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Date: Wed, 31 May 2017 18:04:23 +0200
From: Michal Hocko <mhocko@kernel.org>
To: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>
Subject: strange PAGE_ALLOC_COSTLY_ORDER usage in xgbe_map_rx_buffer
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Hi Tom,
I have stumbled over the following construct in xgbe_map_rx_buffer
	order = max_t(int, PAGE_ALLOC_COSTLY_ORDER - 1, 0);
which looks quite suspicious. Why does it PAGE_ALLOC_COSTLY_ORDER - 1?
And why do you depend on PAGE_ALLOC_COSTLY_ORDER at all?

Thanks!
-- 
Michal Hocko
SUSE Labs