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[2620:137:e000::1:20]) by mx.google.com with ESMTP id i19-20020aa796f3000000b0064d3e86948esi4201530pfq.115.2023.06.21.06.50.54; Wed, 21 Jun 2023 06:51:09 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@alien8.de header.s=dkim header.b=TWLu2AYw; dkim=pass header.i=@alien8.de header.s=alien8 header.b=F0SzsK0Q; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=alien8.de Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232343AbjFUNKP (ORCPT + 99 others); Wed, 21 Jun 2023 09:10:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44408 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232345AbjFUNKL (ORCPT ); Wed, 21 Jun 2023 09:10:11 -0400 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 50CCCE57 for ; Wed, 21 Jun 2023 06:10:08 -0700 (PDT) Received: from mail.alien8.de (mail.alien8.de [65.109.113.108]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id A7EC41EC03C0; Wed, 21 Jun 2023 15:10:06 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1687353006; 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: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=dShN/AtqsESo0zmQWkLwx8/tPFGQXcWK2Qh/w4XV2Hk=; b=TWLu2AYwh5/N2Bm9Xaa6h7SThIoekd8cfEtDE8AOtwAXTjcDUBUdH+WC+Ln1RzFr4WxYvo 1iTPSOYHvnymLPX1DcM5UrUu5AC1TvR+g5UMbemT+Cj/Qw3VxZsvEytCmcNvLUHVizUkkw hX5OsTB9ThGtApZ4BBtpx7WYq0Y0tiE= X-Virus-Scanned: Debian amavisd-new at mail.alien8.de Authentication-Results: mail.alien8.de (amavisd-new); dkim=pass (4096-bit key) header.d=alien8.de Received: from mail.alien8.de ([127.0.0.1]) by localhost (mail.alien8.de [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id nSGXzeZ7wJH4; Wed, 21 Jun 2023 13:10:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=alien8; t=1687353004; bh=dShN/AtqsESo0zmQWkLwx8/tPFGQXcWK2Qh/w4XV2Hk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=F0SzsK0QiMQd6TUvTd0Xu95T2QL111iE3+T4ycofW8zyahk8VIdo6wfelfUd2dwYi DuovVcLRVlwP9gYTmS7mMpGBm148o3/xIiA284EmwXf07QrryHL2H70OdFZ1Y8RzyO 5r4sdONN2eGCZ8Lhhml8/yJp7jPBX6pKOdbGbiGmP7Foaf64+oNhXAGKn1ZX9OTw6p 3kOr6EQGWQ+DSA16ekO5MxANth4O7bINFfucrClJ2CkayFq8zdZx96yiLvi1yI59TR 861B9vUX5ARmv5BUalsjfLSOwznl9zTsVQmoqAihlglBzU3Q0Ydit0HnpSi2hD79QK qOjl/tnVSl8Fu300DIrG/EJ+AW/NugNbI3qG6HfimGshf2GhyUnAYm9DK4B2vjdPs8 gqp47kU4MspN41CVpT1bD/o92Ci5SPhlgAvYmpS9YGvLOD7Qn7ISuhWTmQFEDDrTCQ XWWMAUBtSHIx6wFsGwLbCRMrDQhOY7mm30R7rSrK7EdJDQoLpv7JJK6lnFwXFSHwjh SMx3BFe6KAsfeONI11n8X6hpZEuWnIbLnBFVuQ1uhnzQ1hISE4IHQZOumh6e2+ST2y hut5ySOI8vooSoWtvybRiPYiJRMHumIooMtvWPsfnFPu7NBmT1gjuI6cblYubW7Ucq o1r0n3ifGvNH+s4QKriUYCZw= Received: from zn.tnic (p200300ea971dc565329c23fffea6a903.dip0.t-ipconnect.de [IPv6:2003:ea:971d:c565:329c:23ff:fea6:a903]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature ECDSA (P-256) server-digest SHA256) (No client certificate requested) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 5044940E019B; Wed, 21 Jun 2023 13:10:00 +0000 (UTC) Date: Wed, 21 Jun 2023 15:09:55 +0200 From: Borislav Petkov To: Xi Ruoyao Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Thomas Gleixner Subject: Re: A question about prefetchw detection in "x86/asm: Cleanup prefetch primitives" Message-ID: <20230621130955.GHZJL2o771lIEPURUl@fat_crate.local> References: <0b663d8f6802e8dbf443397718234bcb6d0811c8.camel@xry111.site> <20230621111346.GFZJLbavDw1JiLi34n@fat_crate.local> <20230621125749.GGZJLzzUw0rA3goV1X@fat_crate.local> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_NONE,SPF_PASS, T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 21, 2023 at 09:06:51PM +0800, Xi Ruoyao wrote: > I think it's not an issue in the kernel itself, but announcing > 3dnowprefetch in /proc/cpuinfo for an old Intel CPU w/o real prefetchw > implementation seems problematic (to me). And this is a problem because? Think practically. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette