From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751540AbcCHTxe (ORCPT ); Tue, 8 Mar 2016 14:53:34 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51043 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751072AbcCHTrM (ORCPT ); Tue, 8 Mar 2016 14:47:12 -0500 From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= To: akpm@linux-foundation.org, , linux-mm@kvack.org Cc: Linus Torvalds , , Mel Gorman , "H. Peter Anvin" , Peter Zijlstra , Andrea Arcangeli , Johannes Weiner , Larry Woodman , Rik van Riel , Dave Airlie , Brendan Conoboy , Joe Donohue , Christophe Harle , Duncan Poole , Sherry Cheung , Subhash Gutti , John Hubbard , Mark Hairgrove , Lucien Dunning , Cameron Buschardt , Arvind Gopalakrishnan , Haggai Eran , Shachar Raindel , Liran Liss , Roland Dreier , Ben Sander , Greg Stoner , John Bridgman , Michael Mantor , Paul Blinzer , Leonid Shamis , Laurent Morichetti , Alexander Deucher , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= Subject: [PATCH v12 14/29] HMM: Add support for hugetlb. Date: Tue, 8 Mar 2016 15:43:07 -0500 Message-Id: <1457469802-11850-15-git-send-email-jglisse@redhat.com> In-Reply-To: <1457469802-11850-1-git-send-email-jglisse@redhat.com> References: <1457469802-11850-1-git-send-email-jglisse@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Support hugetlb vma allmost like other vma. Exception being that we will not support migration of hugetlb memory. Signed-off-by: Jérôme Glisse --- mm/hmm.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 61 insertions(+), 1 deletion(-) diff --git a/mm/hmm.c b/mm/hmm.c index 7cab6cb..ad44325 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -813,6 +813,65 @@ static int hmm_mirror_fault_pmd(pmd_t *pmdp, return ret; } +static int hmm_mirror_fault_hugetlb_entry(pte_t *ptep, + unsigned long hmask, + unsigned long addr, + unsigned long end, + struct mm_walk *walk) +{ +#ifdef CONFIG_HUGETLB_PAGE + struct hmm_mirror_fault *mirror_fault = walk->private; + struct hmm_event *event = mirror_fault->event; + struct hmm_pt_iter *iter = mirror_fault->iter; + bool write = (event->etype == HMM_DEVICE_WFAULT); + unsigned long pfn, next; + dma_addr_t *hmm_pte; + pte_t pte; + + /* + * Hugepages under user process are always in RAM and never + * swapped out, but theoretically it needs to be checked. + */ + if (!ptep) + return -ENOENT; + + pte = huge_ptep_get(ptep); + pfn = pte_pfn(pte); + if (!huge_pte_none(pte) || (write && !huge_pte_write(pte))) + return -ENOENT; + + hmm_pte = hmm_pt_iter_populate(iter, addr, &next); + if (!hmm_pte) + return -ENOMEM; + hmm_pt_iter_directory_lock(iter); + for (; addr != end; addr += PAGE_SIZE, ++pfn, ++hmm_pte) { + /* Switch to another HMM page table directory ? */ + if (addr == next) { + hmm_pt_iter_directory_unlock(iter); + hmm_pte = hmm_pt_iter_populate(iter, addr, &next); + if (!hmm_pte) + return -ENOMEM; + hmm_pt_iter_directory_lock(iter); + } + + if (hmm_pte_test_valid_dma(hmm_pte)) + continue; + + if (!hmm_pte_test_valid_pfn(hmm_pte)) { + *hmm_pte = hmm_pte_from_pfn(pfn); + hmm_pt_iter_directory_ref(iter); + } + BUG_ON(hmm_pte_pfn(*hmm_pte) != pfn); + if (write) + hmm_pte_set_write(hmm_pte); + } + hmm_pt_iter_directory_unlock(iter); +#else + BUG(); +#endif + return 0; +} + static int hmm_mirror_dma_map(struct hmm_mirror *mirror, struct hmm_pt_iter *iter, unsigned long start, @@ -920,6 +979,7 @@ static int hmm_mirror_handle_fault(struct hmm_mirror *mirror, walk.mm = mirror->hmm->mm; walk.private = &mirror_fault; walk.pmd_entry = hmm_mirror_fault_pmd; + walk.hugetlb_entry = hmm_mirror_fault_hugetlb_entry; walk.pte_hole = hmm_pte_hole; ret = walk_page_range(addr, event->end, &walk); if (ret) @@ -1006,7 +1066,7 @@ retry: goto out; } event->end = min(event->end, vma->vm_end) & PAGE_MASK; - if ((vma->vm_flags & (VM_IO | VM_PFNMAP | VM_MIXEDMAP | VM_HUGETLB))) { + if ((vma->vm_flags & (VM_IO | VM_PFNMAP | VM_MIXEDMAP))) { ret = -EFAULT; goto out; } -- 2.4.3