Messages in this thread | | | Date | Mon, 9 Oct 2017 07:10:01 +0300 | From | "Kirill A. Shutemov" <> | Subject | Re: [BUG] mm/vmalloc: ___might_sleep is called under a spinlock in __purge_vmap_area_lazy |
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On Mon, Oct 09, 2017 at 12:00:33PM +0800, Jia-Ju Bai wrote: > The ___might_sleep is called under a spinlock, and the function call graph > is: > __purge_vmap_area_lazy (acquire the spinlock) > cond_resched_lock > ___might_sleep > > In this situation, ___might_sleep may prints error log message because a > spinlock is held. > A possible fix is to remove ___might_sleep in cond_resched_lock. > > This bug is found by my static analysis tool and my code review.
This analysis doesn't makes sense.
The point of cond_resched_lock() is that it drops the lock, if resched is required.
___might_sleep() is called with preempt_offset equal to PREEMPT_LOCK_OFFSET, so it won't report error if it's the only lock we hold.
-- Kirill A. Shutemov
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