Messages in this thread | | | Subject | Re: [PATCH] mm: might_sleep warning | From | Pavel Tatashin <> | Date | Tue, 6 Mar 2018 16:48:31 -0500 |
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> That's why page_alloc_init_late() needs spin_lock_irq(). If a CPU is > holding deferred_zone_grow_lock with enabled interrupts and an > interrupt comes in on that CPU and the CPU runs deferred_grow_zone() in > its interrupt handler, we deadlock. > > lockdep knows about this bug and should have reported it. >
I see what you are saying. Yes you are correct, we need spin_lock_irq() in page_alloc_init_late(). I will update the patch. I am not sure why lockdep has not reported it. May be it is initialized after this code is executed?
Thank you, Pavel
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