From 09357814778a38a5ab2d031cba6c9e9fe090c849 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Thu, 5 Nov 2015 18:48:17 -0800 Subject: [PATCH] mm: add the "struct mm_struct *mm" local into Cosmetic, but expand_upwards() and expand_downwards() overuse vma->vm_mm, a local variable makes sense imho. Signed-off-by: Oleg Nesterov Acked-by: Hugh Dickins Cc: Andrey Konovalov Cc: Davidlohr Bueso Cc: "Kirill A. Shutemov" Cc: Sasha Levin Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mmap.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index d1ac22485998..3204a7e82430 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2148,6 +2148,7 @@ static int acct_stack_growth(struct vm_area_struct *vma, unsigned long size, uns */ int expand_upwards(struct vm_area_struct *vma, unsigned long address) { + struct mm_struct *mm = vma->vm_mm; int error; if (!(vma->vm_flags & VM_GROWSUP)) @@ -2197,10 +2198,10 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address) * So, we reuse mm->page_table_lock to guard * against concurrent vma expansions. */ - spin_lock(&vma->vm_mm->page_table_lock); + spin_lock(&mm->page_table_lock); if (vma->vm_flags & VM_LOCKED) - vma->vm_mm->locked_vm += grow; - vm_stat_account(vma->vm_mm, vma->vm_flags, + mm->locked_vm += grow; + vm_stat_account(mm, vma->vm_flags, vma->vm_file, grow); anon_vma_interval_tree_pre_update_vma(vma); vma->vm_end = address; @@ -2208,8 +2209,8 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address) if (vma->vm_next) vma_gap_update(vma->vm_next); else - vma->vm_mm->highest_vm_end = address; - spin_unlock(&vma->vm_mm->page_table_lock); + mm->highest_vm_end = address; + spin_unlock(&mm->page_table_lock); perf_event_mmap(vma); } @@ -2217,7 +2218,7 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address) } vma_unlock_anon_vma(vma); khugepaged_enter_vma_merge(vma, vma->vm_flags); - validate_mm(vma->vm_mm); + validate_mm(mm); return error; } #endif /* CONFIG_STACK_GROWSUP || CONFIG_IA64 */ @@ -2228,6 +2229,7 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address) int expand_downwards(struct vm_area_struct *vma, unsigned long address) { + struct mm_struct *mm = vma->vm_mm; int error; /* @@ -2272,17 +2274,17 @@ int expand_downwards(struct vm_area_struct *vma, * So, we reuse mm->page_table_lock to guard * against concurrent vma expansions. */ - spin_lock(&vma->vm_mm->page_table_lock); + spin_lock(&mm->page_table_lock); if (vma->vm_flags & VM_LOCKED) - vma->vm_mm->locked_vm += grow; - vm_stat_account(vma->vm_mm, vma->vm_flags, + mm->locked_vm += grow; + vm_stat_account(mm, vma->vm_flags, vma->vm_file, grow); anon_vma_interval_tree_pre_update_vma(vma); vma->vm_start = address; vma->vm_pgoff -= grow; anon_vma_interval_tree_post_update_vma(vma); vma_gap_update(vma); - spin_unlock(&vma->vm_mm->page_table_lock); + spin_unlock(&mm->page_table_lock); perf_event_mmap(vma); } @@ -2290,7 +2292,7 @@ int expand_downwards(struct vm_area_struct *vma, } vma_unlock_anon_vma(vma); khugepaged_enter_vma_merge(vma, vma->vm_flags); - validate_mm(vma->vm_mm); + validate_mm(mm); return error; } -- GitLab