From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f200.google.com (mail-io0-f200.google.com [209.85.223.200]) by kanga.kvack.org (Postfix) with ESMTP id 211426B0261 for ; Wed, 15 Jun 2016 16:26:50 -0400 (EDT) Received: by mail-io0-f200.google.com with SMTP id l5so66836366ioa.0 for ; Wed, 15 Jun 2016 13:26:50 -0700 (PDT) Received: from mail-pa0-x242.google.com (mail-pa0-x242.google.com. [2607:f8b0:400e:c03::242]) by mx.google.com with ESMTPS id zd7si904060pac.177.2016.06.15.13.26.49 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 15 Jun 2016 13:26:49 -0700 (PDT) Received: by mail-pa0-x242.google.com with SMTP id hf6so2133513pac.2 for ; Wed, 15 Jun 2016 13:26:49 -0700 (PDT) Content-Type: text/plain; charset=windows-1252 Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) Subject: Re: [PATCH v2] Linux VM workaround for Knights Landing A/D leak From: Nadav Amit In-Reply-To: <5761B630.7020502@linux.intel.com> Date: Wed, 15 Jun 2016 13:26:46 -0700 Content-Transfer-Encoding: quoted-printable Message-Id: References: <7FB15233-B347-4A87-9506-A9E10D331292@gmail.com> <1465923672-14232-1-git-send-email-lukasz.anaczkowski@intel.com> <76F6D5F2-6723-441B-BD63-52628731F1FF@gmail.com> <613007E2-2A88-4934-9364-A5A66A555305@gmail.com> <5761B630.7020502@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: "Anaczkowski, Lukasz" , LKML , "linux-mm@kvack.org" , Thomas Gleixner , Ingo Molnar , "ak@linux.intel.com" , "kirill.shutemov@linux.intel.com" , "mhocko@suse.com" , Andrew Morton , "H. Peter Anvin" , "Srinivasappa, Harish" , "Odzioba, Lukasz" , "Andrejczuk, Grzegorz" , "Daniluk, Lukasz" Dave Hansen wrote: > On 06/15/2016 01:04 PM, Nadav Amit wrote: >> Be careful here. According to the SDM when invalidating a huge-page, >> each 4KB page needs to be invalidated separately. In practice, when >> Linux invalidates 2MB/1GB pages it performs a full TLB flush. The >> full flush may not be required on knights landing, and specifically >> for the workaround, but you should check. =20 >=20 > Where do you get that? The SDM says: "they (TLB invalidation = operations > invalidate all TLB entries corresponding to the translation specified = by > the paging structures.=94 You are absolutely correct. Last time I write something based on my recollection of the SDM without re-reading again. Sorry. Nadav -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org