From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 86D7EC43381 for ; Wed, 13 Feb 2019 23:24:40 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A4224218AC for ; Wed, 13 Feb 2019 23:24:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A4224218AC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 440Fwj6VsLzDqGh for ; Thu, 14 Feb 2019 10:24:37 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=intel.com (client-ip=134.134.136.65; helo=mga03.intel.com; envelope-from=ira.weiny@intel.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=intel.com Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 440FVc2pQxzDqVP for ; Thu, 14 Feb 2019 10:05:28 +1100 (AEDT) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 13 Feb 2019 15:05:26 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,366,1544515200"; d="scan'208";a="138415618" Received: from iweiny-desk2.sc.intel.com ([10.3.52.157]) by orsmga001.jf.intel.com with ESMTP; 13 Feb 2019 15:05:24 -0800 From: ira.weiny@intel.com To: linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, kvm@vger.kernel.org, linux-fpga@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, linux-scsi@vger.kernel.org, devel@driverdev.osuosl.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-fbdev@vger.kernel.org, xen-devel@lists.xenproject.org, devel@lists.orangefs.org, linux-mm@kvack.org, ceph-devel@vger.kernel.org, rds-devel@oss.oracle.com Subject: [PATCH V2 4/7] mm/gup: Add FOLL_LONGTERM capability to GUP fast Date: Wed, 13 Feb 2019 15:04:52 -0800 Message-Id: <20190213230455.5605-5-ira.weiny@intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190213230455.5605-1-ira.weiny@intel.com> References: <20190211201643.7599-1-ira.weiny@intel.com> <20190213230455.5605-1-ira.weiny@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Mailman-Approved-At: Thu, 14 Feb 2019 10:16:37 +1100 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Martin Brandenburg , Rich Felker , David Hildenbrand , David Airlie , Jason Wang , =?UTF-8?q?Kai=20M=C3=A4kisara?= , Michal Hocko , Ira Weiny , Ben Chan , Rob Springer , Todd Poynor , Yoshinori Sato , Joerg Roedel , "Michael S. Tsirkin" , Jason Gunthorpe , Ingo Molnar , Wu Hao , Alan Tull , John Hubbard , "James E.J. Bottomley" , Alex Williamson , Stefano Stabellini , Borislav Petkov , Alexander Viro , Thomas Gleixner , Mauro Carvalho Chehab , Peter Zijlstra , "Martin K. Petersen" , Dennis Dalessandro , Cornelia Huck , Jens Wiklander , Alexandre Bounine , Bartlomiej Zolnierkiewicz , Daniel Vetter , Moritz Fischer , Andrew Morton , "David S. Miller" , "Kirill A. Shutemov" , Christian Benvenuti Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: Ira Weiny DAX pages were previously unprotected from longterm pins when users called get_user_pages_fast(). Use the new FOLL_LONGTERM flag to check for DEVMAP pages and fall back to regular GUP processing if a DEVMAP page is encountered. Signed-off-by: Ira Weiny --- mm/gup.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index 6f32d36b3c5b..f7e759c523bb 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1439,6 +1439,9 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end, goto pte_unmap; if (pte_devmap(pte)) { + if (unlikely(flags & FOLL_LONGTERM)) + goto pte_unmap; + pgmap = get_dev_pagemap(pte_pfn(pte), pgmap); if (unlikely(!pgmap)) { undo_dev_pagemap(nr, nr_start, pages); @@ -1578,8 +1581,11 @@ static int gup_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr, if (!pmd_access_permitted(orig, flags & FOLL_WRITE)) return 0; - if (pmd_devmap(orig)) + if (pmd_devmap(orig)) { + if (unlikely(flags & FOLL_LONGTERM)) + return 0; return __gup_device_huge_pmd(orig, pmdp, addr, end, pages, nr); + } refs = 0; page = pmd_page(orig) + ((addr & ~PMD_MASK) >> PAGE_SHIFT); @@ -1904,8 +1910,20 @@ int get_user_pages_fast(unsigned long start, int nr_pages, start += nr << PAGE_SHIFT; pages += nr; - ret = get_user_pages_unlocked(start, nr_pages - nr, pages, - gup_flags); + if (gup_flags & FOLL_LONGTERM) { + down_read(¤t->mm->mmap_sem); + ret = __gup_longterm_locked(current, current->mm, + start, nr_pages - nr, + pages, NULL, gup_flags); + up_read(¤t->mm->mmap_sem); + } else { + /* + * retain FAULT_FOLL_ALLOW_RETRY optimization if + * possible + */ + ret = get_user_pages_unlocked(start, nr_pages - nr, + pages, gup_flags); + } /* Have to be a bit careful with return values */ if (nr > 0) { -- 2.20.1