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From: Liam Howlett <liam.howlett@oracle.com>
To: "maple-tree@lists.infradead.org" <maple-tree@lists.infradead.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>
Cc: Song Liu <songliubraving@fb.com>,
	Davidlohr Bueso <dave@stgolabs.net>,
	"Paul E . McKenney" <paulmck@kernel.org>,
	Matthew Wilcox <willy@infradead.org>,
	Laurent Dufour <ldufour@linux.ibm.com>,
	David Rientjes <rientjes@google.com>,
	Axel Rasmussen <axelrasmussen@google.com>,
	Suren Baghdasaryan <surenb@google.com>,
	Vlastimil Babka <vbabka@suse.cz>, Rik van Riel <riel@surriel.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Michel Lespinasse <walken.cr@gmail.com>,
	Liam Howlett <liam.howlett@oracle.com>
Subject: [PATCH v2 16/61] mm: Use maple tree operations for find_vma_intersection() and find_vma()
Date: Tue, 17 Aug 2021 15:47:13 +0000	[thread overview]
Message-ID: <20210817154651.1570984-17-Liam.Howlett@oracle.com> (raw)
In-Reply-To: <20210817154651.1570984-1-Liam.Howlett@oracle.com>

From: "Liam R. Howlett" <Liam.Howlett@Oracle.com>

Move find_vma_intersection() to mmap.c and change implementation to
maple tree.

When searching for a vma within a range, it is easier to use the maple
tree interface.  This means the find_vma() call changes to a special
case of the find_vma_intersection().

Exported for kvm module.

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---
 include/linux/mm.h | 25 ++++++-------------------
 mm/mmap.c          | 38 ++++++++++++++++++++++++++++----------
 2 files changed, 34 insertions(+), 29 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index a3086474d8d2..10763bd6fccb 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2774,26 +2774,13 @@ extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long add
 extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr,
 					     struct vm_area_struct **pprev);
 
-/**
- * find_vma_intersection() - Look up the first VMA which intersects the interval
- * @mm: The process address space.
- * @start_addr: The inclusive start user address.
- * @end_addr: The exclusive end user address.
- *
- * Returns: The first VMA within the provided range, %NULL otherwise.  Assumes
- * start_addr < end_addr.
+/*
+ * Look up the first VMA which intersects the interval [start_addr, end_addr)
+ * NULL if none.  Assume start_addr < end_addr.
  */
-static inline
-struct vm_area_struct *find_vma_intersection(struct mm_struct *mm,
-					     unsigned long start_addr,
-					     unsigned long end_addr)
-{
-	struct vm_area_struct *vma = find_vma(mm, start_addr);
-
-	if (vma && end_addr <= vma->vm_start)
-		vma = NULL;
-	return vma;
-}
+extern struct vm_area_struct *find_vma_intersection(struct mm_struct *mm,
+						    unsigned long start_addr,
+						    unsigned long end_addr);
 
 /**
  * vma_lookup() - Find a VMA at a specific address
diff --git a/mm/mmap.c b/mm/mmap.c
index 3d88fc87c289..9b86f47f7387 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2052,32 +2052,50 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
 EXPORT_SYMBOL(get_unmapped_area);
 
 /**
- * find_vma() - Find the VMA for a given address, or the next vma.
- * @mm: The mm_struct to check
- * @addr: The address
+ * find_vma_intersection() - Look up the first VMA which intersects the interval
+ * @mm: The process address space.
+ * @start_addr: The inclusive start user address.
+ * @end_addr: The exclusive end user address.
  *
- * Returns: The VMA associated with addr, or the next vma.
- * May return %NULL in the case of no vma at addr or above.
+ * Returns: The first VMA within the provided range, %NULL otherwise.  Assumes
+ * start_addr < end_addr.
  */
-struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
+struct vm_area_struct *find_vma_intersection(struct mm_struct *mm,
+					     unsigned long start_addr,
+					     unsigned long end_addr)
 {
 	struct vm_area_struct *vma;
-	MA_STATE(mas, &mm->mm_mt, addr, addr);
+	MA_STATE(mas, &mm->mm_mt, start_addr, start_addr);
 
 	mmap_assert_locked(mm);
 	/* Check the cache first. */
-	vma = vmacache_find(mm, addr);
+	vma = vmacache_find(mm, start_addr);
 	if (likely(vma))
 		return vma;
 
 	rcu_read_lock();
-	vma = mas_find(&mas, -1);
+	vma = mas_find(&mas, end_addr - 1);
 	rcu_read_unlock();
 	if (vma)
-		vmacache_update(addr, vma);
+		vmacache_update(mas.index, vma);
 
 	return vma;
 }
+EXPORT_SYMBOL(find_vma_intersection);
+
+/**
+ * find_vma() - Find the VMA for a given address, or the next vma.
+ * @mm:  The mm_struct to check
+ * @addr: The address
+ *
+ * Returns: The VMA associated with addr, or the next vma.
+ * May return NULL in the case of no vma at addr or above.
+ */
+inline struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
+{
+	// Note find_vma_intersection will decrease 0 to underflow to ULONG_MAX
+	return find_vma_intersection(mm, addr, 0);
+}
 EXPORT_SYMBOL(find_vma);
 
 /**
-- 
2.30.2

  parent reply	other threads:[~2021-08-17 15:52 UTC|newest]

Thread overview: 67+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-17 15:47 [PATCH v2 00/61] Introducing the Maple Tree Liam Howlett
2021-08-17 15:47 ` [PATCH v2 01/61] radix tree test suite: Add pr_err define Liam Howlett
2021-08-17 15:47 ` [PATCH v2 04/61] radix tree test suite: Add support for slab bulk APIs Liam Howlett
2021-08-17 15:47 ` [PATCH v2 02/61] radix tree test suite: Add kmem_cache_set_non_kernel() Liam Howlett
2021-08-17 15:47 ` [PATCH v2 03/61] radix tree test suite: Add allocation counts and size to kmem_cache Liam Howlett
2021-08-17 15:47 ` [PATCH v2 05/61] Maple Tree: Add new data structure Liam Howlett
2021-08-17 15:47 ` [PATCH v2 06/61] mm: Start tracking VMAs with maple tree Liam Howlett
2021-08-17 15:47 ` [PATCH v2 07/61] mm/mmap: Use the maple tree in find_vma() instead of the rbtree Liam Howlett
2021-08-17 15:47 ` [PATCH v2 09/61] mm/mmap: Use maple tree for unmapped_area{_topdown} Liam Howlett
2021-08-17 15:47 ` [PATCH v2 08/61] mm/mmap: Use the maple tree for find_vma_prev() instead of the rbtree Liam Howlett
2021-08-17 15:47 ` [PATCH v2 10/61] kernel/fork: Use maple tree for dup_mmap() during forking Liam Howlett
2021-08-17 15:47 ` [PATCH v2 12/61] xen/privcmd: Optimized privcmd_ioctl_mmap() by using vma_lookup() Liam Howlett
2021-08-17 15:47 ` [PATCH v2 13/61] mm: Optimize find_exact_vma() to use vma_lookup() Liam Howlett
2021-08-17 15:47 ` [PATCH v2 11/61] mm: Remove rb tree Liam Howlett
2021-08-23  9:49   ` David Hildenbrand
2021-08-31 14:40     ` Liam Howlett
2021-08-17 15:47 ` Liam Howlett [this message]
2021-08-17 15:47 ` [PATCH v2 15/61] mm/mmap: Change do_brk_flags() to expand existing VMA and add do_brk_munmap() Liam Howlett
2021-08-17 15:47 ` [PATCH v2 17/61] mm/mmap: Use advanced maple tree API for mmap_region() Liam Howlett
2021-08-17 15:47 ` [PATCH v2 14/61] mm/khugepaged: Optimize collapse_pte_mapped_thp() by using vma_lookup() Liam Howlett
2021-08-17 15:47 ` [PATCH v2 18/61] mm: Remove vmacache Liam Howlett
2021-08-17 15:47 ` [PATCH v2 19/61] mm/mmap: Move mmap_region() below do_munmap() Liam Howlett
2021-08-17 15:47 ` [PATCH v2 21/61] mm/mmap: Reorganize munmap to use maple states Liam Howlett
2021-08-17 15:47 ` [PATCH v2 20/61] mm/mmap: Convert count_vma_pages_range() to use ma_state Liam Howlett
2021-08-17 15:47 ` [PATCH v2 22/61] mm/mmap: Change do_brk_munmap() to use do_mas_align_munmap() Liam Howlett
2021-08-17 15:47 ` [PATCH v2 24/61] arch/arm64: Remove mmap linked list from vdso Liam Howlett
2021-08-17 15:47 ` [PATCH v2 23/61] mm: Introduce vma_next() and vma_prev() Liam Howlett
2021-08-17 15:47 ` [PATCH v2 26/61] arch/powerpc: Remove mmap linked list from mm/book3s32/tlb Liam Howlett
2021-08-17 15:47 ` [PATCH v2 25/61] arch/parisc: Remove mmap linked list from kernel/cache Liam Howlett
2021-08-17 15:47 ` [PATCH v2 28/61] arch/s390: Use maple tree iterators instead of linked list Liam Howlett
2021-08-17 15:47 ` [PATCH v2 27/61] arch/powerpc: Remove mmap linked list from mm/book3s64/subpage_prot Liam Howlett
2021-08-17 15:47 ` [PATCH v2 31/61] drivers/misc/cxl: Use maple tree iterators for cxl_prefault_vma() Liam Howlett
2021-08-17 15:47 ` [PATCH v2 30/61] arch/xtensa: Use maple tree iterators for unmapped area Liam Howlett
2021-08-17 15:47 ` [PATCH v2 29/61] arch/x86: Use maple tree iterators for vdso/vma Liam Howlett
2021-08-17 15:47 ` [PATCH v2 33/61] fs/binfmt_elf: Use maple tree iterators for fill_files_note() Liam Howlett
2021-08-17 15:47 ` [PATCH v2 32/61] drivers/tee/optee: Use maple tree iterators for __check_mem_type() Liam Howlett
2021-08-17 15:47 ` [PATCH v2 34/61] fs/coredump: Use maple tree iterators in place of linked list Liam Howlett
2021-08-17 15:47 ` [PATCH v2 38/61] fs/userfaultfd: Stop using vma " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 37/61] fs/proc/task_mmu: Stop using linked list and highest_vm_end Liam Howlett
2021-08-17 15:47 ` [PATCH v2 36/61] fs/proc/base: Use maple tree iterators in place of linked list Liam Howlett
2021-08-17 15:47 ` [PATCH v2 35/61] fs/exec: Use vma_next() instead " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 39/61] ipc/shm: Stop using the vma " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 41/61] kernel/events/core: Use maple tree iterators instead of " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 40/61] kernel/acct: " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 45/61] arch/um/kernel/tlb: Stop using " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 42/61] kernel/events/uprobes: Use maple tree iterators instead of " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 44/61] kernel/sys: " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 43/61] kernel/sched/fair: " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 46/61] bpf: Remove VMA " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 48/61] mm/khugepaged: Use maple tree iterators instead of vma " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 47/61] mm/gup: Use maple tree navigation instead of " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 51/61] mm/memcontrol: Stop using mm->highest_vm_end Liam Howlett
2021-08-17 15:47 ` [PATCH v2 49/61] mm/ksm: Use maple tree iterators instead of vma linked list Liam Howlett
2021-08-17 15:47 ` [PATCH v2 52/61] mm/mempolicy: " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 50/61] mm/madvise: Use vma_next " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 54/61] mm/mprotect: Use maple tree navigation " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 56/61] mm/msync: Use vma_next() " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 53/61] mm/mlock: Use maple tree iterators " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 55/61] mm/mremap: Use vma_next() " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 57/61] mm/oom_kill: Use maple tree iterators " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 59/61] mm/swapfile: Use maple tree iterator " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 58/61] mm/pagewalk: Use vma_next() " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 60/61] mm: Remove the " Liam Howlett
2021-08-17 15:47 ` [PATCH v2 61/61] mm/mmap: Drop range_has_overlap() function Liam Howlett
     [not found] ` <20210818083610.3698-1-hdanton@sina.com>
2021-08-18 14:54   ` [PATCH v2 10/61] kernel/fork: Use maple tree for dup_mmap() during forking Liam Howlett
     [not found]   ` <20210819020105.3756-1-hdanton@sina.com>
2021-08-19 13:32     ` Liam Howlett
2021-08-20 17:45     ` Liam Howlett

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