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 9BB03FD9E1A for ; Thu, 26 Feb 2026 22:00:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To: Content-Transfer-Encoding:Content-Type: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=3ilvamkoK822H0OMpkLt0O2v/cHCUl9aKFe1v6Kcca4=; b=OnTpQgf2lo0LCjE4SL8IzBur+J e78j+hEz/3S4qpGLvNV1ADc2Rb1In49XMcsX6ZI4sYRTPpDfVu2CjYPCc1MjxjORtd723sbjHvv0M nRllB0k6aqvKA3PNXdONAf/W9TTx2NmdgwiAQfu2x5O014FW9O/UbiOuxNEku5CepjWPSwNFXwekB WkpIwx7ACtlndvU+zA+wm7lMgNF+KmmRCGugJbMcol81f9faJInTrLZiU7Wp6rM5NQEpw9ItV5J+f QC80cpMiT4XhJNMdhZZzwCoHcUjBPvDISz3IGy09sLD5biHhUsz6eXstHpdNYpVuCCU1902+OOU6C 5DMwmx1Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vvjPh-00000007HL9-43F1; Thu, 26 Feb 2026 22:00:53 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vvjPe-00000007HKe-3ho6; Thu, 26 Feb 2026 22:00:52 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 3731168C4E; Thu, 26 Feb 2026 23:00:39 +0100 (CET) Date: Thu, 26 Feb 2026 23:00:38 +0100 From: hch To: Richard Weinberger Cc: hch , Andrew Morton , Richard Henderson , Matt Turner , Magnus Lindholm , Russell King , Catalin Marinas , will , Huacai Chen , WANG Xuerui , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , davem , Andreas Larsson , anton ivanov , Johannes Berg , Thomas Gleixner , mingo , bp , dave hansen , x86 , hpa , Herbert Xu , dan j williams , Chris Mason , David Sterba , Arnd Bergmann , Song Liu , Yu Kuai , Li Nan , linux-alpha , linux-kernel , linux-arm-kernel , loongarch , linuxppc-dev , linux-riscv , linux-s390 , sparclinux , linux-um , Linux Crypto Mailing List , linux-btrfs , linux-arch , linux-raid Subject: Re: [PATCH 03/25] um/xor: don't override XOR_SELECT_TEMPLATE Message-ID: <20260226220038.GA15172@lst.de> References: <20260226151106.144735-1-hch@lst.de> <20260226151106.144735-4-hch@lst.de> <445921547.2198.1772142326749.JavaMail.zimbra@nod.at> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <445921547.2198.1772142326749.JavaMail.zimbra@nod.at> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260226_140051_067374_DC1ABC15 X-CRM114-Status: GOOD ( 15.92 ) X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org On Thu, Feb 26, 2026 at 10:45:26PM +0100, Richard Weinberger wrote: > ----- Ursprüngliche Mail ----- > > Von: "hch" > > XOR_SELECT_TEMPLATE is only ever called with a NULL argument, so all the > > ifdef'ery doesn't do anything. With our without this, the time travel > > mode should work fine on CPUs that support AVX2, as the AVX2 > > implementation is forced in this case, and won't work otherwise. > > IIRC Johannes added XOR_SELECT_TEMPLATE() here to skip > the template selection logic because it didn't work with time travel mode. > > Johannes, can you please test whether this change does not break > time travel mode? I'm pretty sure that was the intent, but as I wrote above it worked and still works on AVX-supporting CPUs by chance, and already doesn't on older CPUs, and unless my git blaming went wrong someewhere already didn't when this was originally added.