From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx.nabladev.com (mx.nabladev.com [178.251.229.89]) (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 D9B0F30AAB8 for ; Tue, 4 Nov 2025 07:53:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.251.229.89 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762242823; cv=none; b=fpx3hzErXNVIZL2JRQQqAQaOql5sFYZVJEl1vp2QHEz7Y4z5zGEuwtDsbR+L1D6Jf7rrWYHbo9Yt4AfUH2KdFvj/K5kpeZ53ZdYrmHRyk/LMxsr3OOJZWHfCpuixFZpvOHf3YoQSbyEhQzms2QrGVbzRopy76JuWh7OhEwGUtyI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762242823; c=relaxed/simple; bh=6Mzgy5aDjQBqykbLcSJ3a3sixKIXmq1QB7Un+o/s5io=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=euFkuQNEQFo8BReFH5FchBQGDNdeMe1Il+6JjHGkmAWqd63LLkROwru5bXmb5jhTVPGMbylcKNoivQSFf7QEUg3YDRdgKN2njOH1jKmtRKBJKJL8VxvcdWb3Ao24WqqA83aqbYREYzF0arO1Wc59CR9GlT8vJerxQVbkXLG6fu4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nabladev.com; spf=pass smtp.mailfrom=nabladev.com; dkim=pass (2048-bit key) header.d=nabladev.com header.i=@nabladev.com header.b=UMoWd0ou; arc=none smtp.client-ip=178.251.229.89 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nabladev.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=nabladev.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=nabladev.com header.i=@nabladev.com header.b="UMoWd0ou" Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id C2F3D108D02; Tue, 4 Nov 2025 08:53:31 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nabladev.com; s=dkim; t=1762242812; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=jweSj5czry2AuxzblM4G/p0/TGfpEODQ71wh2f5EC78=; b=UMoWd0ouBGaVJNbiy/rMUUa5yPxyS70h7QpAAXvj4VcYxa55y6rxFprm1n8UYaLsIgWIwV R4LpPd9y3fBDLpyzifETIgxh3hCd0ncpDMubNKp0sznMRH1aWNaTAPTU/1Cq0wlGT6v0kh Zz0cxJafaw4CbVNMZnojL9iB3MGFFVOQ7Yv+HmeDVUpdR5zy/MugKtpp5BN9AbFGnLLNOu PqPPx5/GEF2MIuobyccUcnKL8bRv8UWOuzXMEIfFVZ4GTvftYkBBw6B7ZkBl8oh1ACjawr gPeJR5gRWr2kQMr7gIbyG1JYc32xBapqys+0Lf3Uzh5hPhMmr9e7U0iiJdJG2w== Date: Tue, 4 Nov 2025 08:53:29 +0100 From: =?UTF-8?B?xYF1a2Fzeg==?= Majewski To: Philippe Gerum Cc: Giulio Moro , Xenomai Subject: Re: Unexpected switches to in-band Message-ID: <20251104085329.3bfa97f9@wsk> In-Reply-To: <87cy5znrc1.fsf@xenomai.org> References: <20251009151737.0d03b211@wsk> <20676160-4572-d92d-4b33-ff4255946345@bela.io> <87qzv9sa9c.fsf@xenomai.org> <87ikgls9kh.fsf@xenomai.org> <20251020094705.2ac256f2@wsk> <9d2bacac-8d70-f083-e926-21beee2207c2@bela.io> <87o6q1ad07.fsf@xenomai.org> <20251023155439.0170f987@wsk> <87a51djuor.fsf@xenomai.org> <20251027120535.7933c720@wsk> <20251027172505.29eecfb2@wsk> <875xbyawx7.fsf@xenomai.org> <20251029145125.71debaab@wsk> <20251030132602.2d1ccfcc@wsk> <87qzukuzy5.fsf@xenomai.org> <20251031165615.2c9f72f5@wsk> <87bjlnc9u5.fsf@xenomai.org> <20251101165957.12432bf4@wsk> <58fcd922-3a50-74c5-bfee-01cbcb7e1e6d@bela.io> <87cy5znrc1.fsf@xenomai.org> Organization: Nabla X-Mailer: Claws Mail 3.19.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: xenomai@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Last-TLS-Session-Version: TLSv1.3 Hi Philippe, > Giulio Moro writes: > > > Hi everyone, > > > >> CONFIG_COMPACTION=n - it also automatically set CONFIG_MIGRATION=n > >> From the Kconfig dependencies CONFIG_MIGRATION=n -> !PREEMPT_RT > >> [=n] > >> (i.e. it can be only enabled when PREEMPT_RT is NOT) > >> I've just set CONFIG_COMPACTION=n (which also disabled the > >> CONFIG_MIGRATION) and now I cannot reproduce the issue on my setup > >> (i.e. v6.6.) anymore. > >> It looks like those (enabled by default) config options have > >> slipped in > >> silently and introduced the issue... > >> > > > > I can confirm disabling CONFIG_COMPACTION and CONFIG_MIGRATION > > fixed the issue for me as well. Fun fact is that I started looking > > over these options when I first raised the issue, but then realised > > that evl check did not flag them as problematic, giving me a false > > sense of security ... Without knowing much about the internals, in > > hindsight it makes perfect sense that the process was more likely > > to fail early on in the lifteime of the process and/or of the > > kernel than after it had been running for a long time: once the > > memory layout has settled, it's unlikely it will get moved again. > > > > By the way, I was thinking that replacing an in-menuconfig warning > > (a la Xenomai-3) would be nice to have, instead of having to > > manually run evl check on the config file. > > Actually, we want both. Some automated configuration process may not > give us any hint loud enough, a runtime check is always welcome, > especially when providing support. > IMHO, it would be enough if we would have: 1. evl check complaining loudly about CONFIG_COMPACTION=y and CONFIG_MIGRATION=y 2. Just adjust Kconfig to have: CONFIG_MIGRATION if !DOVETAIL -- Best regards, Lukasz Majewski -- Nabla Software Engineering GmbH HRB 40522 Augsburg Phone: +49 821 45592596 E-Mail: office@nabladev.com Geschftsfhrer : Stefano Babic