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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 A128AC433E1 for ; Sat, 22 Aug 2020 11:32:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 64DAD207DA for ; Sat, 22 Aug 2020 11:32:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 64DAD207DA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=chris-wilson.co.uk Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id EB89B6B00A7; Sat, 22 Aug 2020 07:32:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E41646B00A9; Sat, 22 Aug 2020 07:32:27 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D58278D0008; Sat, 22 Aug 2020 07:32:27 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0175.hostedemail.com [216.40.44.175]) by kanga.kvack.org (Postfix) with ESMTP id BD13F6B00A7 for ; Sat, 22 Aug 2020 07:32:27 -0400 (EDT) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 7BE73824556B for ; Sat, 22 Aug 2020 11:32:27 +0000 (UTC) X-FDA: 77177991534.06.ocean36_0f0e0ab27041 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin06.hostedemail.com (Postfix) with ESMTP id 35CCE10048EEB for ; Sat, 22 Aug 2020 11:32:27 +0000 (UTC) X-HE-Tag: ocean36_0f0e0ab27041 X-Filterd-Recvd-Size: 2745 Received: from fireflyinternet.com (unknown [77.68.26.236]) by imf13.hostedemail.com (Postfix) with ESMTP for ; Sat, 22 Aug 2020 11:32:26 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from localhost (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP (TLS) id 22207247-1500050 for multiple; Sat, 22 Aug 2020 12:31:56 +0100 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable In-Reply-To: <159805314945.32652.6355592202796435703@build.alporthouse.com> References: <20200821123746.16904-1-joro@8bytes.org> <20200821153412.5902e4ed0699615d8de4a595@linux-foundation.org> <159805314945.32652.6355592202796435703@build.alporthouse.com> Subject: Re: [PATCH v2] mm: Track page table modifications in __apply_to_page_range() From: Chris Wilson Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, Pavel Machek , Linus Torvalds , Dave Airlie , Joonas Lahtinen , Rodrigo Vivi , David Vrabel , Joerg Roedel , stable@vger.kernel.org To: Andrew Morton , Joerg Roedel Date: Sat, 22 Aug 2020 12:31:55 +0100 Message-ID: <159809591535.32652.4016790228519688343@build.alporthouse.com> User-Agent: alot/0.9 X-Rspamd-Queue-Id: 35CCE10048EEB X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Quoting Chris Wilson (2020-08-22 00:39:09) > Quoting Andrew Morton (2020-08-21 23:34:12) > > On Fri, 21 Aug 2020 14:37:46 +0200 Joerg Roedel wrote: > >=20 > > > The __apply_to_page_range() function is also used to change and/or > > > allocate page-table pages in the vmalloc area of the address space. > > > Make sure these changes get synchronized to other page-tables in the > > > system by calling arch_sync_kernel_mappings() when necessary. > > >=20 > > > Tested-by: Chris Wilson #x86-32 > > > Cc: # v5.8+ > >=20 > > I'm trying to figure out how you figured out that this is 5.8+. Has a > > particular misbehaving commit been identified? >=20 > The two commits of relevance, in my eyes, were >=20 > 2ba3e6947aed ("mm/vmalloc: track which page-table levels were modified") > 86cf69f1d893 ("x86/mm/32: implement arch_sync_kernel_mappings()") >=20 > I can reproduce the failure on v5.8, but not on v5.7. A bisect would > seem to be plausible. The active ingredient was 7f0a002b5a21 ("x86/mm: remove vmalloc faulting") which explains a lot. -Chris