On Thu, Jul 19, 2012 at 09:08:34AM +0000, Cong Wang wrote:
> On Wed, 18 Jul 2012 at 10:43 GMT, Mel Gorman <mgorman@xxxxxxx> wrote:
> > + if (!down_read_trylock(&svma->vm_mm->mmap_sem)) {
> > + mutex_unlock(&mapping->i_mmap_mutex);
> > + goto retry;
> > + }
> > +
> > + smmap_sem = &svma->vm_mm->mmap_sem;
> > + spage_table_lock = &svma->vm_mm->page_table_lock;
> > + spin_lock_nested(spage_table_lock, SINGLE_DEPTH_NESTING);
> >
> > saddr = page_table_shareable(svma, vma, addr, idx);
> > if (saddr) {
> > @@ -85,6 +108,10 @@ static void huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
> > break;
> > }
> > }
> > + up_read(smmap_sem);
> > + spin_unlock(spage_table_lock);
>
> Looks like we should do spin_unlock() before up_read(),
> in the reverse order of how they get accquired.
>
Will fix, thanks for pointing this out.
As an aside, I would prefer if you did not drop people from the CC list. I
would have missed this mail for a long time if it hadn't been pointed out
to me privately.
--
Mel Gorman
SUSE Labs
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>