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 X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E4E9BC433DB for ; Tue, 19 Jan 2021 15:36:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9AD9A2070C for ; Tue, 19 Jan 2021 15:36:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389130AbhASPfy (ORCPT ); Tue, 19 Jan 2021 10:35:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38432 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391544AbhASPen (ORCPT ); Tue, 19 Jan 2021 10:34:43 -0500 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 71E5DC061574 for ; Tue, 19 Jan 2021 07:33:58 -0800 (PST) Received: from zn.tnic (p200300ec2f0bca00ae49d9fe8335ba6f.dip0.t-ipconnect.de [IPv6:2003:ec:2f0b:ca00:ae49:d9fe:8335:ba6f]) (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 C8BDB1EC0608; Tue, 19 Jan 2021 16:33:56 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1611070436; 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=dKMeMKvzsrD0kIurpDZTCz5aerm1J86c9j6bD3+ekvI=; b=W7uNUiaZ0JNz4dHB6uEfh0QKxlZ80U3sA/6FAb/2E89KA1W4+hK2shiuELcPlx5PX4SNAy fturupYF0QnWbIC/oO7JPaCPPCJj7gU+3ERd/lhcy/PK2e4BEA7f3p9+x9BHzg10COFPMk FH1vIsOaPMqUIG/cfpYRsTghVePCqdg= Date: Tue, 19 Jan 2021 16:33:50 +0100 From: Borislav Petkov To: Feng Tang Cc: "Paul E. McKenney" , kernel test robot , Jonathan Lemon , Tony Luck , LKML , x86@kernel.org, lkp@lists.01.org, lkp@intel.com, ying.huang@intel.com, zhengjun.xing@intel.com Subject: Re: [x86/mce] 7bb39313cd: netperf.Throughput_tps -4.5% regression Message-ID: <20210119153350.GM27433@zn.tnic> References: <20210112142109.GE30747@xsang-OptiPlex-9020> <20210112141438.GF13086@zn.tnic> <20210116035251.GB29609@shbuild999.sh.intel.com> <20210116153413.GP2743@paulmck-ThinkPad-P72> <20210116160921.GA101665@shbuild999.sh.intel.com> <20210119042721.GA12664@paulmck-ThinkPad-P72> <20210119100255.GC27433@zn.tnic> <20210119121505.GA111354@shbuild999.sh.intel.com> <20210119131759.GL27433@zn.tnic> <20210119150903.GA21908@shbuild999.sh.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210119150903.GA21908@shbuild999.sh.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 19, 2021 at 11:09:03PM +0800, Feng Tang wrote: > Yes, that can happen. I started a 4 tasks netperf on a 4C/8T KBL desktop, > and also saw around 2% improvement. Both the kernel config and the > platform matters. Oh great. ;-\ > For the performance changes I have checked, sometimes the change can be > reproduced on platforms of different generations (the exact delta number > may differs), sometimes it can only be reproduced on one specific platform, > like some old generation, or special one like Xeon Phi. Probably because that Xeon Phi thing is not as powerful cache-wise as some newer ones which have bigger caches and smarter hw prefetchers, etc. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette