From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-f197.google.com (mail-qt0-f197.google.com [209.85.216.197]) by kanga.kvack.org (Postfix) with ESMTP id DC1EB6B0038 for ; Thu, 28 Sep 2017 12:32:47 -0400 (EDT) Received: by mail-qt0-f197.google.com with SMTP id o13so824195qtf.9 for ; Thu, 28 Sep 2017 09:32:47 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id t123si1822002qke.262.2017.09.28.09.32.47 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 28 Sep 2017 09:32:47 -0700 (PDT) From: Jeff Moyer Subject: Re: [PATCH 2/3] dax: stop using VM_MIXEDMAP for dax References: <150655617774.700.5326522538400299973.stgit@dwillia2-desk3.amr.corp.intel.com> <150655619012.700.15161500295945223238.stgit@dwillia2-desk3.amr.corp.intel.com> Date: Thu, 28 Sep 2017 12:32:44 -0400 In-Reply-To: <150655619012.700.15161500295945223238.stgit@dwillia2-desk3.amr.corp.intel.com> (Dan Williams's message of "Wed, 27 Sep 2017 16:49:50 -0700") Message-ID: MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: Dan Williams Cc: akpm@linux-foundation.org, Jan Kara , linux-nvdimm@lists.01.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Ross Zwisler , Christoph Hellwig Dan Williams writes: > Now that we always have pages for DAX we can stop setting VM_MIXEDMAP. > This does require some small fixups for the pte insert routines that dax > utilizes. It used to be that userspace would look to see if it had a 'mm' entry in /proc/pid/smaps to determine whether or not it got a direct mapping. Later, that same userspace (nvml) just uniformly declared dax not available from any Linux file system, since msync was required. And, I guess DAX has always been marked experimental, so the interface can be changed. All this is to say I guess it's fine to change this. > diff --git a/mm/mmap.c b/mm/mmap.c > index 680506faceae..d682f60670ff 100644 > --- a/mm/mmap.c > +++ b/mm/mmap.c > @@ -1111,7 +1111,7 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm, > * We later require that vma->vm_flags == vm_flags, > * so this tests vma->vm_flags & VM_SPECIAL, too. > */ > - if (vm_flags & VM_SPECIAL) > + if ((vm_flags & VM_SPECIAL)) > return NULL; That looks superfluous. -Jeff -- 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