From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sasha Levin <levinsasha928@gmail.com>
Subject: Re: [PATCH 1/3] kvm tools: add signal placeholder to avoid balloon
 crash
Date: Thu, 11 Aug 2011 10:29:05 +0300
Message-ID: <1313047745.3456.4.camel@lappy>
References: <1313039267-25951-1-git-send-email-walimisdev@gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Cc: Pekka Enberg <penberg@kernel.org>, Ingo Molnar <mingo@elte.hu>,
	Asias He <asias.hejun@gmail.com>, kvm@vger.kernel.org
To: Liming Wang <walimisdev@gmail.com>
Return-path: <kvm-owner@vger.kernel.org>
Received: from mail-fx0-f46.google.com ([209.85.161.46]:52459 "EHLO
	mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1750802Ab1HKHaG (ORCPT <rfc822;kvm@vger.kernel.org>);
	Thu, 11 Aug 2011 03:30:06 -0400
Received: by fxh19 with SMTP id 19so1485323fxh.19
        for <kvm@vger.kernel.org>; Thu, 11 Aug 2011 00:30:04 -0700 (PDT)
In-Reply-To: <1313039267-25951-1-git-send-email-walimisdev@gmail.com>
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

On Thu, 2011-08-11 at 13:07 +0800, Liming Wang wrote:
> If "kvm run" without balloon option, use "kvm balloon" may
> crash kvm. Add signal placeholder to avoid this.
> 
> Signed-off-by: Liming Wang <walimisdev@gmail.com>
> ---
>  tools/kvm/builtin-run.c |    7 +++++++
>  1 files changed, 7 insertions(+), 0 deletions(-)
> 
> diff --git a/tools/kvm/builtin-run.c b/tools/kvm/builtin-run.c
> index fa5de27..d725834 100644
> --- a/tools/kvm/builtin-run.c
> +++ b/tools/kvm/builtin-run.c
> @@ -280,6 +280,10 @@ static void handle_sigstop(int sig)
>  	kvm_cpu__reboot();
>  }
>  
> +static void handle_empty(int sig)
> +{
> +}
> +
>  static void *kvm_cpu_thread(void *arg)
>  {
>  	current_kvm_cpu		= arg;
> @@ -469,6 +473,9 @@ int kvm_cmd_run(int argc, const char **argv, const char *prefix)
>  	signal(SIGUSR2, handle_sigusr2);
>  	signal(SIGKVMSTOP, handle_sigstop);
>  	signal(SIGKVMRESUME, handle_sigusr2);
> +	/* signal placeholder if not enable balloon */
> +	signal(SIGKVMADDMEM, handle_empty);

You can just do this:
	signal(SIGKVMADDMEM, SIG_IGN);

For both, and avoid the empty handler.

> +	signal(SIGKVMDELMEM, handle_empty);
>  
>  	nr_online_cpus = sysconf(_SC_NPROCESSORS_ONLN);
>  

-- 

Sasha.