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 A01794519BE for ; Fri, 11 Sep 2026 19:49:32 +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=1789156186; cv=none; b=KMK4SYG87kPEwLCr7DFRpxo1F70AiMbK9YriKGJIOIyKozDE54ZejSz9fLNxY0YBC/YpvX/IOzlxIA4YP77c8gklBFLWZ6huh42nGiQxtqoi480B5jD9u8sXAm7sG3AP7TCbz32xI0nbmO6or9Tj4rjfF8dWx//9xP1WHyvSGYA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156186; c=relaxed/simple; bh=RKeFB0A+kImQ7nOuZ968V5ZQk/GSvwUrWVw9u3OlwiM=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=q5/uJscMcwRlMDvu/G8BRLwd2y28TipfomRUnzzCF/+WlhSMQhp/FOhXFKE/if5wTEUsLZxw7en1aXnsqJ4sZJf9+d1p0OesWYXmtSpVy1sCBQON/kJVTZSBSs6zuW3eOu8Ld91gnYNTKFUcFN8f77i1GDLiBFIqYKPe2otcVJw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Z/yBMkLb; 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="Z/yBMkLb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 145071F0089B; Fri, 11 Sep 2026 19:49:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789156169; bh=RKeFB0A+kImQ7nOuZ968V5ZQk/GSvwUrWVw9u3OlwiM=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=Z/yBMkLbOtC3vvAdXk2BBNpIsvh5KlgqWXFJfh6s+TVHXo0igOs+kZPeKGeA8cQ75 KT0bMgycf69x8kmg1oAJZl+UTDOUd7KJqQsMq1oNux0uGzQKddaLuo40ePOy5fjJWP +fmXrETqnX/GkhfbQyd8TsNzavkkmjssSlQ1z1Tn9lPbyevvxF30gaoerssDTQI7ra oFl3+dC+oFc84GsBecWhiqUglRZWmmIpVFAyS8bwE5NHrIMVe5PHK7JBH7hSqwwQ1V IrTMRpvOy6y3UcCLfa9Jo793X1/tSvoNnJs+a2Pqsuz0uMpVfPRLp3IgG526OmZhxH tyzvzdsD8fioA== From: sashiko-bot@kernel.org Subject: Re: [PATCH v3 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: "Christian Borntraeger" , "Heiko Carstens" , "Vasily Gorbik" , linux-s390@vger.kernel.org, "Alexander Gordeev" In-Reply-To: <20260911-rcu-pagetable-freeing-v3-3-7b8c86103821@kernel.org> References: <20260911-rcu-pagetable-freeing-v3-0-7b8c86103821@kernel.org> <20260911-rcu-pagetable-freeing-v3-3-7b8c86103821@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 11 Sep 2026 19:49:28 +0000 Message-Id: <20260911194929.145071F0089B@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 > Acked-by: Kiryl Shutsemau (Meta) > 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/20260911-rcu-pageta= ble-freeing-v3-0-7b8c86103821@kernel.org?part=3D3