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b=Aig2rI5LZnBparXKJayH9DfQTyZ7OtOChijgzHA63Cxq3ciD+RFXeJABxz5HkWsv/ Wf1z+yJMHUNVHvbaFPs302gwiDJxJ5yIvtDagpfKEKvv88czg2PsTxs3zV+Y7C7VKg tnHYTXefARKeZ+kLqijMalnofUTETdpDj67H5R8qUb3lmu7IGCZ9qUZwhNs7c3FeUt eZV7D5bNkacFgA024oJx46LUlT7HXEzgaBPxynRp2IslCrPbKL6ct2PFQFNMczpp/G K6K4S5jFSCTir1genN2xE5m1bHPF0TNAu5M+cJcTr7/TqlOgG/J9e0BF56u+tlB2Qw aQY9nenTQvChg== Received: by mail-yw1-f171.google.com with SMTP id 00721157ae682-743ba48eb71so36230607b3.1 for ; Thu, 02 Oct 2025 09:23:37 -0700 (PDT) X-Gm-Message-State: AOJu0YzuaPyjXAaXO1BIGgGwdRZICXNTr1oIL3jGuTL144HMsG+WUoYv DwlVad4bfo4QYUeqgatozJYXYAsSKjEIBCZY7aj4A/dSI7j5+B+UuW8Y0Qe8ltbtGyG5sFXx8OJ xQw/yQ7qcyHxQq7Lj93FeOSpTlaY+gU5ooM8CuBpH0g== X-Google-Smtp-Source: AGHT+IFwNzNeZPmnt5fisak0YY646ClFvwNjheR8H4n6z8Xfh/QhH4uxskxcnFbz9HUNSg2BMUhuxljtM90hW97Ezy4= X-Received: by 2002:a53:cd8a:0:b0:636:fd5:ed0a with SMTP id 956f58d0204a3-63b83b1954dmr3444426d50.16.1759422217090; Thu, 02 Oct 2025 09:23:37 -0700 (PDT) MIME-Version: 1.0 References: <20251001043436.41338-1-bhe@redhat.com> In-Reply-To: From: Chris Li Date: Thu, 2 Oct 2025 09:23:25 -0700 X-Gmail-Original-Message-ID: X-Gm-Features: AS18NWDdSj_DMe1vVCdCPan4hbahezuJV_9PQTJ7X8IR5IPN8dxaZzBkvG3g-Lo Message-ID: Subject: Re: [PATCH 0/3] mm/swap: remove plist swap_active_head To: Baoquan He Cc: linux-mm@kvack.org, akpm@linux-foundation.org, kasong@tencent.com, baohua@kernel.org, nphamcs@gmail.com, shikemeng@huaweicloud.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Stat-Signature: ndb6i5p8fawxgra7kzk8hgmmm5gj8yx9 X-Rspam-User: X-Rspamd-Queue-Id: A296CC0006 X-Rspamd-Server: rspam04 X-HE-Tag: 1759422218-592418 X-HE-Meta: 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 tCiDxmcs oLkfiguXH6//QUPl0pPYigbrr1a9A9lcrFFUhBWptkDASMMdzu6SKb4nlRyyQvtQ2zF2NrWrj/OYwapF4se/1cGIVtBg+B765C2KdTdPwTSJ1s9oqW++4rfZGJas34g8g6t1SrWyHF8LUgMPHRl1yFLkePAW+rAWzYdhK49T3Okgk2MAIir2N52kMC44JCMpj6Z1YvoNuSCob1BAf98MPu/kcQ65lbYuxdi0p9EE7g4xxDi1kczpW1b6I607Kgozpxb9w3lrfl6C0gOWQK3tgHnENDCtqz8PuI0gqGTUg26cDun+xbKYo/Ok/TYD6xEj8E52mhQjLR51zEJwGc4gUJeorbNJofAw1Ee63 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Oct 2, 2025 at 6:09=E2=80=AFAM Baoquan He wrote: > > Can you please clarify what is the benefit of remove plist swap_active_= head? > > e.g. Does it simply the code or make swap code perform better. > > After series "[PATCH v3 0/2] mm/swapfile.c: select the swap device with > default priority round robin", plist swap_active_head is only used in > swapoff api to scan it to find a swap device according to the device > name. It can be replaced with scanning swap_info[], and there's no > efficiency degradation. And we can remove field "struct plist_node > list;" in struct swap_info_struct, and the relevant handling code which > is unnecessary. So the benefit is removing a list. Thank you for confirming that. BTW, I think I found a race bug in your patch 2/3, I replied in the patch email thread. Let me know if that race is valid or not. Chris