From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-f199.google.com (mail-qt0-f199.google.com [209.85.216.199]) by kanga.kvack.org (Postfix) with ESMTP id 4DD6E6B02F4 for ; Mon, 26 Jun 2017 10:49:39 -0400 (EDT) Received: by mail-qt0-f199.google.com with SMTP id g2so1194183qta.14 for ; Mon, 26 Jun 2017 07:49:39 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id f19si251249qtc.27.2017.06.26.07.49.38 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 26 Jun 2017 07:49:38 -0700 (PDT) Date: Mon, 26 Jun 2017 10:49:34 -0400 From: Jerome Glisse Subject: Re: [PATCH] x86/mm/hotplug: fix BUG_ON() after hotremove by not freeing pud v3 Message-ID: <20170626144934.GA3706@redhat.com> References: <20170624180514.3821-1-jglisse@redhat.com> <20170626094304.bmvsia5zpixbazpu@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20170626094304.bmvsia5zpixbazpu@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Ingo Molnar Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andy Lutomirski , Logan Gunthorpe , Andrew Morton On Mon, Jun 26, 2017 at 11:43:04AM +0200, Ingo Molnar wrote: > > * jglisse@redhat.com wrote: > > > From: Jerome Glisse > > > > With commit af2cf278ef4f we no longer free pud so that we do not > > have synchronize all pgd on hotremove/vfree. But the new 5 level > > page table patchset reverted that for 4 level page table. > > > > This patch restore af2cf278ef4f and disable free_pud() if we are > > in the 4 level page table case thus avoiding BUG_ON() after hot- > > remove. > > > > af2cf278ef4f x86/mm/hotplug: Don't remove PGD entries in remove_pagetable() > > Am I correct that the _real_ buggy commit that introduced the breakage in v4.12 > is: > > f2a6a7050109: ("x86: Convert the rest of the code to support p4d_t") > > ... right? Correct. Jerome -- 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