From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f71.google.com (mail-it0-f71.google.com [209.85.214.71]) by kanga.kvack.org (Postfix) with ESMTP id 6450A6B0038 for ; Mon, 14 Nov 2016 20:06:24 -0500 (EST) Received: by mail-it0-f71.google.com with SMTP id l8so67726026iti.6 for ; Mon, 14 Nov 2016 17:06:24 -0800 (PST) Received: from mail-it0-x231.google.com (mail-it0-x231.google.com. [2607:f8b0:4001:c0b::231]) by mx.google.com with ESMTPS id y15si14243457ioe.241.2016.11.14.17.06.23 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 14 Nov 2016 17:06:23 -0800 (PST) Received: by mail-it0-x231.google.com with SMTP id q124so138363260itd.1 for ; Mon, 14 Nov 2016 17:06:23 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20161114162529.1a5b08ff90f6f199c1be8cc9@linux-foundation.org> References: <147892450132.22062.16875659431109209179.stgit@dwillia2-desk3.amr.corp.intel.com> <20161114162529.1a5b08ff90f6f199c1be8cc9@linux-foundation.org> From: Dan Williams Date: Mon, 14 Nov 2016 17:06:23 -0800 Message-ID: Subject: Re: [PATCH] mm: disable numa migration faults for dax vmas Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Michal Hocko , linux-nvdimm , "linux-kernel@vger.kernel.org" , Linux MM , "Kirill A. Shutemov" , Vlastimil Babka , "Aneesh Kumar K.V" On Mon, Nov 14, 2016 at 4:25 PM, Andrew Morton wrote: > On Fri, 11 Nov 2016 20:21:41 -0800 Dan Williams wrote: > >> Mark dax vmas as not migratable to exclude them from task_numa_work(). >> This is especially relevant for device-dax which wants to ensure >> predictable access latency and not incur periodic faults. >> >> ... >> >> @@ -177,6 +178,9 @@ static inline bool vma_migratable(struct vm_area_struct *vma) >> if (vma->vm_flags & (VM_IO | VM_PFNMAP)) >> return false; >> >> + if (vma_is_dax(vma)) >> + return false; >> + >> #ifndef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION >> if (vma->vm_flags & VM_HUGETLB) >> return false; > > I don't think the reader could figure out why this code is here, so... this? > > --- a/include/linux/mempolicy.h~mm-disable-numa-migration-faults-for-dax-vmas-fix > +++ a/include/linux/mempolicy.h > @@ -180,6 +180,10 @@ static inline bool vma_migratable(struct > if (vma->vm_flags & (VM_IO | VM_PFNMAP)) > return false; > > + /* > + * DAX device mappings require predictable access latency, so avoid > + * incurring periodic faults. > + */ > if (vma_is_dax(vma)) > return false; > Yes, thanks for fixing it up. -- 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