From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 4E4822931CD for ; Tue, 1 Sep 2026 11:14:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788261281; cv=none; b=ckp9pC5QClbdGqxUNvUO4fQibpzJB0CQntRMMnlpENddRMm1Go+LXX9MSIKUoDm5dNpMBalUp8LlsJqP2H9NOROVrOweeW7zh0JBPvsfKAsdjHUvPRl/755xhSn1gFLSqW3o9YRTYJNqOftRpXzL0gzZHQt+uRpigY5rlk2Pld0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788261281; c=relaxed/simple; bh=DFhdRtlpNvH0Vp/3IZNUnu/1thAgh0mVLj5efxG+LCo=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=TF7f6Aobg1yq9KtP9No5yKDqqfC+g1OGFQTG9nYBzDvtVGLVCzHCx5VQuislV8p7EmZfiU7h1NgXwBOHVUD1wtYcZQ2P4nviq9jto80xQvQV7oZN0r5v5vOYE2PTApkRZpBaD5QPgk2QU5rn4G7Ei3Jz3Avk3K6ypybZR7Pgc4s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GJ1cx9OI; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="GJ1cx9OI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D6B9C1F000E9; Tue, 1 Sep 2026 11:14:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788261280; bh=DFhdRtlpNvH0Vp/3IZNUnu/1thAgh0mVLj5efxG+LCo=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=GJ1cx9OIc7wB8CR7kJv5coNUG7MyZZKmZMM7F7SxOLpLZ0h7YIMnc2mhhdBF2HwUO GRf3zHvvX/JUkCPwWjJA8GQ3KbOR+5FZHTP9MdhAZHaUqLAyz885MkvkXyN6CH1NS2 MN8PphegXntdbF4YPA5PqWg4vR0YKPUd37BbFHCIcdzD25TAdAXsbvMqIriw2KRp4y A82Of6ObCISgbmZlWVCGHq8xs0QCNSXLs5gaXy7ClIJVpUBU1dz0hVBoOw/C77JlNw by5PYqhg6bQH8mL5aLwkg/SWCIGMDRkNMsLDJ3F+g04F1qsuUQzbc/QwwZxUhmgyA2 k+UQaPNtHZoIA== From: sashiko-bot@kernel.org Subject: Re: [PATCH 03/12] mm: enable MMU_GATHER_RCU_TABLE_FREE for MMU riscv Reply-To: sashiko-reviews@lists.linux.dev To: =?utf-8?b?TG9yZW56byBTdG9ha2VzIChBUk0p?= Cc: "Alexander Gordeev" , linux-s390@vger.kernel.org, "Christian Borntraeger" , "Vasily Gorbik" , "Heiko Carstens" In-Reply-To: <20260901-rcu-pagetable-freeing-v1-3-5456a81c8212@kernel.org> References: <20260901-rcu-pagetable-freeing-v1-0-5456a81c8212@kernel.org> <20260901-rcu-pagetable-freeing-v1-3-5456a81c8212@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 01 Sep 2026 11:14:39 +0000 Message-Id: <20260901111439.D6B9C1F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > Currently riscv gates MMU_GATHER_RCU_TABLE_FREE on CONFIG_SMP and > CONFIG_MMU. >=20 > Commit 69be3fb111e7 ("riscv: enable MMU_GATHER_RCU_TABLE_FREE for SMP && > MMU") enabled CONFIG_MMU_GATHER_RCU_TABLE_FREE for CONFIG_SMP, CONFIG_MMU > riscv builds. >=20 > This is expressly for the safety of GUP-fast walkers (CONFIG_HAVE_GUP_FAST > is enabled if CONFIG_MMU is enabled). >=20 > Naturally a single core system does not encounter issues with software pa= ge > table walkers being correctly synchronised across cores, as there is only= a > single core. >=20 > However, CONFIG_PREEMPT_RCU is still available on a riscv UP system, so f= or > a future RCU-only page table walker, this guarantee is required to prevent > concurrent page table teardown. >=20 > All page table freeing is already done via tlb_remove_ptdesc() so the > conditions of CONFIG_MMU_GATHER_RCU_TABLE_FREE are already met. >=20 > This forms part of an overall effort to switch every architecture to this > mode. >=20 > Signed-off-by: Lorenzo Stoakes (ARM) Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260901-rcu-pageta= ble-freeing-v1-0-5456a81c8212@kernel.org?part=3D3