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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2013-11-14 14:30:48 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-11-15 09:32:14 +0900
commite1f56c89b040134add93f686931cc266541d239a (patch)
tree36efea76d1803cca3e2a7716850d872db70afd8f
parent57c1ffcefb5acb3c8b5f8436c325a6bdbd8e9c78 (diff)
mm: convert mm->nr_ptes to atomic_long_t
With split page table lock for PMD level we can't hold mm->page_table_lock while updating nr_ptes. Let's convert it to atomic_long_t to avoid races. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Alex Thorlton <athorlton@sgi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/proc/task_mmu.c3
-rw-r--r--include/linux/mm_types.h2
-rw-r--r--kernel/fork.c2
-rw-r--r--mm/huge_memory.c10
-rw-r--r--mm/memory.c4
-rw-r--r--mm/mmap.c3
-rw-r--r--mm/oom_kill.c6
7 files changed, 16 insertions, 14 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index abbe825d20f..8faaebdc6b0 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -62,7 +62,8 @@ void task_mem(struct seq_file *m, struct mm_struct *mm)
total_rss << (PAGE_SHIFT-10),
data << (PAGE_SHIFT-10),
mm->stack_vm << (PAGE_SHIFT-10), text, lib,
- (PTRS_PER_PTE*sizeof(pte_t)*mm->nr_ptes) >> 10,
+ (PTRS_PER_PTE * sizeof(pte_t) *
+ atomic_long_read(&mm->nr_ptes)) >> 10,
swap << (PAGE_SHIFT-10));
}
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index f1ff66dfa79..566df579c51 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -339,6 +339,7 @@ struct mm_struct {
pgd_t * pgd;
atomic_t mm_users; /* How many users with user space? */
atomic_t mm_count; /* How many references to "struct mm_struct" (users count as 1) */
+ atomic_long_t nr_ptes; /* Page table pages */
int map_count; /* number of VMAs */
spinlock_t page_table_lock; /* Protects page tables and some counters */
@@ -360,7 +361,6 @@ struct mm_struct {
unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE */
unsigned long stack_vm; /* VM_GROWSUP/DOWN */
unsigned long def_flags;
- unsigned long nr_ptes; /* Page table pages */
unsigned long start_code, end_code, start_data, end_data;
unsigned long start_brk, brk, start_stack;
unsigned long arg_start, arg_end, env_start, env_end;
diff --git a/kernel/fork.c b/kernel/fork.c
index f6d11fc67f7..e2520756e00 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -532,7 +532,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p)
mm->flags = (current->mm) ?
(current->mm->flags & MMF_INIT_MASK) : default_dump_filter;
mm->core_state = NULL;
- mm->nr_ptes = 0;
+ atomic_long_set(&mm->nr_ptes, 0);
memset(&mm->rss_stat, 0, sizeof(mm->rss_stat));
spin_lock_init(&mm->page_table_lock);
mm_init_aio(mm);
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 0556c6a4495..e5b2d316be2 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -738,7 +738,7 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm,
pgtable_trans_huge_deposit(mm, pmd, pgtable);
set_pmd_at(mm, haddr, pmd, entry);
add_mm_counter(mm, MM_ANONPAGES, HPAGE_PMD_NR);
- mm->nr_ptes++;
+ atomic_long_inc(&mm->nr_ptes);
spin_unlock(&mm->page_table_lock);
}
@@ -771,7 +771,7 @@ static bool set_huge_zero_page(pgtable_t pgtable, struct mm_struct *mm,
entry = pmd_mkhuge(entry);
pgtable_trans_huge_deposit(mm, pmd, pgtable);
set_pmd_at(mm, haddr, pmd, entry);
- mm->nr_ptes++;
+ atomic_long_inc(&mm->nr_ptes);
return true;
}
@@ -896,7 +896,7 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
pmd = pmd_mkold(pmd_wrprotect(pmd));
pgtable_trans_huge_deposit(dst_mm, dst_pmd, pgtable);
set_pmd_at(dst_mm, addr, dst_pmd, pmd);
- dst_mm->nr_ptes++;
+ atomic_long_inc(&dst_mm->nr_ptes);
ret = 0;
out_unlock:
@@ -1392,7 +1392,7 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
tlb_remove_pmd_tlb_entry(tlb, pmd, addr);
pgtable = pgtable_trans_huge_withdraw(tlb->mm, pmd);
if (is_huge_zero_pmd(orig_pmd)) {
- tlb->mm->nr_ptes--;
+ atomic_long_dec(&tlb->mm->nr_ptes);
spin_unlock(&tlb->mm->page_table_lock);
put_huge_zero_page();
} else {
@@ -1401,7 +1401,7 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
VM_BUG_ON(page_mapcount(page) < 0);
add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR);
VM_BUG_ON(!PageHead(page));
- tlb->mm->nr_ptes--;
+ atomic_long_dec(&tlb->mm->nr_ptes);
spin_unlock(&tlb->mm->page_table_lock);
tlb_remove_page(tlb, page);
}
diff --git a/mm/memory.c b/mm/memory.c
index bf8665849a5..0b5a93a49f2 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -382,7 +382,7 @@ static void free_pte_range(struct mmu_gather *tlb, pmd_t *pmd,
pgtable_t token = pmd_pgtable(*pmd);
pmd_clear(pmd);
pte_free_tlb(tlb, token, addr);
- tlb->mm->nr_ptes--;
+ atomic_long_dec(&tlb->mm->nr_ptes);
}
static inline void free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
@@ -573,7 +573,7 @@ int __pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
spin_lock(&mm->page_table_lock);
wait_split_huge_page = 0;
if (likely(pmd_none(*pmd))) { /* Has another populated it ? */
- mm->nr_ptes++;
+ atomic_long_inc(&mm->nr_ptes);
pmd_populate(mm, pmd, new);
new = NULL;
} else if (unlikely(pmd_trans_splitting(*pmd)))
diff --git a/mm/mmap.c b/mm/mmap.c
index 5a6baddde15..834b2d785f1 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2724,7 +2724,8 @@ void exit_mmap(struct mm_struct *mm)
}
vm_unacct_memory(nr_accounted);
- WARN_ON(mm->nr_ptes > (FIRST_USER_ADDRESS+PMD_SIZE-1)>>PMD_SHIFT);
+ WARN_ON(atomic_long_read(&mm->nr_ptes) >
+ (FIRST_USER_ADDRESS+PMD_SIZE-1)>>PMD_SHIFT);
}
/* Insert vm structure into process list sorted by address
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 6738c47f1f7..1e4a600a616 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -161,7 +161,7 @@ unsigned long oom_badness(struct task_struct *p, struct mem_cgroup *memcg,
* The baseline for the badness score is the proportion of RAM that each
* task's rss, pagetable and swap space use.
*/
- points = get_mm_rss(p->mm) + p->mm->nr_ptes +
+ points = get_mm_rss(p->mm) + atomic_long_read(&p->mm->nr_ptes) +
get_mm_counter(p->mm, MM_SWAPENTS);
task_unlock(p);
@@ -364,10 +364,10 @@ static void dump_tasks(const struct mem_cgroup *memcg, const nodemask_t *nodemas
continue;
}
- pr_info("[%5d] %5d %5d %8lu %8lu %7lu %8lu %5hd %s\n",
+ pr_info("[%5d] %5d %5d %8lu %8lu %7ld %8lu %5hd %s\n",
task->pid, from_kuid(&init_user_ns, task_uid(task)),
task->tgid, task->mm->total_vm, get_mm_rss(task->mm),
- task->mm->nr_ptes,
+ atomic_long_read(&task->mm->nr_ptes),
get_mm_counter(task->mm, MM_SWAPENTS),
task->signal->oom_score_adj, task->comm);
task_unlock(task);