From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 0779C3B19B2; Wed, 26 Aug 2026 07:32:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787729565; cv=none; b=AAqjCOteq2u02e9rRz8D+cnF8rtk4v8UTr0UEefNa0xTR1bWPnffvsYCFKpVVlvUSITWqrZZt+9RPxZXNDTOv3nfWoAUqTCqwOYA5Emgc9NE1SAyYhwthdZhsMZtd5w9uDI6EvhJldMDUfha7iojumeoQoioCQSwMRmDenzL5z8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787729565; c=relaxed/simple; bh=44bsU91JLgcVuaZAxI42z3R4oe6aaUU0l1OSN9XNqIU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=lr8ZAtSue6jiYgIvpuMUGm3I4uteMbrjrqwEh/noFEIjz6BwX7btM6Cp2KVj7ALTr3UEciu0Yt6IgPWA5TIWHtcsohUMhZc0PDE+ZQG3YpC52KX4XITUjhxqrPAvThfCc4l42dp6M8M96SMtnCmlWwfqOO9SOireAAOv6ReJtxM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=VMQGacdc; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=z2MdUAMa; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="VMQGacdc"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="z2MdUAMa" Date: Wed, 26 Aug 2026 09:32:33 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1787729555; 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=v0qYw6dI/lOMP/K9P716HVlCet1n8A6GD/0q9HLVzrs=; b=VMQGacdcvMuc2msrSxPg8sy3s578U8lucEvh/cZE4V/kuiAr7MmALRl2ClMviXBxGNm52k DbiAwAFtpBiS4r3m3/8x0wfzKkcxmLnRbHqy2n/cBIG430HZhfYOX7I4F1BCgRQ1KPQKgl 1iUepfgOJ9GiAGAOEDW3L01Ncp2uMFz/i9BWDfUuLNvR1nhKtFS1iI25NZVTck5Dwj5q6q 8KosOZZD7dw+zVRg/8noxbbDhR8wEdzdU4bGFERhcMcIEAMuvENanuTyijfYqGjTNnsK9r TzT8azEkht+nlDD3AQN2+zNGXHPocQGutv2HAv/yecSdl7SWLMdzlhhdv2f8QA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1787729555; 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=v0qYw6dI/lOMP/K9P716HVlCet1n8A6GD/0q9HLVzrs=; b=z2MdUAMaarXzYXJUnZ9mDq2Oq8fo1ufaKMNgfCTuwIciKR+qIP2KDHfk5DiFU/9/pyr2Ng e/k7E2VBHGxqtJBQ== From: Sebastian Andrzej Siewior To: "Paul E. McKenney" Cc: Sean Christopherson , David Woodhouse , Jason Gunthorpe , Michal Hocko , Steven Rostedt , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Clark Williams , Simona Vetter , Jerome Glisse , Christian Koenig , Paolo Bonzini , linux-mm@kvack.org, kvm@vger.kernel.org, linux-rt-devel@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/mmu_notifier: Remove non_block_start/end() from notifier invocation Message-ID: <20260826073233.T-KtFXmj@linutronix.de> References: <333c4cdb-8f34-4e3f-a47f-961f47e089a0@paulmck-laptop> <11dcf5a87125451897982f728c1f65a5151987e4.camel@infradead.org> <69567965-48fd-48c5-abb6-0699d7f5bd16@paulmck-laptop> <124af87fb49c267eeb26b8b4d952b9b1a5b3fb68.camel@infradead.org> <9427a8e0-3ba6-4f31-a35d-54429bd7e071@paulmck-laptop> <3d0463b6099d4fcde9a025a2f9e231d75303b61c.camel@infradead.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable In-Reply-To: On 2026-08-25 13:51:14 [-0700], Paul E. McKenney wrote: > Very good, preemption disabling it is! It is quite possible that the > PREEMPT_RT guys will need something else, but one thing at a time. This reminds me of classic RCU ;) It might work in this use case but I am afraid that other users might come along where it actually hurts. With PREEMPT LAZY the preemption within the read-section should hopefully be the exception. =E2=80=A6 > Thanx, Paul Sebastian