From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Arnd Bergmann" Subject: Re: [RFC PATCH] asm-generic: Unify uapi bitsperlong.h Date: Thu, 08 Jun 2023 14:56:30 +0200 Message-ID: References: <1683615903-10862-1-git-send-email-yangtiezhu@loongson.cn> <76d3be65-91df-7969-5303-38231a7df926@loongson.cn> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Subject:Cc:To:From:Date:References: In-Reply-To:Message-Id:Mime-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=fAMs3yk928e0XL82hJL+yjT6GZJAWgX2li/iUe6RkWI=; b=AETYDdfAkpnpmd exhbaKTQu9R+JQWsrby5RNAkyNB8pgNzj+LE8ybl/zl15hYnSgUMLRkprKdcoZzpAGc+NLtr6/St3 uj94wMKumVpAXICGS80dUmNqDobR9UJmrYioG0DCZJoFLSof4ekMZkIF34olsvgC1FN+QPG6k1Kk0 e12sxzD6qV6AmtBxLQg9zpgFxXsJCuYQSxDeYiQCamc57eJbAXgqUS2t2hYyy3tJcLs8rm5k8k08p 2Kb+T/bs3n7y1S2/0geGY4ATSEb7dKLlREgvi0EXV8AWQhpSfk9rVV0gClBZR1FvT+kfDWR/96000 Ulwkl45dLWTmFgOncVqQ==; 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== In-Reply-To: <76d3be65-91df-7969-5303-38231a7df926@loongson.cn> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+glpr-linux-riscv=m.gmane-mx.org@lists.infradead.org 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 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