From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f70.google.com (mail-wm0-f70.google.com [74.125.82.70]) by kanga.kvack.org (Postfix) with ESMTP id 402D36B0292 for ; Mon, 26 Jun 2017 05:43:10 -0400 (EDT) Received: by mail-wm0-f70.google.com with SMTP id s65so324390wma.15 for ; Mon, 26 Jun 2017 02:43:10 -0700 (PDT) Received: from mail-wr0-x241.google.com (mail-wr0-x241.google.com. [2a00:1450:400c:c0c::241]) by mx.google.com with ESMTPS id g186si8352022wmf.196.2017.06.26.02.43.07 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 26 Jun 2017 02:43:07 -0700 (PDT) Received: by mail-wr0-x241.google.com with SMTP id z45so28895554wrb.2 for ; Mon, 26 Jun 2017 02:43:07 -0700 (PDT) Date: Mon, 26 Jun 2017 11:43:04 +0200 From: Ingo Molnar Subject: Re: [PATCH] x86/mm/hotplug: fix BUG_ON() after hotremove by not freeing pud v3 Message-ID: <20170626094304.bmvsia5zpixbazpu@gmail.com> References: <20170624180514.3821-1-jglisse@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20170624180514.3821-1-jglisse@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: jglisse@redhat.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andy Lutomirski , Logan Gunthorpe , Andrew Morton * 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? Thanks, Ingo -- 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