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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 397BDCA5FCB for ; Thu, 1 Oct 2026 10:48:39 +0000 (UTC) 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:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=nvxzpDijyunSAV8wnMnOQWvCOYQAaanAYGbWsb1uvuA=; b=dWAFCgrG+1+SUL 4M/pv2YHNMyWwZqe9aYLGsODAi0iJI8VUumZW6wWq8UsGCmXK72Qq23Pcdf0cX6sFLzP8FkXBPwIu CVbKOCM74y+7J4bp4/R/izEV5RGIk/mjIExyTkNZU6Q/lkGvWfCs1CfJy+sP1cXXvEcwiIJQGI2QN I4Fp66zWNhlGZzoGv6wDW7AkxipUAgNIR1rWozD67feuAGfwZXx0eoh8fFI7sK55xnHb9iCh4+Wrs qHmoN5DLljV3D7PoXkuGEMMRR5hyyx85H/XKi76nY0gKsWTjAHYs1XPmNcEe0gNzlNE95iH5yAEo6 mnsjzZHGlDvpi32szTiw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xCEKt-00000008YKC-0U2Z; Thu, 01 Oct 2026 10:48:23 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xCEKr-00000008YJz-23uC; Thu, 01 Oct 2026 10:48:21 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id D801141768; Thu, 1 Oct 2026 10:48:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7D6031F000FF; Thu, 1 Oct 2026 10:48:17 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=zx2c4.com header.i=@zx2c4.com header.a=rsa-sha256 header.s=20210105 header.b=B57mDsY4 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1790851695; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=/oOpPY/gsh1NivZHQbt/4ewXmUw4hi2f8c5A+91XjAQ=; b=B57mDsY4+jopKLImXZNVOWxdVpQrgNONXSBu75IrKyl7123Al4mEDaeWWuv661fwT5QFtp DyBe8f04ARHZI529RupFjeyvDFHWlpXWFuVEmNR4jf9UiXLsJ+Xu0/uwQUzKXb1sdqw5Bu rwXQT6Por1A+lDJO9XzMggVf/BrbZ0A= Received: by mail.zx2c4.com (OpenSMTPD) with ESMTPSA id 03abc62d (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Thu, 1 Oct 2026 10:48:15 +0000 (UTC) Date: Thu, 1 Oct 2026 12:48:10 +0200 From: "Jason A. Donenfeld" To: Nathan Chancellor Cc: "Christophe Leroy (CS GROUP)" , Nick Desaulniers , Andy Lutomirski , Thomas Gleixner , Theodore Ts'o , Vincenzo Frascino , Bill Wendling , Justin Stitt , Catalin Marinas , Will Deacon , Mark Rutland , Huacai Chen , WANG Xuerui , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, llvm@lists.linux.dev Subject: Re: [PATCH v2] random: vDSO: Avoid call to memset() when zeroing reserved in __cvdso_getrandom_data() Message-ID: References: <20260930133813.GA3142230@ax162> <20260930151337.GD3142230@ax162> <20261001102059.GA4176271@ax162> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20261001102059.GA4176271@ax162> X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Thu, Oct 01, 2026 at 12:20:59PM +0200, Nathan Chancellor wrote: > control. The change that introduced -max-store-memset only did it to > "allow fine-tuning of the inlining threshold for performance analysis > and optimization". If they decide to remove it for whatever reason, > we're back to square one. I suppose all the more reason to get -finline-stringops=memset added to clang. Then the dual-default thing you came up with below will naturally start choosing the first option when it becomes available. > I know something like below would be uglier due to the ifdef but it > would avoid changing anything for GCC while clearing up the issue at > hand for clang in a guaranteed stable and succinct manner. But then we're back to the byte-by-byte codegen that Christophe pointed out. > If that is not acceptable, something like the following does appear to > work for me. Okay, great, let's do that. Does this commit seem okay with you? I used the diff you sent below and adjusted the commit message: https://git.zx2c4.com/linux-rng/commit/?id=56ff95ee85715047eb5b5220243778af657778c8 Jason _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv