From 2b575eb64f7a9c701fb4bfdb12388ac547f6c2b6 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 24 May 2011 17:12:11 -0700 Subject: [PATCH] mm: convert anon_vma->lock to a mutex Straightforward conversion of anon_vma->lock to a mutex. Signed-off-by: Peter Zijlstra Acked-by: Hugh Dickins Reviewed-by: KOSAKI Motohiro Cc: Benjamin Herrenschmidt Cc: David Miller Cc: Martin Schwidefsky Cc: Russell King Cc: Paul Mundt Cc: Jeff Dike Cc: Richard Weinberger Cc: Tony Luck Cc: KAMEZAWA Hiroyuki Cc: Mel Gorman Cc: Nick Piggin Cc: Namhyung Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/huge_mm.h | 8 ++------ include/linux/mmu_notifier.h | 2 +- include/linux/rmap.h | 14 +++++++------- mm/huge_memory.c | 4 ++-- mm/mmap.c | 10 +++++----- mm/rmap.c | 8 ++++---- 6 files changed, 21 insertions(+), 25 deletions(-) diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 8847c8c29791..48c32ebf65a7 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -92,12 +92,8 @@ extern void __split_huge_page_pmd(struct mm_struct *mm, pmd_t *pmd); #define wait_split_huge_page(__anon_vma, __pmd) \ do { \ pmd_t *____pmd = (__pmd); \ - spin_unlock_wait(&(__anon_vma)->root->lock); \ - /* \ - * spin_unlock_wait() is just a loop in C and so the \ - * CPU can reorder anything around it. \ - */ \ - smp_mb(); \ + anon_vma_lock(__anon_vma); \ + anon_vma_unlock(__anon_vma); \ BUG_ON(pmd_trans_splitting(*____pmd) || \ pmd_trans_huge(*____pmd)); \ } while (0) diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index a877dfc243eb..1d1b1e13f79f 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -150,7 +150,7 @@ struct mmu_notifier_ops { * Therefore notifier chains can only be traversed when either * * 1. mmap_sem is held. - * 2. One of the reverse map locks is held (i_mmap_mutex or anon_vma->lock). + * 2. One of the reverse map locks is held (i_mmap_mutex or anon_vma->mutex). * 3. No other concurrent thread can access the list (release) */ struct mmu_notifier { diff --git a/include/linux/rmap.h b/include/linux/rmap.h index 590c291a8cd9..2148b122779b 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -7,7 +7,7 @@ #include #include #include -#include +#include #include /* @@ -26,7 +26,7 @@ */ struct anon_vma { struct anon_vma *root; /* Root of this anon_vma tree */ - spinlock_t lock; /* Serialize access to vma list */ + struct mutex mutex; /* Serialize access to vma list */ /* * The refcount is taken on an anon_vma when there is no * guarantee that the vma of page tables will exist for @@ -64,7 +64,7 @@ struct anon_vma_chain { struct vm_area_struct *vma; struct anon_vma *anon_vma; struct list_head same_vma; /* locked by mmap_sem & page_table_lock */ - struct list_head same_anon_vma; /* locked by anon_vma->lock */ + struct list_head same_anon_vma; /* locked by anon_vma->mutex */ }; #ifdef CONFIG_MMU @@ -93,24 +93,24 @@ static inline void vma_lock_anon_vma(struct vm_area_struct *vma) { struct anon_vma *anon_vma = vma->anon_vma; if (anon_vma) - spin_lock(&anon_vma->root->lock); + mutex_lock(&anon_vma->root->mutex); } static inline void vma_unlock_anon_vma(struct vm_area_struct *vma) { struct anon_vma *anon_vma = vma->anon_vma; if (anon_vma) - spin_unlock(&anon_vma->root->lock); + mutex_unlock(&anon_vma->root->mutex); } static inline void anon_vma_lock(struct anon_vma *anon_vma) { - spin_lock(&anon_vma->root->lock); + mutex_lock(&anon_vma->root->mutex); } static inline void anon_vma_unlock(struct anon_vma *anon_vma) { - spin_unlock(&anon_vma->root->lock); + mutex_unlock(&anon_vma->root->mutex); } /* diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 83326ad66d9b..90eef404ec2e 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1139,7 +1139,7 @@ static int __split_huge_page_splitting(struct page *page, * We can't temporarily set the pmd to null in order * to split it, the pmd must remain marked huge at all * times or the VM won't take the pmd_trans_huge paths - * and it won't wait on the anon_vma->root->lock to + * and it won't wait on the anon_vma->root->mutex to * serialize against split_huge_page*. */ pmdp_splitting_flush_notify(vma, address, pmd); @@ -1333,7 +1333,7 @@ static int __split_huge_page_map(struct page *page, return ret; } -/* must be called with anon_vma->root->lock hold */ +/* must be called with anon_vma->root->mutex hold */ static void __split_huge_page(struct page *page, struct anon_vma *anon_vma) { diff --git a/mm/mmap.c b/mm/mmap.c index 26efbfca0b20..ac2631b7477f 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2502,15 +2502,15 @@ static void vm_lock_anon_vma(struct mm_struct *mm, struct anon_vma *anon_vma) * The LSB of head.next can't change from under us * because we hold the mm_all_locks_mutex. */ - spin_lock_nest_lock(&anon_vma->root->lock, &mm->mmap_sem); + mutex_lock_nest_lock(&anon_vma->root->mutex, &mm->mmap_sem); /* * We can safely modify head.next after taking the - * anon_vma->root->lock. If some other vma in this mm shares + * anon_vma->root->mutex. If some other vma in this mm shares * the same anon_vma we won't take it again. * * No need of atomic instructions here, head.next * can't change from under us thanks to the - * anon_vma->root->lock. + * anon_vma->root->mutex. */ if (__test_and_set_bit(0, (unsigned long *) &anon_vma->root->head.next)) @@ -2559,7 +2559,7 @@ static void vm_lock_mapping(struct mm_struct *mm, struct address_space *mapping) * vma in this mm is backed by the same anon_vma or address_space. * * We can take all the locks in random order because the VM code - * taking i_mmap_mutex or anon_vma->lock outside the mmap_sem never + * taking i_mmap_mutex or anon_vma->mutex outside the mmap_sem never * takes more than one of them in a row. Secondly we're protected * against a concurrent mm_take_all_locks() by the mm_all_locks_mutex. * @@ -2615,7 +2615,7 @@ static void vm_unlock_anon_vma(struct anon_vma *anon_vma) * * No need of atomic instructions here, head.next * can't change from under us until we release the - * anon_vma->root->lock. + * anon_vma->root->mutex. */ if (!__test_and_clear_bit(0, (unsigned long *) &anon_vma->root->head.next)) diff --git a/mm/rmap.c b/mm/rmap.c index d271845d7d15..ce29d405d093 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -25,7 +25,7 @@ * mm->mmap_sem * page->flags PG_locked (lock_page) * mapping->i_mmap_mutex - * anon_vma->lock + * anon_vma->mutex * mm->page_table_lock or pte_lock * zone->lru_lock (in mark_page_accessed, isolate_lru_page) * swap_lock (in swap_duplicate, swap_info_get) @@ -40,7 +40,7 @@ * * (code doesn't rely on that order so it could be switched around) * ->tasklist_lock - * anon_vma->lock (memory_failure, collect_procs_anon) + * anon_vma->mutex (memory_failure, collect_procs_anon) * pte map lock */ @@ -307,7 +307,7 @@ static void anon_vma_ctor(void *data) { struct anon_vma *anon_vma = data; - spin_lock_init(&anon_vma->lock); + mutex_init(&anon_vma->mutex); atomic_set(&anon_vma->refcount, 0); INIT_LIST_HEAD(&anon_vma->head); } @@ -1143,7 +1143,7 @@ out_mlock: /* * We need mmap_sem locking, Otherwise VM_LOCKED check makes * unstable result and race. Plus, We can't wait here because - * we now hold anon_vma->lock or mapping->i_mmap_mutex. + * we now hold anon_vma->mutex or mapping->i_mmap_mutex. * if trylock failed, the page remain in evictable lru and later * vmscan could retry to move the page to unevictable lru if the * page is actually mlocked.