From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from angie.orcam.me.uk (angie.orcam.me.uk [78.133.224.34]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 1D7222773E5; Mon, 13 Apr 2026 05:47:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=78.133.224.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776059269; cv=none; b=QeSSnTQ5WCx2Uj3fQdKD5vClqnMl+kAXwHmoQSJ7Xs9dksD57pMKsWjzf8ew395QnU6gG7A8xHfQ/5HRlSo+Ooelzk2PAceFZkBb0WVjZnWcwVm+2JFeL9NF5PCSnBjDXXtyzGERfi8IpNVFQRf0vUsE4RLqWnt795LtRmapbk8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776059269; c=relaxed/simple; bh=YxepDZzylg7DLxJ1UuKV5wvO8y/p14MplYX7PzmcQ08=; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References: MIME-Version:Content-Type; b=MWbOo9tARfrBcn9eCmjchtLcu1r1J5lRuBc0zX4vTTkBRHjrM005QWIXYzagKgVmbOA1+vcY/1KRpr+8fALLgx5V8fd5yZ9xvRcO92MT2JFxDdxJKKXegRxQ3RbBl/dgtmtyV2UHqPH0cPMUsH8IqkMp1AyutpAbh+2ZqvUfQSs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=orcam.me.uk; spf=none smtp.mailfrom=orcam.me.uk; arc=none smtp.client-ip=78.133.224.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=orcam.me.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=orcam.me.uk Received: by angie.orcam.me.uk (Postfix, from userid 500) id 2FA4892009C; Mon, 13 Apr 2026 07:47:45 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by angie.orcam.me.uk (Postfix) with ESMTP id 283D292009B; Mon, 13 Apr 2026 06:47:45 +0100 (BST) Date: Mon, 13 Apr 2026 06:47:45 +0100 (BST) From: "Maciej W. Rozycki" To: Thomas Gleixner cc: LKML , Arnd Bergmann , x86@kernel.org, Lu Baolu , iommu@lists.linux.dev, Michael Grzeschik , netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Herbert Xu , linux-crypto@vger.kernel.org, Vlastimil Babka , linux-mm@kvack.org, David Woodhouse , Bernie Thompson , linux-fbdev@vger.kernel.org, Theodore Tso , linux-ext4@vger.kernel.org, Andrew Morton , Uladzislau Rezki , Marco Elver , Dmitry Vyukov , kasan-dev@googlegroups.com, Andrey Ryabinin , Thomas Sailer , linux-hams@vger.kernel.org, "Jason A. Donenfeld" , Richard Henderson , linux-alpha@vger.kernel.org, Russell King , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Huacai Chen , loongarch@lists.linux.dev, Geert Uytterhoeven , linux-m68k@lists.linux-m68k.org, Dinh Nguyen , Jonas Bonn , linux-openrisc@vger.kernel.org, Helge Deller , linux-parisc@vger.kernel.org, Michael Ellerman , linuxppc-dev@lists.ozlabs.org, Paul Walmsley , linux-riscv@lists.infradead.org, Heiko Carstens , linux-s390@vger.kernel.org, "David S. Miller" , sparclinux@vger.kernel.org Subject: Re: [patch 28/38] mips: Select ARCH_HAS_RANDOM_ENTROPY In-Reply-To: <20260410120319.462206386@kernel.org> Message-ID: References: <20260410120044.031381086@kernel.org> <20260410120319.462206386@kernel.org> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) Precedence: bulk X-Mailing-List: linux-fbdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII On Fri, 10 Apr 2026, Thomas Gleixner wrote: > The only solution for now is to uninline random_get_entropy(). Fix up all > other dependencies on the content of asm/timex.h in those files which > really depend on it. Oh dear! I'd yet have to fully evaluate the consequences, but offhand this has clearly turned what compiles to a single CPU instruction on the vast majority of MIPS platforms into an expensive function call, possibly also changing the caller from a leaf to a nested function with all the associated execution penalty. Is there no other way? Cf. commit 06947aaaf9bf ("MIPS: Implement random_get_entropy with CP0 Random"). Maciej