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 D8CF22BEFF6 for ; Mon, 20 Oct 2025 07:47:19 +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=1760946442; cv=none; b=YuE0+d0C4Fw9Vqm07ZCapFChB8v02WotwSQ+CitSup93eXBhxxnnZ/I3WEcyBLykA2NG3J8PKRGWN/dvc3h0FqFl/qjfi7iCzX7efKNfQnJDj0szkJTdwogiO35U43Uz1gNyAT9JO24tfPdw6M2xF5ZKXHr/BLLNT9A96pGCGzk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760946442; c=relaxed/simple; bh=8YojIFxQUmS+KAC5DXYuLOU4aiJAww9xcqI3QF6znzk=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Vwme6iZT6COi4ehv7WiTXMJV+6/PSpzBwWcXngapPPjjDd48R7yjVKyVnoCThfoQZFiEUQinFBFaI3BLc1HL5q9HVdUNz3rDXYhchSoDan86jtxbKPPQlJR4fIyrZ2ayBoRYbhn9ua08SswEsxIPbWtvq+BleWdXkhLjRYdI3no= 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=EiMEJlxi; 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="EiMEJlxi" Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 676011087C3; Mon, 20 Oct 2025 09:47:07 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nabladev.com; s=dkim; t=1760946427; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=yrHXRFy909em5tveFa/KAiL/BtFxLP8QnxsaGpqCt4U=; b=EiMEJlxiX7FKrdgQ95+varGke0BscNiAyYPotoEDStX0P2cg8z6jW8EfvGDwESXGf2+k1n eFiH4QGaRdRQdvfOms8QyGkvDaHTEA4/lvTcgRU5LXH/3ud8dXLmpEeoE81JBfFMhRcGtt BVWsoHBcIK031/Cbfs9AJP+S8edJB3t3mQ7f18r9NZ+MDbLKbY2mj5F4E5zANjwG0MputQ kFjkCQLDGDiv8QBVKfJOZliY00fpR4dU5fzTvcy65Qnqjfj6LEG4rfBBv6DN9xwQCOUaS4 76G2rdLJT/Q0CXOTRaiAOdrGElLsX4pGoeDY2c1anJEzhVe2mUd/KK7wISkDzA== Date: Mon, 20 Oct 2025 09:47:05 +0200 From: =?UTF-8?B?xYF1a2Fzeg==?= Majewski To: Giulio Moro Cc: Philippe Gerum , Xenomai Subject: Re: Unexpected switches to in-band Message-ID: <20251020094705.2ac256f2@wsk> In-Reply-To: References: <20251009151737.0d03b211@wsk> <20676160-4572-d92d-4b33-ff4255946345@bela.io> <87qzv9sa9c.fsf@xenomai.org> <87ikgls9kh.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 Giulio, > I realised that gitlab's v6.12.y-evl-rebase and v6.1.y-cip-evl-rebase > can boot as-is on the PocketBeagle 2 and so I'll keep using those for > tests going forward, without any third-party patches. > > >> Ok, so it looks like both of you observe the same issue, which > >> seems to be arch-independent. Checking the code which takes care > >> of preventing COW for oob-enabled processes (a behavior which may > >> cause unwanted minor faults in a tricky way), I stumbled upon a > >> really bad bug. Could you check whether the patch below helps? > >> > >> diff --git a/include/linux/sched/coredump.h > >> b/include/linux/sched/coredump.h index 73de18353e79..c6b1efcbd833 > >> 100644 --- a/include/linux/sched/coredump.h > >> +++ b/include/linux/sched/coredump.h > >> @@ -91,7 +91,7 @@ static inline int get_dumpable(struct mm_struct > >> *mm) > >> #define MMF_VM_MERGE_ANY 30 > >> #define MMF_VM_MERGE_ANY_MASK (1 << MMF_VM_MERGE_ANY) > >> -#define MMF_DOVETAILED 31 /* mm belongs to > >> a dovetailed process */ +#define MMF_DOVETAILED > >> 18 /* mm belongs to a dovetailed process */ > >> #define MMF_TOPDOWN 31 /* mm searches top > >> down by default */ #define MMF_TOPDOWN_MASK (1 << > >> MMF_TOPDOWN) > > Tried that on top of v6.12.y-evl-rebase , it doesn't seem to fix the > problem, neither for latmus nor for our application. > > > Note: this issue only affects kernels from v6.10 and on > > I can confirm that on v6.1.y-cip-evl-rebase I don't see that issue, > even though MMF_DOVETAILED is 31 also there. Could you share which version of libevl do you use? -- Best regards, Lukasz Majewski -- Nabla Software Engineering GmbH HRB 40522 Augsburg Phone: +49 821 45592596 E-Mail: office@nabladev.com Geschftsfhrer : Stefano Babic