From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2D841C7EE23 for ; Thu, 8 Jun 2023 12:57:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236180AbjFHM5G (ORCPT ); Thu, 8 Jun 2023 08:57:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39656 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233162AbjFHM5E (ORCPT ); Thu, 8 Jun 2023 08:57:04 -0400 Received: from wout4-smtp.messagingengine.com (wout4-smtp.messagingengine.com [64.147.123.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5DDC52727; Thu, 8 Jun 2023 05:56:54 -0700 (PDT) Received: from compute6.internal (compute6.nyi.internal [10.202.2.47]) by mailout.west.internal (Postfix) with ESMTP id 54C02320090B; Thu, 8 Jun 2023 08:56:52 -0400 (EDT) Received: from imap51 ([10.202.2.101]) by compute6.internal (MEProxy); Thu, 08 Jun 2023 08:56:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arndb.de; h=cc :cc:content-type:content-type:date:date:from:from:in-reply-to :in-reply-to:message-id:mime-version:references:reply-to:sender :subject:subject:to:to; s=fm1; t=1686229011; x=1686315411; bh=87 pYxZKtAnGH9oKy6pFHT1xHGz/WCvjygA8bIAeiKlA=; b=ZeX8L7pUZ5UIpOMY9M 9g1j8HgG7+kWRpcbfg5uyET+fH7MKKs1mmJd5GiTBtyG3e4Kb2S8oySTp2FMKVD5 6cPeO3EdjyqNf0z8ONTk7Y4xvff+IrOd/IEXcnucUJGHtunt79pl/8nMv5FddrAG uQycTyVPowhwXFFmqqICRAUW8Rc8su6sZcA/n9xK4gkWZLq4FLGKG2+b/ofZFCuf AMrvTTYFhxmA+huvu4Cjp75ap2Sf7MJK9JQ3pOVGdml0Q2jBbC5ggWY9QzN5MNkV 6Cu7hWpbrBfBHGI32iWeZ+txnWuzY/rdQ0nguYoFIEmTdH+KuW0pvhtt0TNXW/yQ JP2A== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:content-type:date:date :feedback-id:feedback-id:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:sender:subject :subject:to:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm1; t=1686229011; x=1686315411; bh=87pYxZKtAnGH9 oKy6pFHT1xHGz/WCvjygA8bIAeiKlA=; b=U6XRVjfP+EHUDQvBv8cPL9pD/KGwo iw0KnKWmDepSUXHsue7XYEEv3jSKmc5VneLRFAnbB7bjvWnjZAFimwr1xI3aZ2r2 RdXIfnuvROK2EFMWjCfwC3PBH93ikfGkGtdqsK5mas70L80DoSDFO8TKCaTh4eHz K+ZspG/2pADrn/0PYTVFOIEgwbfucSZzMW91caxx97W+pzHbK9rkgf+0+vkf4oDD jH5hLErq64lWlh17sXL7u3Td79LGnkb4UvXKtQw37hle5MqhD6Sfrp8G6cLyNfqi QTut/2emZSYLnRuBAzk7rDPI0a305yR06UG65WJAnPVfPk2TBPYkBuvMA== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvhedrgedtiedgheekucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepofgfggfkjghffffhvfevufgtsehttdertderredtnecuhfhrohhmpedftehr nhguuceuvghrghhmrghnnhdfuceorghrnhgusegrrhhnuggsrdguvgeqnecuggftrfgrth htvghrnhepkeehtefguddvleejvdeileeifffhueevgedvheeiudfhueevgfehkeeitedu keeknecuffhomhgrihhnpehsohhurhgtvgifrghrvgdrohhrghenucevlhhushhtvghruf hiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpegrrhhnugesrghrnhgusgdruggv X-ME-Proxy: Feedback-ID: i56a14606:Fastmail Received: by mailuser.nyi.internal (Postfix, from userid 501) id 9B111B60086; Thu, 8 Jun 2023 08:56:50 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface User-Agent: Cyrus-JMAP/3.9.0-alpha0-447-ge2460e13b3-fm-20230525.001-ge2460e13 Mime-Version: 1.0 Message-Id: In-Reply-To: <76d3be65-91df-7969-5303-38231a7df926@loongson.cn> References: <1683615903-10862-1-git-send-email-yangtiezhu@loongson.cn> <76d3be65-91df-7969-5303-38231a7df926@loongson.cn> Date: Thu, 08 Jun 2023 14:56:30 +0200 From: "Arnd Bergmann" To: "Tiezhu Yang" Cc: Linux-Arch , linux-s390@vger.kernel.org, llvm@lists.linux.dev, linux-ia64@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-parisc@vger.kernel.org, x86@kernel.org, linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, loongarch@lists.linux.dev, linux-alpha@vger.kernel.org, sparclinux@vger.kernel.org, linux-riscv@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, bpf@vger.kernel.org, linux-arm-kernel@lists.infradead.org, loongson-kernel@lists.loongnix.cn Subject: Re: [RFC PATCH] asm-generic: Unify uapi bitsperlong.h Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org On Thu, Jun 8, 2023, at 09:04, Tiezhu Yang wrote: > On 05/09/2023 05:37 PM, Arnd Bergmann wrote: >> On Tue, May 9, 2023, at 09:05, Tiezhu Yang wrote: >> >> I think we are completely safe on the architectures that were >> added since the linux-3.x days (arm64, riscv, csky, openrisc, >> loongarch, nios2, and hexagon), but for the older ones there >> is a regression risk. Especially on targets that are not that >> actively maintained (sparc, alpha, ia64, sh, ...) there is >> a good chance that users are stuck on ancient toolchains. >> It's probably also a safe assumption that anyone with an older >> libc version won't be using the latest kernel headers, so >> I think we can still do this across architectures if both >> glibc and musl already require a compiler that is new enough, >> or alternatively if we know that the kernel headers require >> a new compiler for other reasons and nobody has complained. >> >> For glibc, it looks the minimum compiler version was raised >> from gcc-5 to gcc-8 four years ago, so we should be fine. >> >> In musl, the documentation states that at least gcc-3.4 or >> clang-3.2 are required, which probably predate the >> __SIZEOF_LONG__ macro. On the other hand, musl was only >> released in 2011, and building musl itself explicitly >> does not require kernel uapi headers, so this may not >> be too critical. >> >> There is also uClibc, but I could not find any minimum >> supported compiler version for that. Most commonly, this >> one is used for cross-build environments, so it's also >> less likely to have libc/gcc/headers being wildly out of >> sync. Not sure. >> >> Arnd >> >> [1] https://sourceware.org/pipermail/libc-alpha/2019-January/101010.html >> > > Thanks Arnd for the detailed reply. > Any more comments? What should I do in the next step? I think the summary is "it's probably fine", but I don't know for sure, and it may not be worth the benefit. Maybe you can prepare a v2 that only does this for the newer architectures I mentioned above, with and an explanation and link to my above reply in the file comments? Arnd