From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751614AbcEJNeJ (ORCPT ); Tue, 10 May 2016 09:34:09 -0400 Received: from mail-qg0-f67.google.com ([209.85.192.67]:33393 "EHLO mail-qg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750910AbcEJNeI (ORCPT ); Tue, 10 May 2016 09:34:08 -0400 Date: Tue, 10 May 2016 15:34:01 +0200 From: Jerome Glisse To: Nicolas Morey Chaisemartin Cc: Hugh Dickins , Mel Gorman , Andrea Arcangeli , "Kirill A. Shutemov" , "Kirill A. Shutemov" , Alex Williamson , One Thousand Gnomes , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [Question] Missing data after DMA read transfer - mm issue with transparent huge page? Message-ID: <20160510133401.GB18820@gmail.com> References: <15edf085-c21b-aa1c-9f1f-057d17b8a1a3@morey-chaisemartin.com> <20160503101153.GA7241@gmail.com> <07619be9-e812-5459-26dd-ceb8c6490520@morey-chaisemartin.com> <20160510100104.GA18820@gmail.com> <80f878a0-f71b-2969-f2eb-05f4509ff58a@morey-chaisemartin.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <80f878a0-f71b-2969-f2eb-05f4509ff58a@morey-chaisemartin.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 10, 2016 at 01:15:02PM +0200, Nicolas Morey Chaisemartin wrote: > Le 05/10/2016 à 12:01 PM, Jerome Glisse a écrit : > > On Tue, May 10, 2016 at 09:04:36AM +0200, Nicolas Morey Chaisemartin wrote: > >> Le 05/03/2016 à 12:11 PM, Jerome Glisse a écrit : > >>> On Mon, May 02, 2016 at 09:04:02PM -0700, Hugh Dickins wrote: > >>>> On Fri, 29 Apr 2016, Nicolas Morey Chaisemartin wrote: [...] > >> Hi, > >> > >> I backported the patch to 3.10 (had to copy paste pmd_protnone defitinition from 4.5) and it's working ! > >> I'll open a ticket in Redhat tracker to try and get this fixed in RHEL7. > >> > >> I have a dumb question though: how can we end up in numa/misplaced memory code on a single socket system? > >> > > This patch is not a fix, do you see bug message in kernel log ? Because if > > you do that it means we have a bigger issue. > I don't see any on my 3.10. I have DMA_API_DEBUG enabled but I don't think it has an impact. My patch can't be backported to 3.10 as is, you most likely need to replace pmd_protnone() by pmd_numa() > > You did not answer one of my previous question, do you set get_user_pages > > with write = 1 as a paremeter ? > For the read from the device, yes: > down_read(¤t->mm->mmap_sem); > res = get_user_pages( > current, > current->mm, > (unsigned long) iov->host_addr, > page_count, > (write_mode == 0) ? 1 : 0, /* write */ > 0, /* force */ > &trans->pages[sg_o], > NULL); > up_read(¤t->mm->mmap_sem); As i don't have context to infer how write_mode is set above, do you mind retesting your driver and always asking for write no matter what ? > > Also it would be a lot easier if you were testing with lastest 4.6 or 4.5 > > not RHEL kernel as they are far appart and what might looks like same issue > > on both might be totaly different bugs. > Is a RPM from elrepo ok? > http://elrepo.org/linux/kernel/el7/SRPMS/ Yes should be ok for testing. Cheers, Jérôme From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vk0-f70.google.com (mail-vk0-f70.google.com [209.85.213.70]) by kanga.kvack.org (Postfix) with ESMTP id 275D46B007E for ; Tue, 10 May 2016 09:34:08 -0400 (EDT) Received: by mail-vk0-f70.google.com with SMTP id e126so24573642vkb.2 for ; Tue, 10 May 2016 06:34:08 -0700 (PDT) Received: from mail-qg0-x241.google.com (mail-qg0-x241.google.com. [2607:f8b0:400d:c04::241]) by mx.google.com with ESMTPS id l65si1431053qgd.61.2016.05.10.06.34.07 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 10 May 2016 06:34:07 -0700 (PDT) Received: by mail-qg0-x241.google.com with SMTP id e35so752189qge.1 for ; Tue, 10 May 2016 06:34:07 -0700 (PDT) Date: Tue, 10 May 2016 15:34:01 +0200 From: Jerome Glisse Subject: Re: [Question] Missing data after DMA read transfer - mm issue with transparent huge page? Message-ID: <20160510133401.GB18820@gmail.com> References: <15edf085-c21b-aa1c-9f1f-057d17b8a1a3@morey-chaisemartin.com> <20160503101153.GA7241@gmail.com> <07619be9-e812-5459-26dd-ceb8c6490520@morey-chaisemartin.com> <20160510100104.GA18820@gmail.com> <80f878a0-f71b-2969-f2eb-05f4509ff58a@morey-chaisemartin.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <80f878a0-f71b-2969-f2eb-05f4509ff58a@morey-chaisemartin.com> Sender: owner-linux-mm@kvack.org List-ID: To: Nicolas Morey Chaisemartin Cc: Hugh Dickins , Mel Gorman , Andrea Arcangeli , "Kirill A. Shutemov" , "Kirill A. Shutemov" , Alex Williamson , One Thousand Gnomes , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Tue, May 10, 2016 at 01:15:02PM +0200, Nicolas Morey Chaisemartin wrote: > Le 05/10/2016 a 12:01 PM, Jerome Glisse a ecrit : > > On Tue, May 10, 2016 at 09:04:36AM +0200, Nicolas Morey Chaisemartin wrote: > >> Le 05/03/2016 a 12:11 PM, Jerome Glisse a ecrit : > >>> On Mon, May 02, 2016 at 09:04:02PM -0700, Hugh Dickins wrote: > >>>> On Fri, 29 Apr 2016, Nicolas Morey Chaisemartin wrote: [...] > >> Hi, > >> > >> I backported the patch to 3.10 (had to copy paste pmd_protnone defitinition from 4.5) and it's working ! > >> I'll open a ticket in Redhat tracker to try and get this fixed in RHEL7. > >> > >> I have a dumb question though: how can we end up in numa/misplaced memory code on a single socket system? > >> > > This patch is not a fix, do you see bug message in kernel log ? Because if > > you do that it means we have a bigger issue. > I don't see any on my 3.10. I have DMA_API_DEBUG enabled but I don't think it has an impact. My patch can't be backported to 3.10 as is, you most likely need to replace pmd_protnone() by pmd_numa() > > You did not answer one of my previous question, do you set get_user_pages > > with write = 1 as a paremeter ? > For the read from the device, yes: > down_read(¤t->mm->mmap_sem); > res = get_user_pages( > current, > current->mm, > (unsigned long) iov->host_addr, > page_count, > (write_mode == 0) ? 1 : 0, /* write */ > 0, /* force */ > &trans->pages[sg_o], > NULL); > up_read(¤t->mm->mmap_sem); As i don't have context to infer how write_mode is set above, do you mind retesting your driver and always asking for write no matter what ? > > Also it would be a lot easier if you were testing with lastest 4.6 or 4.5 > > not RHEL kernel as they are far appart and what might looks like same issue > > on both might be totaly different bugs. > Is a RPM from elrepo ok? > http://elrepo.org/linux/kernel/el7/SRPMS/ Yes should be ok for testing. Cheers, 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