From patchwork Wed Sep 7 22:26:14 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 9320187 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 452E0607D3 for ; Wed, 7 Sep 2016 22:29:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2543B2942F for ; Wed, 7 Sep 2016 22:29:15 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 19AE829443; Wed, 7 Sep 2016 22:29:15 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 0099E2942F for ; Wed, 7 Sep 2016 22:29:13 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 51A436E295; Wed, 7 Sep 2016 22:29:13 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by gabe.freedesktop.org (Postfix) with ESMTPS id 576E06E295 for ; Wed, 7 Sep 2016 22:29:12 +0000 (UTC) Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga103.jf.intel.com with ESMTP; 07 Sep 2016 15:29:13 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.30,297,1470726000"; d="scan'208";a="6158530" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.14]) by orsmga004.jf.intel.com with ESMTP; 07 Sep 2016 15:29:12 -0700 Subject: [PATCH v2 1/2] mm: fix cache mode of dax pmd mappings From: Dan Williams To: linux-nvdimm@lists.01.org Date: Wed, 07 Sep 2016 15:26:14 -0700 Message-ID: <147328717393.35069.6384193370523015106.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <147328716869.35069.16311932814998156819.stgit@dwillia2-desk3.amr.corp.intel.com> References: <147328716869.35069.16311932814998156819.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.17.1-9-g687f MIME-Version: 1.0 Cc: Toshi Kani , Matthew Wilcox , Nilesh Choudhury , linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux-mm@kvack.org, dri-devel@lists.freedesktop.org, Ross Zwisler , akpm@linux-foundation.org, "Kirill A. Shutemov" , Kai Zhang X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP track_pfn_insert() in vmf_insert_pfn_pmd() is marking dax mappings as uncacheable rendering them impractical for application usage. DAX-pte mappings are cached and the goal of establishing DAX-pmd mappings is to attain more performance, not dramatically less (3 orders of magnitude). track_pfn_insert() relies on a previous call to reserve_memtype() to establish the expected page_cache_mode for the range. While memremap() arranges for reserve_memtype() to be called, devm_memremap_pages() does not. So, teach track_pfn_insert() and untrack_pfn() how to handle tracking without a vma, and arrange for devm_memremap_pages() to establish the write-back-cache reservation in the memtype tree. Cc: Cc: Matthew Wilcox Cc: Andrew Morton Cc: Ross Zwisler Cc: Nilesh Choudhury Cc: Kirill A. Shutemov Reported-by: Toshi Kani Reported-by: Kai Zhang Signed-off-by: Dan Williams Acked-by: Andrew Morton --- arch/x86/mm/pat.c | 17 ++++++++++------- kernel/memremap.c | 9 +++++++++ 2 files changed, 19 insertions(+), 7 deletions(-) diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index ecb1b69c1651..170cc4ff057b 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -927,9 +927,10 @@ int track_pfn_copy(struct vm_area_struct *vma) } /* - * prot is passed in as a parameter for the new mapping. If the vma has a - * linear pfn mapping for the entire range reserve the entire vma range with - * single reserve_pfn_range call. + * prot is passed in as a parameter for the new mapping. If the vma has + * a linear pfn mapping for the entire range, or no vma is provided, + * reserve the entire pfn + size range with single reserve_pfn_range + * call. */ int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot, unsigned long pfn, unsigned long addr, unsigned long size) @@ -938,11 +939,12 @@ int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot, enum page_cache_mode pcm; /* reserve the whole chunk starting from paddr */ - if (addr == vma->vm_start && size == (vma->vm_end - vma->vm_start)) { + if (!vma || (addr == vma->vm_start + && size == (vma->vm_end - vma->vm_start))) { int ret; ret = reserve_pfn_range(paddr, size, prot, 0); - if (!ret) + if (ret == 0 && vma) vma->vm_flags |= VM_PAT; return ret; } @@ -997,7 +999,7 @@ void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn, resource_size_t paddr; unsigned long prot; - if (!(vma->vm_flags & VM_PAT)) + if (vma && !(vma->vm_flags & VM_PAT)) return; /* free the chunk starting from pfn or the whole chunk */ @@ -1011,7 +1013,8 @@ void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn, size = vma->vm_end - vma->vm_start; } free_pfn_range(paddr, size); - vma->vm_flags &= ~VM_PAT; + if (vma) + vma->vm_flags &= ~VM_PAT; } /* diff --git a/kernel/memremap.c b/kernel/memremap.c index 251d16b4cb41..b501e390bb34 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -247,6 +247,7 @@ static void devm_memremap_pages_release(struct device *dev, void *data) align_start = res->start & ~(SECTION_SIZE - 1); align_size = ALIGN(resource_size(res), SECTION_SIZE); arch_remove_memory(align_start, align_size); + untrack_pfn(NULL, PHYS_PFN(align_start), align_size); pgmap_radix_release(res); dev_WARN_ONCE(dev, pgmap->altmap && pgmap->altmap->alloc, "%s: failed to free all reserved pages\n", __func__); @@ -282,6 +283,7 @@ void *devm_memremap_pages(struct device *dev, struct resource *res, struct percpu_ref *ref, struct vmem_altmap *altmap) { resource_size_t key, align_start, align_size, align_end; + pgprot_t pgprot = PAGE_KERNEL; struct dev_pagemap *pgmap; struct page_map *page_map; int error, nid, is_ram; @@ -351,6 +353,11 @@ void *devm_memremap_pages(struct device *dev, struct resource *res, if (nid < 0) nid = numa_mem_id(); + error = track_pfn_remap(NULL, &pgprot, PHYS_PFN(align_start), 0, + align_size); + if (error) + goto err_pfn_remap; + error = arch_add_memory(nid, align_start, align_size, true); if (error) goto err_add_memory; @@ -371,6 +378,8 @@ void *devm_memremap_pages(struct device *dev, struct resource *res, return __va(res->start); err_add_memory: + untrack_pfn(NULL, PHYS_PFN(align_start), align_size); + err_pfn_remap: err_radix: pgmap_radix_release(res); devres_free(page_map);