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From: yulei.kernel@gmail.com
To: linux-mm@kvack.org, akpm@linux-foundation.org,
	linux-fsdevel@vger.kernel.org, kvm@vger.kernel.org,
	linux-kernel@vger.kernel.org, naoya.horiguchi@nec.com,
	viro@zeniv.linux.org.uk, pbonzini@redhat.com
Cc: joao.m.martins@oracle.com, rdunlap@infradead.org,
	sean.j.christopherson@intel.com, xiaoguangrong.eric@gmail.com,
	kernellwp@gmail.com, lihaiwei.kernel@gmail.com,
	Yulei Zhang <yuleixzhang@tencent.com>,
	Chen Zhuo <sagazchen@tencent.com>
Subject: [RFC V2 21/37] mm: support dmem huge pmd for follow_pfn()
Date: Mon,  7 Dec 2020 19:31:14 +0800	[thread overview]
Message-ID: <c83a4e698999902057cdf8e3a662ec6837f6f466.1607332046.git.yuleixzhang@tencent.com> (raw)
In-Reply-To: <cover.1607332046.git.yuleixzhang@tencent.com>

From: Yulei Zhang <yuleixzhang@tencent.com>

follow_pfn() will get pfn of pmd if huge pmd is encountered.

Signed-off-by: Chen Zhuo <sagazchen@tencent.com>
Signed-off-by: Yulei Zhang <yuleixzhang@tencent.com>
---
 mm/memory.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 6b60981..abb9148 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4807,15 +4807,23 @@ int follow_pfn(struct vm_area_struct *vma, unsigned long address,
 	int ret = -EINVAL;
 	spinlock_t *ptl;
 	pte_t *ptep;
+	pmd_t *pmdp = NULL;
 
 	if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
 		return ret;
 
-	ret = follow_pte(vma->vm_mm, address, &ptep, &ptl);
+	ret = follow_pte_pmd(vma->vm_mm, address, NULL, &ptep, &pmdp, &ptl);
 	if (ret)
 		return ret;
-	*pfn = pte_pfn(*ptep);
-	pte_unmap_unlock(ptep, ptl);
+
+	if (pmdp) {
+		*pfn = pmd_pfn(*pmdp) + ((address & ~PMD_MASK) >> PAGE_SHIFT);
+		spin_unlock(ptl);
+	} else {
+		*pfn = pte_pfn(*ptep);
+		pte_unmap_unlock(ptep, ptl);
+	}
+
 	return 0;
 }
 EXPORT_SYMBOL(follow_pfn);
-- 
1.8.3.1



  parent reply	other threads:[~2020-12-07 11:34 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-07 11:30 [RFC V2 00/37] Enhance memory utilization with DMEMFS yulei.kernel
2020-12-07 11:30 ` [RFC V2 01/37] fs: introduce dmemfs module yulei.kernel
2020-12-07 11:30 ` [RFC V2 02/37] mm: support direct memory reservation yulei.kernel
2020-12-07 11:30 ` [RFC V2 03/37] dmem: implement dmem memory management yulei.kernel
2020-12-07 11:30 ` [RFC V2 04/37] dmem: let pat recognize dmem yulei.kernel
2020-12-07 11:30 ` [RFC V2 05/37] dmemfs: support mmap for dmemfs yulei.kernel
2020-12-07 11:30 ` [RFC V2 06/37] dmemfs: support truncating inode down yulei.kernel
2020-12-07 11:31 ` [RFC V2 07/37] dmem: trace core functions yulei.kernel
2020-12-07 11:31 ` [RFC V2 08/37] dmem: show some statistic in debugfs yulei.kernel
2020-12-07 11:31 ` [RFC V2 09/37] dmemfs: support remote access yulei.kernel
2020-12-07 11:31 ` [RFC V2 10/37] dmemfs: introduce max_alloc_try_dpages parameter yulei.kernel
2020-12-07 11:31 ` [RFC V2 11/37] mm: export mempolicy interfaces to serve dmem allocator yulei.kernel
2020-12-07 11:31 ` [RFC V2 12/37] dmem: introduce mempolicy support yulei.kernel
2020-12-07 11:31 ` [RFC V2 13/37] mm, dmem: introduce PFN_DMEM and pfn_t_dmem yulei.kernel
2020-12-07 11:31 ` [RFC V2 14/37] mm, dmem: differentiate dmem-pmd and thp-pmd yulei.kernel
2020-12-07 11:31 ` [RFC V2 15/37] mm: add pmd_special() check for pmd_trans_huge_lock() yulei.kernel
2020-12-07 11:31 ` [RFC V2 16/37] dmemfs: introduce ->split() to dmemfs_vm_ops yulei.kernel
2020-12-07 11:31 ` [RFC V2 17/37] mm, dmemfs: support unmap_page_range() for dmemfs pmd yulei.kernel
2020-12-07 11:31 ` [RFC V2 18/37] mm: follow_pmd_mask() for dmem huge pmd yulei.kernel
2020-12-07 11:31 ` [RFC V2 19/37] mm: gup_huge_pmd() " yulei.kernel
2020-12-07 11:31 ` [RFC V2 20/37] mm: support dmem huge pmd for vmf_insert_pfn_pmd() yulei.kernel
2020-12-07 11:31 ` yulei.kernel [this message]
2020-12-07 11:31 ` [RFC V2 22/37] kvm, x86: Distinguish dmemfs page from mmio page yulei.kernel
2020-12-07 11:31 ` [RFC V2 23/37] kvm, x86: introduce VM_DMEM for syscall support usage yulei.kernel
2020-12-07 11:31 ` [RFC V2 24/37] dmemfs: support hugepage for dmemfs yulei.kernel
2020-12-07 11:31 ` [RFC V2 25/37] mm, x86, dmem: fix estimation of reserved page for vaddr_get_pfn() yulei.kernel
2020-12-07 11:31 ` [RFC V2 26/37] mm, dmem: introduce pud_special() for dmem huge pud support yulei.kernel
2020-12-07 11:31 ` [RFC V2 27/37] mm: add pud_special() check to support dmem huge pud yulei.kernel
2020-12-07 11:31 ` [RFC V2 28/37] mm, dmemfs: support huge_fault() for dmemfs yulei.kernel
2020-12-07 11:31 ` [RFC V2 29/37] mm: add follow_pte_pud() to support huge pud look up yulei.kernel
2020-12-07 11:31 ` [RFC V2 30/37] dmem: introduce dmem_bitmap_alloc() and dmem_bitmap_free() yulei.kernel
2020-12-07 11:31 ` [RFC V2 31/37] dmem: introduce mce handler yulei.kernel
2020-12-07 11:31 ` [RFC V2 32/37] mm, dmemfs: register and handle the dmem mce yulei.kernel
2020-12-07 11:31 ` [RFC V2 33/37] kvm, x86: enable record_steal_time for dmem yulei.kernel
2020-12-07 11:31 ` [RFC V2 34/37] dmem: add dmem unit tests yulei.kernel
2020-12-07 11:31 ` [RFC V2 35/37] mm, dmem: introduce dregion->memmap for dmem yulei.kernel
2020-12-07 11:31 ` [RFC V2 36/37] vfio: support dmempage refcount for vfio yulei.kernel
2020-12-07 11:31 ` [RFC V2 37/37] Add documentation for dmemfs yulei.kernel
2020-12-24 18:27   ` Randy Dunlap
2020-12-07 12:02 ` [RFC V2 00/37] Enhance memory utilization with DMEMFS David Hildenbrand
2020-12-07 19:32   ` Dan Williams

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