From mboxrd@z Thu Jan  1 00:00:00 1970
From: Avi Kivity <avi@qumranet.com>
Subject: Re: [PATCH] qemu-kvm: Fix test for I/O thread
Date: Sat, 19 Jul 2008 10:01:23 +0300
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Cc: kvm-devel <kvm@vger.kernel.org>
To: Jan Kiszka <jan.kiszka@siemens.com>
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Jan Kiszka wrote:
> Looks to me like this was rather intended. But given that 4e8b8a6d92c5ece048e65be3a3980d24f065b32b claims to actually fix a bug in
> its original broken form, please have a careful look.
>
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>
> diff --git a/qemu/qemu-kvm.c b/qemu/qemu-kvm.c
> index 431e26d..c36f60f 100644
> --- a/qemu/qemu-kvm.c
> +++ b/qemu/qemu-kvm.c
> @@ -89,7 +89,7 @@ static void qemu_cond_wait(pthread_cond_t *cond)
>      pthread_cond_timedwait(cond, &qemu_mutex, &ts);
>      /* If we're the I/O thread, some other thread may be waiting for aio
>       * completion */
> -    if (!vcpu_info)
> +    if (!env)
>          qemu_aio_poll();
>      cpu_single_env = env;
>  }
>   

Aren't the two lines equivalent?  vcpu_info is a thread-local-storage 
variable, and is unset for the iothread.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.