linux-kernel - Re: [PATCH 1/5] mm/vmalloc: query dynamic DEBUG

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Date:	Thu, 4 Feb 2016 09:32:14 +0100
From:	Christian Borntraeger <borntraeger@...ibm.com>
To:	Joonsoo Kim <js1304@...il.com>,
	Andrew Morton <akpm@...ux-foundation.org>
Cc:	David Rientjes <rientjes@...gle.com>, linux-kernel@...r.kernel.org,
	linux-mm@...ck.org,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Takashi Iwai <tiwai@...e.com>,
	Chris Metcalf <cmetcalf@...hip.com>,
	Christoph Lameter <cl@...ux.com>, linux-api@...r.kernel.org,
	Joonsoo Kim <iamjoonsoo.kim@....com>
Subject: Re: [PATCH 1/5] mm/vmalloc: query dynamic DEBUG_PAGEALLOC setting

On 02/04/2016 06:56 AM, Joonsoo Kim wrote:
> We can disable debug_pagealloc processing even if the code is complied
> with CONFIG_DEBUG_PAGEALLOC. This patch changes the code to query
> whether it is enabled or not in runtime.
> 
> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@....com>

Reviewed-by: Christian Borntraeger <borntraeger@...ibm.com>


> ---
>  mm/vmalloc.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index fb42a5b..e0e51bd 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -543,10 +543,10 @@ static void vmap_debug_free_range(unsigned long start, unsigned long end)
>  	 * debugging doesn't do a broadcast TLB flush so it is a lot
>  	 * faster).
>  	 */
> -#ifdef CONFIG_DEBUG_PAGEALLOC
> -	vunmap_page_range(start, end);
> -	flush_tlb_kernel_range(start, end);
> -#endif
> +	if (debug_pagealloc_enabled()) {
> +		vunmap_page_range(start, end);
> +		flush_tlb_kernel_range(start, end);
> +	}
>  }
> 
>  /*
>