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>
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 0556c6a..e5b2d31 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -738,7 +738,7 @@
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 @@
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 @@
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 @@
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 @@
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 bf86658..0b5a93a 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -382,7 +382,7 @@
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 @@
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 5a6badd..834b2d7 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2724,7 +2724,8 @@
}
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 6738c47..1e4a600 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -161,7 +161,7 @@
* 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 @@
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);