From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f199.google.com (mail-pf0-f199.google.com [209.85.192.199]) by kanga.kvack.org (Postfix) with ESMTP id CE8896B0009 for ; Thu, 1 Mar 2018 22:58:14 -0500 (EST) Received: by mail-pf0-f199.google.com with SMTP id j12so1295588pff.18 for ; Thu, 01 Mar 2018 19:58:14 -0800 (PST) Received: from mga14.intel.com (mga14.intel.com. [192.55.52.115]) by mx.google.com with ESMTPS id a6-v6si4013805plz.497.2018.03.01.19.58.13 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 01 Mar 2018 19:58:13 -0800 (PST) Subject: [PATCH v3 2/3] mm, hugetlbfs: introduce ->pagesize() to vm_operations_struct From: Dan Williams Date: Thu, 01 Mar 2018 19:49:07 -0800 Message-ID: <151996254734.27922.15813097401404359642.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <151996253609.27922.9983044853291257359.stgit@dwillia2-desk3.amr.corp.intel.com> References: <151996253609.27922.9983044853291257359.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org Cc: Jane Chu , linux-mm@kvack.org, linux-nvdimm@lists.01.org When device-dax is operating in huge-page mode we want it to behave like hugetlbfs and report the MMU page mapping size that is being enforced by the vma. Similar to commit 31383c6865a5 "mm, hugetlbfs: introduce ->split() to vm_operations_struct" it would be messy to teach vma_mmu_pagesize() about device-dax page mapping sizes in the same (hstate) way that hugetlbfs communicates this attribute. Instead, these patches introduce a new ->pagesize() vm operation. Reported-by: Jane Chu Signed-off-by: Dan Williams --- include/linux/mm.h | 1 + mm/hugetlb.c | 19 +++++++++++-------- 2 files changed, 12 insertions(+), 8 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index ad06d42adb1a..be0040c9f81b 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -383,6 +383,7 @@ struct vm_operations_struct { int (*huge_fault)(struct vm_fault *vmf, enum page_entry_size pe_size); void (*map_pages)(struct vm_fault *vmf, pgoff_t start_pgoff, pgoff_t end_pgoff); + unsigned long (*pagesize)(struct vm_area_struct * area); /* notification that a previously read-only page is about to become * writable, if an error is returned it will cause a SIGBUS */ diff --git a/mm/hugetlb.c b/mm/hugetlb.c index f9c4ea42b04a..aaafe5ebaa3e 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -636,14 +636,9 @@ EXPORT_SYMBOL_GPL(linear_hugepage_index); */ unsigned long vma_kernel_pagesize(struct vm_area_struct *vma) { - struct hstate *hstate; - - if (!is_vm_hugetlb_page(vma)) - return PAGE_SIZE; - - hstate = hstate_vma(vma); - - return 1UL << huge_page_shift(hstate); + if (vma->vm_ops && vma->vm_ops->pagesize) + return vma->vm_ops->pagesize(vma); + return PAGE_SIZE; } EXPORT_SYMBOL_GPL(vma_kernel_pagesize); @@ -3150,6 +3145,13 @@ static int hugetlb_vm_op_split(struct vm_area_struct *vma, unsigned long addr) return 0; } +static unsigned long hugetlb_vm_op_pagesize(struct vm_area_struct *vma) +{ + struct hstate *hstate = hstate_vma(vma); + + return 1UL << huge_page_shift(hstate); +} + /* * We cannot handle pagefaults against hugetlb pages at all. They cause * handle_mm_fault() to try to instantiate regular-sized pages in the @@ -3167,6 +3169,7 @@ const struct vm_operations_struct hugetlb_vm_ops = { .open = hugetlb_vm_op_open, .close = hugetlb_vm_op_close, .split = hugetlb_vm_op_split, + .pagesize = hugetlb_vm_op_pagesize, }; static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, -- 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