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[2620:137:e000::1:20]) by mx.google.com with ESMTP id e16-20020a056a001a9000b00522c9732f7dsi24132514pfv.322.2022.07.08.10.15.08; Fri, 08 Jul 2022 10:15:43 -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=@intel.com header.s=Intel header.b=AF9LI4Ff; 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=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238479AbiGHRGR (ORCPT + 99 others); Fri, 8 Jul 2022 13:06:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48948 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238286AbiGHRGP (ORCPT ); Fri, 8 Jul 2022 13:06:15 -0400 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E1A66050E for ; Fri, 8 Jul 2022 10:06:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1657299975; x=1688835975; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=+ADmw6cOsgad1wiEE7DfCGuDQIqQwPGnx5VrvFmZZDU=; b=AF9LI4FfmSYo/fV+eCyDc8zE1/CQGgRbSqeTOTQkO74c+23R/aP7GQGi Osquo9jM1gk4XtnDkaiJdQ9YBBA9npRd8ImX1amizv5aKDlC+5bSDToz7 gmc6xkjyBtPT1wWu20c68zv5aoVVCrd7SR71Tvd77No6ngf39+Ztuwj9w AAwqFxI0Gkcib3ezhxV22hNn8WtUtj0QLuYRih61IuoSjkKOsbf5HbP1z WIYJmGwg9cEHjp7FgAdCub3DPBmHLhQguA/4YsFRq3doqaR7Uxfiq/ALT XkOoQcesZ7aiLD3D5K7uaXDJZ14OLNFB+g+yiu3XcXGOiRjqOAnPLTT/A g==; X-IronPort-AV: E=McAfee;i="6400,9594,10402"; a="283078441" X-IronPort-AV: E=Sophos;i="5.92,256,1650956400"; d="scan'208";a="283078441" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jul 2022 10:01:46 -0700 X-IronPort-AV: E=Sophos;i="5.92,256,1650956400"; d="scan'208";a="626764382" Received: from yyan2-mobl2.amr.corp.intel.com (HELO [10.212.242.16]) ([10.212.242.16]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jul 2022 10:01:45 -0700 Message-ID: Date: Fri, 8 Jul 2022 10:01:37 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Subject: Re: [PATCH] x86/mm/tlb: ignore f->new_tlb_gen when zero Content-Language: en-US To: Nadav Amit Cc: David Hildenbrand , LKML , Hugh Dickins , Thomas Gleixner , Ingo Molnar , Borislav Petkov , X86 ML , Linux MM , Dave Hansen , Peter Zijlstra , Andy Lutomirski References: <20220708003053.158480-1-namit@vmware.com> <283d7660-000a-81af-1d6b-4fdedcb6dfd8@intel.com> From: Dave Hansen In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-5.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A, RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE 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 7/8/22 09:54, Nadav Amit wrote: > Since the bug was not during MADV_DONTNEED there is no reason for the > results to be any different. > > Famous last words? Considering that your patch broke the kernel a way that surprised us all, I think caution is warranted. Re-running a microbenchmark that takes five minutes and stresses things a bit is the least you can do, I think.