Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <c2226813-0aca-0597-a728-95792cbd3ff0@suse.cz>
Date:   Mon, 29 May 2023 19:12:58 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.11.2
Subject: Re: [PATCH 5/5] mm: compaction: drop redundant watermark check in
 compaction_zonelist_suitable()
Content-Language: en-US
To:     Johannes Weiner <hannes@cmpxchg.org>,
        Andrew Morton <akpm@linux-foundation.org>
Cc:     Mel Gorman <mgorman@techsingularity.net>,
        Michal Hocko <mhocko@suse.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, kernel-team@fb.com
References: <20230519123959.77335-1-hannes@cmpxchg.org>
 <20230519123959.77335-6-hannes@cmpxchg.org>
From:   Vlastimil Babka <vbabka@suse.cz>
In-Reply-To: <20230519123959.77335-6-hannes@cmpxchg.org>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 5/19/23 14:39, Johannes Weiner wrote:
> The watermark check in compaction_zonelist_suitable(), called from
> should_compact_retry(), is sandwiched between two watermark checks
> already: before, there are freelist attempts as part of direct reclaim
> and direct compaction; after, there is a last-minute freelist attempt
> in __alloc_pages_may_oom().
> 
> The check in compaction_zonelist_suitable() isn't necessary. Kill it.
> 
> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>

Acked-by: Vlastimil Babka <vbabka@suse.cz>