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 E523F4483AC for ; Fri, 25 Sep 2026 20:19:49 +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=1790367592; cv=none; b=O1LcC6SDanGj3U60yQAastg1muHywd2AC4TEuTgnhyyZBNKX92bIlEw9p7J8kaFPRgM42W+B7IVky+Bk4qhn0GGPG8/pVZ4MICsALKPrQUJgJ1hh1kqfPEW1oC9jJTJPe16cBwn6jhj3nYKBRn003HeT97OKTQluEWXQCUPssoQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790367592; c=relaxed/simple; bh=DB7l3UbPGe2ta64+GYQBTKDNGJNIRwr3QlZS5qwlLaE=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=ut6sTGGPj/iVpjAK65rMrNYeC2RxIDSyVLKkSQ7xP5BdEJrc1TTkUyIQbWH1a10qZ8Gd+K49HY8I00xncXSf2SFXTeE5nsQcQuz0W3minHyFSypm6kqhPTqwUkB86zUJ/2I1JsugsiXqTY6BBgOt15tltGym/jL0t8HRO9DQxVw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EE4MREHN; 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="EE4MREHN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 46E921F000FF; Fri, 25 Sep 2026 20:19:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790367587; bh=DB7l3UbPGe2ta64+GYQBTKDNGJNIRwr3QlZS5qwlLaE=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=EE4MREHNbGWC4eFHpFUPV+sVlj9a7uCdjbjfRcLeoQa6z5NLGZDkGL0F0a/5ME8jA jrExlQ9CWbBdVMRiq5o8zzQN48Q4/i1sBhigmWYPBrJX6UGPBifWz8jjkqbb6W4c57 umITQ0okZmxVfkuRxk/cX0+rvUjEM1+VMUR6RedFmEu/kqp2LiI2oCi1P+cvbMbu26 dqY+tbSetXNsBHeKo+t0bM+grCD/tXbx2HB05ePrbJWv6cJJgktzcQZr4uoR6xj4bN tvpDlw4LvtxJVJ02OgP0zL08RHsX80Vp5RnL4Kq3wBiRmNA7Z80glBKTelAnh29gs4 xhRtf/n6ZEDEw== From: sashiko-bot@kernel.org Subject: Re: [PATCH v5 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: linux-s390@vger.kernel.org, "Heiko Carstens" , "Christian Borntraeger" , "Alexander Gordeev" , "Vasily Gorbik" In-Reply-To: <20260925-rcu-pagetable-freeing-v5-3-31e91065fea4@kernel.org> References: <20260925-rcu-pagetable-freeing-v5-0-31e91065fea4@kernel.org> <20260925-rcu-pagetable-freeing-v5-3-31e91065fea4@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 25 Sep 2026 20:19:46 +0000 Message-Id: <20260925201947.46E921F000FF@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) > Acked-by: Lance Yang > Tested-by: Lance Yang > 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/20260925-rcu-pageta= ble-freeing-v5-0-31e91065fea4@kernel.org?part=3D3