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Date:   Fri, 11 Mar 2022 02:02:06 +0000
In-Reply-To: <20220310092456.GJ15701@techsingularity.net>
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References: <20220310092456.GJ15701@techsingularity.net>
Subject: Re: [PATCH] mm/page_alloc: check high-order pages for corruption
 during PCP operations
From:   Shakeel Butt <shakeelb@google.com>
To:     Mel Gorman <mgorman@techsingularity.net>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Eric Dumazet <edumazet@google.com>,
        Eric Dumazet <eric.dumazet@gmail.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        linux-mm <linux-mm@kvack.org>, Vlastimil Babka <vbabka@suse.cz>,
        Michal Hocko <mhocko@kernel.org>, Wei Xu <weixugc@google.com>,
        Greg Thelen <gthelen@google.com>,
        Hugh Dickins <hughd@google.com>,
        David Rientjes <rientjes@google.com>
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On Thu, Mar 10, 2022 at 09:24:56AM +0000, Mel Gorman wrote:
> Eric Dumazet pointed out that commit 44042b449872 ("mm/page_alloc: allow
> high-order pages to be stored on the per-cpu lists") only checks the head
> page during PCP refill and allocation operations. This was an oversight
> and all pages should be checked. This will incur a small performance
> penalty but it's necessary for correctness.

> Fixes: 44042b449872 ("mm/page_alloc: allow high-order pages to be stored  
> on the per-cpu lists")
> Reported-by: Eric Dumazet <edumazet@google.com>
> Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
> Acked-by: Eric Dumazet <edumazet@google.com>

Reviewed-by: Shakeel Butt <shakeelb@google.com>