Re: [PATCH] kvm: fix waitqueue_active without memory barrier invirt/kvm/async_pf.c

From: Kosuke Tatsukawa
Date: Fri Oct 09 2015 - 08:22:38 EST


Paolo Bonzini wrote:
> On 09/10/2015 11:04, Kosuke Tatsukawa wrote:
>> smp_store_mb() called from set_current_state(), which is called from
>> prepare_to_wait() should prevent reordering such as below from
>> happening. wait_event*() also calls set_current_state() inside.
>
> Ah, I missed that set_current_state has a memory barrier in it. The
> patch is okay, but please expand the comment to say that this memory
> barrier pairs with prepare_to_wait's set_current_state().

thank you for the comment. I'll send a new version of the patch with
the modification.
---
Kosuke TATSUKAWA | 3rd IT Platform Department
| IT Platform Division, NEC Corporation
| tatsu@xxxxxxxxxxxxx
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