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Date: Wed, 18 Mar 2015 10:32:57 -0400
From: Rik van Riel <riel@redhat.com>
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To: Michal Hocko <mhocko@suse.cz>, Andrew Morton <akpm@linux-foundation.org>
CC: Al Viro <viro@zeniv.linux.org.uk>, Johannes Weiner <hannes@cmpxchg.org>,
        Mel Gorman <mgorman@suse.de>, Neil Brown <neilb@suse.de>,
        Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
        Sage Weil <sage@inktank.com>, Mark Fasheh <mfasheh@suse.com>,
        linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mm: Use GFP_KERNEL allocation for the page cache in page_cache_read
References: <1426687766-518-1-git-send-email-mhocko@suse.cz>
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On 03/18/2015 10:09 AM, Michal Hocko wrote:

> diff --git a/mm/filemap.c b/mm/filemap.c
> index 968cd8e03d2e..26f62ba79f50 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -1752,7 +1752,7 @@ static int page_cache_read(struct file *file, pgoff_t offset)
>  	int ret;
>  
>  	do {
> -		page = page_cache_alloc_cold(mapping);
> +		page = __page_cache_alloc(GFP_KERNEL|__GFP_COLD);
>  		if (!page)
>  			return -ENOMEM;

Won't this break on highmem systems, by failing to
allocate the page cache from highmem, where previously
it would?