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Message-Id: <5B921FEE02000078001E6258@prv1-mh.provo.novell.com>
Date:   Fri, 07 Sep 2018 00:51:26 -0600
From:   "Jan Beulich" <JBeulich@suse.com>
To:     "Marek Marczykowski" <marmarek@invisiblethingslab.com>
Cc:     "xen-devel" <xen-devel@lists.xenproject.org>,
        "Boris Ostrovsky" <boris.ostrovsky@oracle.com>,
        "Juergen Gross" <jgross@suse.com>, <linux-kernel@vger.kernel.org>
Subject: Re: [Xen-devel] [PATCH] xen/balloon: add runtime control for
 scrubbing ballooned out pages
References: <20180906153355.25363-1-marmarek@invisiblethingslab.com>
In-Reply-To: <20180906153355.25363-1-marmarek@invisiblethingslab.com>
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>>> On 06.09.18 at 17:33, <marmarek@invisiblethingslab.com> wrote:
> --- a/include/xen/mem-reservation.h
> +++ b/include/xen/mem-reservation.h
> @@ -17,12 +17,17 @@
>  
>  #include <xen/page.h>
>  
> +#ifdef CONFIG_XEN_SCRUB_PAGES
> +extern bool xen_scrub_pages;
> +
>  static inline void xenmem_reservation_scrub_page(struct page *page)
>  {
> -#ifdef CONFIG_XEN_SCRUB_PAGES
> -	clear_highpage(page);
> -#endif
> +	if (xen_scrub_pages)
> +		clear_highpage(page);
>  }
> +#else
> +static inline void xenmem_reservation_scrub_page(struct page *page) { }
> +#endif

Wouldn't CONFIG_XEN_SCRUB_PAGES then better become
CONFIG_XEN_SCRUB_PAGES_DEFAULT, with the value used as
initializer of xen_scrub_pages?

Jan