From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B9E682F39D7 for ; Thu, 18 Sep 2025 21:10:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758229825; cv=none; b=C+cFYkRfHue9K4TCHL+3wbw4RKaR1eybusKbBj3jXSEPvsmv5BPMH+oiBwUGB6TTIs1a3ooKoSG8P1AH3tHLTidM++GOAxyVW6/xONssf1e7pxqGyEjAjAElHzLfYu3h3wnRwaEvDwr5lOpST8M5/31Ywq6WMHwTw0S9zN2cJz8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758229825; c=relaxed/simple; bh=jKkcmf3MDfbgYuwWGn6u6Q37sQo63v9wUZb8rTdwbcQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=lE9W1qoQ9wHDQaXp1ly2FNcssbvrF8xNFy1B9q6rx3IaVtQ3NKYQq6pU5X8xQurpO9kugVVHtK7mSB7ZFVno3XdSBLL+yXc9oalzkBMTH90tx+NSvme74EHdtvZw6NODjlssoMrBKKWMgZbgCKQ+suCrXW/XTjnBhEH2T7TKH+k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=kdoP1WsY; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="kdoP1WsY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6A8B7C4CEE7; Thu, 18 Sep 2025 21:10:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758229825; bh=jKkcmf3MDfbgYuwWGn6u6Q37sQo63v9wUZb8rTdwbcQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kdoP1WsYZzMmLUBAA/L36XxB9IEcVc4Z3/ChXrxWDhNsJZJzU3SIc6TS2LkVInryU tVochwRrdRZdIIdxdorpyqRVl+mGLXr55YDmTdu95nHE/JWnwHuxD+/fVTdWmvhm2i 6LDGQnf6YW+KYWmnCOFrMmX3GvFaPoTYiFMkhDRmYJ5Ozf+V44WmhS24veu9DGogg7 UK14SwgRtDoiHI8l/XXxGjxXg/JvpNDz6zCXDE5S/s93DO+Sw0bsAbP/nSEjlkwS/+ Ccmvj9xhlgLfoch+tRE/ZqhgwmP39qNFB/c2K8tAJB5QkzUaekiVd5CNy9Gldhfi92 qsolnw97+XVpg== From: Will Deacon To: catalin.marinas@arm.com, ryan.roberts@arm.com, akpm@linux-foundation.org, david@redhat.com, lorenzo.stoakes@oracle.com, ardb@kernel.org, dev.jain@arm.com, scott@os.amperecomputing.com, cl@gentwo.org, Yang Shi Cc: kernel-team@android.com, Will Deacon , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v8 0/5] arm64: support FEAT_BBM level 2 and large block mapping when rodata=full Date: Thu, 18 Sep 2025 22:10:08 +0100 Message-Id: <175822779944.710258.10028837182267037801.b4-ty@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250917190323.3828347-1-yang@os.amperecomputing.com> References: <20250917190323.3828347-1-yang@os.amperecomputing.com> 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-Transfer-Encoding: 8bit On Wed, 17 Sep 2025 12:02:06 -0700, Yang Shi wrote: > On systems with BBML2_NOABORT support, it causes the linear map to be mapped > with large blocks, even when rodata=full, and leads to some nice performance > improvements. > > Ryan tested v7 on an AmpereOne system (a VM with 12G RAM) in all 3 possible > modes by hacking the BBML2 feature detection code: > > [...] Applied patches 1 and 3 to arm64 (for-next/mm), thanks! [1/5] arm64: Enable permission change on arm64 kernel block mappings https://git.kernel.org/arm64/c/a660194dd101 [3/5] arm64: mm: support large block mapping when rodata=full https://git.kernel.org/arm64/c/a166563e7ec3 I also picked up the BBML allow-list addition (second patch) on for-next/cpufeature. The fourth patch ("arm64: mm: split linear mapping if BBML2 unsupported on secondary CPUs") has some really horrible conflicts. These are partly due to some of the type cleanups on for-next/mm but I think mainly due to Kevin's kpti rework that landed after -rc1. So I think the best bet might be to leave that one for next time, if that's ok? Cheers, -- Will https://fixes.arm64.dev https://next.arm64.dev https://will.arm64.dev