5u+I4q/5/ZgUg45GhLCtj2t5F/zf62WC4iG4yRKkoGrQJuSV6ze7fxS QpH0tWFNgiolA== Date: Wed, 24 Mar 2021 11:32:03 +0200 From: Leon Romanovsky To: Dmitry Vyukov Cc: davem@davemloft.net, edumazet@google.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] net: make unregister netdev warning timeout configurable Message-ID: References: <20210323064923.2098711-1-dvyukov@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210323064923.2098711-1-dvyukov@google.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, Mar 23, 2021 at 07:49:23AM +0100, Dmitry Vyukov wrote: > netdev_wait_allrefs() issues a warning if refcount does not drop to 0 > after 10 seconds. While 10 second wait generally should not happen > under normal workload in normal environment, it seems to fire falsely > very often during fuzzing and/or in qemu emulation (~10x slower). > At least it's not possible to understand if it's really a false > positive or not. Automated testing generally bumps all timeouts > to very high values to avoid flake failures. > Add net.core.netdev_unregister_timeout_secs sysctl to make > the timeout configurable for automated testing systems. > Lowering the timeout may also be useful for e.g. manual bisection. > The default value matches the current behavior. > > Signed-off-by: Dmitry Vyukov > Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=211877 > Cc: netdev@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > > --- > Changes since v1: > - use sysctl instead of a config > --- > Documentation/admin-guide/sysctl/net.rst | 11 +++++++++++ > include/linux/netdevice.h | 1 + > net/core/dev.c | 6 +++++- > net/core/sysctl_net_core.c | 10 ++++++++++ > 4 files changed, 27 insertions(+), 1 deletion(-) > Thanks, Reviewed-by: Leon Romanovsky