From 3f0814bdbe411a58b5617787732bcf9660293410 Mon Sep 17 00:00:00 2001 From: Wei Yang Date: Sat, 30 Nov 2019 17:50:53 -0800 Subject: [PATCH] mm/mmap.c: rb_parent is not necessary in __vma_link_list() Now we use rb_parent to get next, while this is not necessary. When prev is NULL, this means vma should be the first element in the list. Then next should be current first one (mm->mmap), no matter whether we have parent or not. After removing it, the code shows the beauty of symmetry. Link: http://lkml.kernel.org/r/20190813032656.16625-1-richardw.yang@linux.intel.com Signed-off-by: Wei Yang Acked-by: Andrew Morton Cc: Mel Gorman Cc: Vlastimil Babka Cc: Matthew Wilcox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/internal.h | 2 +- mm/mmap.c | 2 +- mm/nommu.c | 2 +- mm/util.c | 8 ++------ 4 files changed, 5 insertions(+), 9 deletions(-) diff --git a/mm/internal.h b/mm/internal.h index 523d2a3ee923e..a246c516ade27 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -290,7 +290,7 @@ static inline bool is_data_mapping(vm_flags_t flags) /* mm/util.c */ void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, - struct vm_area_struct *prev, struct rb_node *rb_parent); + struct vm_area_struct *prev); void __vma_unlink_list(struct mm_struct *mm, struct vm_area_struct *vma); #ifdef CONFIG_MMU diff --git a/mm/mmap.c b/mm/mmap.c index 148b175352c97..311b08f780ce9 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -641,7 +641,7 @@ __vma_link(struct mm_struct *mm, struct vm_area_struct *vma, struct vm_area_struct *prev, struct rb_node **rb_link, struct rb_node *rb_parent) { - __vma_link_list(mm, vma, prev, rb_parent); + __vma_link_list(mm, vma, prev); __vma_link_rb(mm, vma, rb_link, rb_parent); } diff --git a/mm/nommu.c b/mm/nommu.c index 47a58b32fdc99..bd2b4e5ef1445 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -648,7 +648,7 @@ static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma) if (rb_prev) prev = rb_entry(rb_prev, struct vm_area_struct, vm_rb); - __vma_link_list(mm, vma, prev, parent); + __vma_link_list(mm, vma, prev); } /* diff --git a/mm/util.c b/mm/util.c index 7fbaadb7fb1f1..988d11e6c17cb 100644 --- a/mm/util.c +++ b/mm/util.c @@ -271,7 +271,7 @@ void *memdup_user_nul(const void __user *src, size_t len) EXPORT_SYMBOL(memdup_user_nul); void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, - struct vm_area_struct *prev, struct rb_node *rb_parent) + struct vm_area_struct *prev) { struct vm_area_struct *next; @@ -280,12 +280,8 @@ void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, next = prev->vm_next; prev->vm_next = vma; } else { + next = mm->mmap; mm->mmap = vma; - if (rb_parent) - next = rb_entry(rb_parent, - struct vm_area_struct, vm_rb); - else - next = NULL; } vma->vm_next = next; if (next) -- 2.39.5