From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751499AbdFFTu1 (ORCPT ); Tue, 6 Jun 2017 15:50:27 -0400 Received: from ale.deltatee.com ([207.54.116.67]:55486 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751440AbdFFTuR (ORCPT ); Tue, 6 Jun 2017 15:50:17 -0400 To: =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <20170606173512.7378-1-jglisse@redhat.com> Cc: Andy Lutomirski , Ingo Molnar , "Kirill A . Shutemov" From: Logan Gunthorpe Message-ID: <7b8534ee-8d07-8a9a-5b80-c16725033ee9@deltatee.com> Date: Tue, 6 Jun 2017 13:50:14 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <20170606173512.7378-1-jglisse@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 172.16.1.111 X-SA-Exim-Rcpt-To: kirill.shutemov@linux.intel.com, mingo@kernel.org, luto@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, jglisse@redhat.com X-SA-Exim-Mail-From: logang@deltatee.com Subject: Re: [PATCH] x86/mm/hotplug: fix BUG_ON() after hotremove X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thanks Jerome! This indeed fixes the bug I reported. Tested-by: Logan Gunthorpe Logan On 06/06/17 11:35 AM, Jérôme Glisse wrote: > 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 code re-added that code f2a6a705 and > thus we now trigger a BUG_ON() l128 in sync_global_pgds() > > This patch remove free_pud() like in af2cf278ef4f > > Signed-off-by: Jérôme Glisse > Cc: Andy Lutomirski > Cc: Ingo Molnar > Cc: Kirill A. Shutemov > Cc: Logan Gunthorpe > --- > arch/x86/mm/init_64.c | 19 ------------------- > 1 file changed, 19 deletions(-) > > diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c > index a8a9972..8cf7e99 100644 > --- a/arch/x86/mm/init_64.c > +++ b/arch/x86/mm/init_64.c > @@ -772,24 +772,6 @@ static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud) > spin_unlock(&init_mm.page_table_lock); > } > > -static void __meminit free_pud_table(pud_t *pud_start, p4d_t *p4d) > -{ > - pud_t *pud; > - int i; > - > - for (i = 0; i < PTRS_PER_PUD; i++) { > - pud = pud_start + i; > - if (!pud_none(*pud)) > - return; > - } > - > - /* free a pud talbe */ > - free_pagetable(p4d_page(*p4d), 0); > - spin_lock(&init_mm.page_table_lock); > - p4d_clear(p4d); > - spin_unlock(&init_mm.page_table_lock); > -} > - > static void __meminit > remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end, > bool direct) > @@ -991,7 +973,6 @@ remove_p4d_table(p4d_t *p4d_start, unsigned long addr, unsigned long end, > > pud_base = pud_offset(p4d, 0); > remove_pud_table(pud_base, addr, next, direct); > - free_pud_table(pud_base, p4d); > } > > if (direct) >