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b=ObpUvS/1h53cRhwToUg+KuY1S1sDcKEi6lQ1vDdSsqewqK3p16cwpfaU7wgI0T05n k4qaRi29y8dHZ04BlnQE7FFiB81UGsvmJh1CAaEJGTpwdeTHi3SN4F4Je6za9BygpO gbywqJg0pULgoRF47vYPlpXKvtxP9xmZlBk3zRmIt+8J6lgQvnXD2X/RQz98PAxPua sOAuvRPQvuLomfjWor8vxkI0g/DjFuOpP1mGWSkAYy9kYGcgw1bl1n2nMURqZKtHJG hD9esQ+UjEX30hd5FCaH8I4yDwS2bzn/JeqGwEZLPXGXp4mDwZzcSWqtCrlCKunxJR sf1fdrpE/zn6w== Received: by mail-yb1-f178.google.com with SMTP id 3f1490d57ef6-eab80c807faso19339276.0 for ; Wed, 24 Sep 2025 09:06:46 -0700 (PDT) X-Gm-Message-State: AOJu0Yw8b/U8zkb3Tx4q5SMnc48P637xAl55is8az7aSf/7fAHjo5kSK ygU+MuyXz/eeffEBxE53OiRAxjZynBsIWmTrd9y9dGvjtPDB6D87+dK1AeaoaCNk3KU+O5n/7kC vuEVlYRtI1v7OA+4Y/9scmjhFuWED1a9fwDLBDYtP5g== X-Google-Smtp-Source: AGHT+IHqKZlm1trREiFcQiaAKS7sS2A4t7jUJOSiYu27jhmcn/rYdop1uZLDoymAuUw1IsBcxln/2QoAQWVsh4OyWrI= X-Received: by 2002:a05:6902:70c:b0:eac:6cb6:acf8 with SMTP id 3f1490d57ef6-eb37fd2c9d3mr519636276.44.1758730002208; Wed, 24 Sep 2025 09:06:42 -0700 (PDT) MIME-Version: 1.0 References: <20250924091746.146461-1-bhe@redhat.com> In-Reply-To: From: Chris Li Date: Wed, 24 Sep 2025 09:06:30 -0700 X-Gmail-Original-Message-ID: X-Gm-Features: AS18NWBn16TShQnS4kwcp2wpgwJl1jUSrVhE_Nk7t1L2ZjcsvgGAGJZyieqPiwM Message-ID: Subject: Re: [PATCH] mm/swapfile.c: select the swap device with default priority round robin To: Baoquan He Cc: linux-mm@kvack.org, akpm@linux-foundation.org, kasong@tencent.com, baohua@kernel.org, shikemeng@huaweicloud.com, nphamcs@gmail.com, YoungJun Park , Aaron Lu Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 9E9CA20009 X-Rspam-User: X-Rspamd-Server: rspam07 X-Stat-Signature: 4pz1tjdnubw97ho3r3gnkpqy5sfwwh89 X-HE-Tag: 1758730007-189593 X-HE-Meta: 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 aYZhDtDY 7/nU5XXaBBHUwgJPH5DZloFlm9xyNs7H7wwfgxZutHJyNjc0q3X9hBo2raXk5IwnQR1fI9BMUP9vl+5iWxfUSduUY++ap7+1bQLJbbfQnvDU/J/SX64NJrT9rSu9Am64QMIQk2GSkM9RzwYQSfve7sHjTbs78NV/QQXvCDEyUZEeEI4Oe2tTqOtar9yw+xN5nf8iAQmSPV8WB5zVMEYGvhbc2b3VSAjWdz8ZXQwZbvYesRUu2eIV1OVT6Xl62ZWstmznNCtFQShrH1Ox+qSfiTNKh5pYppMAGzLPui9AJb3U2osBE1XUzrzohTJmQTOrT5We8pNN6w1DDMug= 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 Wed, Sep 24, 2025 at 8:54=E2=80=AFAM Chris Li wrote: > > Hi Baoquan, > > Very exciting numbers. I have always suspected the per node priority > is not doing much contribution in the new swap allocator world. I did > not expect it to have negative contributions. > > On Wed, Sep 24, 2025 at 2:18=E2=80=AFAM Baoquan He wrote= : > > > > Currently, on system with multiple swap devices, swap allocation will > > select one swap device according to priority. The swap device with the > > highest priority will be chosen to allocate firstly. > > > > People can specify a priority from 0 to 32767 when swapon a swap device= , > > or the system will set it from -2 then downwards by default. Meanwhile, > > on NUMA system, the swap device with node_id will be considered first > > on that NUMA node of the node_id. > > That behavior was introduced by: a2468cc9bfdf ("swap: choose swap > device according to numa node") BTW, I noticed you did not CC Aaron Lu who introduced a2468cc9bfdf. I CC him here and give him a chance to test it in his environment to defend his patch. Please CC him on the next version if his email does not bounce. Chris