From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay6-d.mail.gandi.net (relay6-d.mail.gandi.net [217.70.183.198]) (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 59016263F34 for ; Sat, 25 Apr 2026 18:50:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.198 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777143055; cv=none; b=arG+xVUE1nI9sXGGNCDTE9W1/j9lgY7x3L0mOjB5X+33iQ2gdAWN1tiUMyHM4dikMTzsDliQRaV4fSbbWy3hPZREYNaF+k2qt/RoaBZ0u6aNQ+ryYI85h5JQrFQtdJkRYCAxatT0nwi5bGGsnrGaWlUzHOj9KOAUPjOhagFTLuQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777143055; c=relaxed/simple; bh=pRci5jmRWpusb+p+d+kgLsjl2B2c08PQh7nHfwDQ7oU=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=gWd1mm/RYKNTbshQrY9yvutKxzZiq4TbPhFkcU3f4rfm82GuqUMxpzlrcUIgCsZm/VhiWV6XrwYRT8f2AuXKx6zZSKX1F8S6svhU9m6GAPqeuxWj0YlD/dKSFtl/mwVdjj0yUQPpjC7On+YRqIce0tUoj7RhDBaSvJ/KfU/0eCw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=xenomai.org; spf=pass smtp.mailfrom=xenomai.org; dkim=pass (2048-bit key) header.d=xenomai.org header.i=@xenomai.org header.b=kTbCupue; arc=none smtp.client-ip=217.70.183.198 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=xenomai.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=xenomai.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=xenomai.org header.i=@xenomai.org header.b="kTbCupue" Received: by mail.gandi.net (Postfix) with ESMTPSA id D961D3ED66; Sat, 25 Apr 2026 18:50:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=xenomai.org; s=gm1; t=1777143051; 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: in-reply-to:in-reply-to:references:references; bh=2e3p+QUmYolt2o9+JmQVds4PTbbvFGtTJQJMoz5d90E=; b=kTbCupueJywocbPM+n3MQpSHsS6+wTAQ8UMBxXm5aHOLn4cZqxts+uyfr/bY/TT/fgD6Zq qaZkKNOxfZALtYjPmqm5auHXH/gBdhwSoIze2X9MtKCzYi6uQFQZsC+t+gsubVtyLwoibp +geOlEA4a0nPH28sM1y4oV/yFW0JyFcMiZwjLvbtRdtG+Muiv3+qNwNekwmSwlpqXRJ9o+ NtPmnG4HeSCoxuQAMlEBfDRj/W0jjQDcFVtJU3QWge07tJztJiHd+pB/CA/KyvQB5VGEmv ON/XUsx2/A6oF/LardnANzIowaQejs8fDoiAdkMX9RfY6ZXTwXI4+cGBy83CRA== From: Philippe Gerum To: Hannes Diethelm Cc: xenomai@lists.linux.dev Subject: Re: [EVL] Kernel WARNING: notifier callback netevent_handler already registered In-Reply-To: <8e08bda6-1fed-4a5a-9bb3-74f019b05855@gmail.com> (Hannes Diethelm's message of "Sat, 25 Apr 2026 18:24:14 +0200") References: <8e08bda6-1fed-4a5a-9bb3-74f019b05855@gmail.com> User-Agent: mu4e 1.12.12; emacs 30.2 Date: Sat, 25 Apr 2026 20:50:50 +0200 Message-ID: <87340ij2lx.fsf@xenomai.org> Precedence: bulk X-Mailing-List: xenomai@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain X-GND-Sasl: rpm@xenomai.org X-GND-State: clean X-GND-Score: -100 X-GND-Cause: 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 Hannes Diethelm writes: > Hello > > There is a Kernel WARNING: "notifier callback netevent_handler already registered right after boot". It is repeated 5 times. > > Config: > Debian Trixie with xfce4 Desktop > libevl: r56 > linux-evl: v6.12.67-evl2-rebase > > I traced the issue already trough the following code: > net/core/net_namespace.c:355 > kernel/evl/net/net.c:35 > kernel/evl/net/ipv4/ipv4.c:41 > kernel/evl/net/ipv4/arp.c:323 > > However, I lack the knowledge to do a proper fix. One way would be to just check in evl_net_init_arp() if it is already > registered and don't do it more than once but that doesn't feel right. It looks like the system is instantiating multiple network namespaces, for each of which we set up an ARP front cache by calling evl_net_init_arp(). Bad idea to hook a system-wide handler there as well. Could you confirm this fix [1] works for you? Thanks for reporting this. [1] https://gitlab.com/Xenomai/xenomai4/linux-evl/-/commit/569beef061321c2c00d775b13ad0aec1a1d2a416 -- Philippe.