From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pb0-f43.google.com (mail-pb0-f43.google.com [209.85.160.43]) by kanga.kvack.org (Postfix) with ESMTP id 7C4256B0035 for ; Thu, 13 Mar 2014 22:31:08 -0400 (EDT) Received: by mail-pb0-f43.google.com with SMTP id um1so1948407pbc.16 for ; Thu, 13 Mar 2014 19:31:08 -0700 (PDT) Received: from mail-pd0-x229.google.com (mail-pd0-x229.google.com [2607:f8b0:400e:c02::229]) by mx.google.com with ESMTPS id e6si2122717pbj.163.2014.03.13.19.31.07 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 13 Mar 2014 19:31:07 -0700 (PDT) Received: by mail-pd0-f169.google.com with SMTP id fp1so1909933pdb.28 for ; Thu, 13 Mar 2014 19:31:07 -0700 (PDT) From: john.hubbard@gmail.com Subject: [PATCH] A long explanation for a short patch Date: Thu, 13 Mar 2014 19:30:45 -0700 Message-Id: <1394764246-19936-1-git-send-email-jhubbard@nvidia.com> Sender: owner-linux-mm@kvack.org List-ID: To: Sasha Levin Cc: "Kirill A. Shutemov" , linux-mm@kvack.org, John Hubbard From: John Hubbard Hi Sasha and linux-mm, Prior to commit 309381feaee564281c3d9e90fbca8963bb7428ad, it was possible to build MIT-licensed (non-GPL) drivers on Fedora. Fedora is semi-unique, in that it sets CONFIG_VM_DEBUG. Because Fedora sets CONFIG_VM_DEBUG, they end up pulling in dump_page(), via VM_BUG_ON_PAGE, via get_page(). As one of the authors of NVIDIA's new, open source, "UVM-Lite" kernel module, I originally choose to use the kernel's get_page() routine from within nvidia_uvm_page_cache.c, because get_page() has always seemed to be very clearly intended for use by non-GPL, driver code. So I'm hoping that making get_page() widely accessible again will not be too controversial. We did check with Fedora first, and they responded (https://bugzilla.redhat.com/show_bug.cgi?id=1074710#c3) that we should try to get upstream changed, before asking Fedora to change. Their reasoning seems beneficial to Linux: leaving CONFIG_DEBUG_VM set allows Fedora to help catch mm bugs. thanks, John h John Hubbard (1): Change mm debug routines back to EXPORT_SYMBOL mm/page_alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 1.9.0 -- 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