s390/mm: fix deadlock in unmap_hugepage_range()

git commit cd2934a3 moved the flush_tlb_range() within
__unmap_hugepage_range() inside the mm->page_table_lock, which
triggered a deadlock in s390 tlb flushing code. __tlb_flush_mm_cond()
also tries to acquire the mm->page_table_lock, but that is not needed
because all callers already have mm->mmap_sem or mm->page_table_lock,
so it can be safely removed to fix the deadlock.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Gerald Schaefer 2012-08-30 18:52:54 +02:00 committed by Martin Schwidefsky
parent 5b716ac728
commit d5feaea364

View File

@ -90,12 +90,10 @@ static inline void __tlb_flush_mm(struct mm_struct * mm)
static inline void __tlb_flush_mm_cond(struct mm_struct * mm)
{
spin_lock(&mm->page_table_lock);
if (mm->context.flush_mm) {
__tlb_flush_mm(mm);
mm->context.flush_mm = 0;
}
spin_unlock(&mm->page_table_lock);
}
/*