linux-kernel - Re: [PATCH] mm, x86: Do not zero hugetlbfs pages at boot. -v2

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Date:	Wed, 3 Apr 2013 16:00:49 +0200
From:	Michal Hocko <mhocko@...e.cz>
To:	Robin Holt <holt@....com>
Cc:	Cliff Wickman <cpw@....com>, linux-kernel@...r.kernel.org,
	linux-mm@...ck.org, x86@...nel.org, wli@...omorphy.com
Subject: Re: [PATCH] mm, x86: Do not zero hugetlbfs pages at boot. -v2

On Tue 02-04-13 21:43:44, Robin Holt wrote:
[...]
> diff --git a/mm/bootmem.c b/mm/bootmem.c
> index 2b0bcb0..b2e4027 100644
> --- a/mm/bootmem.c
> +++ b/mm/bootmem.c
> @@ -705,12 +705,16 @@ void * __init __alloc_bootmem(unsigned long size, unsigned long align,
>  
>  void * __init ___alloc_bootmem_node_nopanic(pg_data_t *pgdat,
>  				unsigned long size, unsigned long align,
> -				unsigned long goal, unsigned long limit)
> +				unsigned long goal, unsigned long limit,
> +				int zeroed)
>  {
>  	void *ptr;
>  
>  	if (WARN_ON_ONCE(slab_is_available()))
> -		return kzalloc(size, GFP_NOWAIT);
> +		if (zeroed)
> +			return kzalloc(size, GFP_NOWAIT);
> +		else
> +			return kmalloc(size, GFP_NOWAIT);
>  again:
>  
>  	/* do not panic in alloc_bootmem_bdata() */

You need to update alloc_bootmem_bdata and alloc_bootmem_core as well.
Otherwise this is a no-op for early allocations when slab is not
available which is the case unless something is broken.

[...]
-- 
Michal Hocko
SUSE Labs
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