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From: Avi Kivity <avi@redhat.com>
To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	Anthony Liguori <aliguori@us.ibm.com>,
	qemu-devel <qemu-devel@nongnu.org>,
	Gleb Natapov <gleb@redhat.com>
Subject: Re: [Qemu-devel] [RESEND][PATCH] Replace qemu_system_cond with VCPU stop mechanism
Date: Mon, 22 Aug 2011 19:18:39 +0300	[thread overview]
Message-ID: <4E52815F.6010607@redhat.com> (raw)
In-Reply-To: <4E5279F3.7070103@siemens.com>

On 08/22/2011 06:46 PM, Jan Kiszka wrote:
> We can express the VCPU thread wakeup with the stop mechanism, saving
> both qemu_system_ready and the qemu_system_cond. For KVM threads, we can
> just enter the main loop as long as the thread is stopped. The central
> TCG thread is better held back before the loop as there can be side
> effects of the services called even when all CPUs are stopped.
>
> Creating VCPUs in stopped state will also be required for proper CPU
> hotplugging support.
>
>
> -    /* and wait for machine initialization */
> -    while (!qemu_system_ready) {
> -        qemu_cond_wait(&qemu_system_cond,&qemu_global_mutex);
> +    /* wait for initial kick-off after machine start */
> +    while (!first_cpu->stopped) {
> +        qemu_cond_wait(tcg_halt_cond,&qemu_global_mutex);
>       }

Seems inverted - do we want to wait until first_cpu is stopped, or while 
first_cpu is stopped?

Do we want to process run_on_cpu() events after the machine is created 
but before a cpu is started (if starting with -S)?

-- 
error compiling committee.c: too many arguments to function

  reply	other threads:[~2011-08-22 16:18 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-22 15:46 [Qemu-devel] [RESEND][PATCH] Replace qemu_system_cond with VCPU stop mechanism Jan Kiszka
2011-08-22 16:18 ` Avi Kivity [this message]
2011-08-22 16:35   ` [Qemu-devel] [PATCH v3] " Jan Kiszka
2011-08-22 20:18     ` Anthony Liguori

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