From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755360AbdJIQ0w (ORCPT ); Mon, 9 Oct 2017 12:26:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42850 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755332AbdJIQ0h (ORCPT ); Mon, 9 Oct 2017 12:26:37 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 92C51C058EA8 Authentication-Results: ext-mx08.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx08.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=dledford@redhat.com Message-ID: <1507566396.46071.40.camel@redhat.com> Subject: Re: [PATCH] infiniband: add MMU dependency for user_mem From: Doug Ledford To: Arnd Bergmann , Sean Hefty , Hal Rosenstock Cc: Yuval Shaia , linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org Date: Mon, 09 Oct 2017 12:26:36 -0400 In-Reply-To: <20171006071410.732275-1-arnd@arndb.de> References: <20171006071410.732275-1-arnd@arndb.de> Organization: Red Hat, Inc. Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Mon, 09 Oct 2017 16:26:37 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2017-10-06 at 09:13 +0200, Arnd Bergmann wrote: > The infiniband subsystem causes a link failure when the umem > driver is built on MMU-less systems: > > mm/mmu_notifier.o: In function `do_mmu_notifier_register': > mmu_notifier.c:(.text+0x32): undefined reference to > `mm_take_all_locks' > drivers/infiniband/core/umem.o: In function `ib_umem_get': > umem.c:(.text+0x132): undefined reference to `can_do_mlock' > drivers/infiniband/core/umem_odp.o: In function > `ib_umem_odp_map_dma_pages': > umem_odp.c:(.text+0x766): undefined reference to > `get_user_pages_remote' > > This bug has existed for a while but only become apparent in ARM > randconfig builds when the dependency on PCI was lifted, as none > of the ARM-NOMMU targets support PCI at the moment. > > We could probably get the umem driver to build by providing an > alternative implementation 'can_do_mlock()' that returns false > on NOMMU-systems, but then we'd still have a problem with the > mmu-notifiers required by CONFIG_INFINIBAND_ON_DEMAND_PAGING, > so simply forbidding umem with NOMMU seems like the simplest > workaround. > > Fixes: 931bc0d91639 ("IB: Move PCI dependency from root KConfig to > HW's KConfigs") > Signed-off-by: Arnd Bergmann Thanks, applied. -- Doug Ledford GPG KeyID: B826A3330E572FDD Key fingerprint = AE6B 1BDA 122B 23B4 265B 1274 B826 A333 0E57 2FDD