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[96.255.20.138]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-4ffb75d7916sm57189031cf.7.2026.01.09.08.08.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 09 Jan 2026 08:08:27 -0800 (PST) Date: Fri, 9 Jan 2026 11:07:52 -0500 From: Gregory Price To: Akinobu Mita Cc: linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, hannes@cmpxchg.org, david@kernel.org, mhocko@kernel.org, zhengqi.arch@bytedance.com, shakeel.butt@linux.dev, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, vbabka@suse.cz, rppt@kernel.org, surenb@google.com, bingjiao@google.com Subject: Re: [PATCH v3 3/3] mm/vmscan: don't demote if there is not enough free memory in the lower memory tier Message-ID: References: <20260108101535.50696-1-akinobu.mita@gmail.com> <20260108101535.50696-4-akinobu.mita@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260108101535.50696-4-akinobu.mita@gmail.com> X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 792D68001C X-Stat-Signature: zpgjbtsw8tgbnytxersh9qfk81egzr1m X-Rspam-User: X-HE-Tag: 1767974909-450115 X-HE-Meta: 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 2ZQKZIyc oPO35O5jG7acdMr0Z3i0DXZmN0py9gDtggXGpkp0sItknNenwKFcKNgZr0W838uQ2OFroU+pU5XrwtVQwifxGYfTStyRNuLyb9aN4/8M8mRPFW7wWVe2SimcdiyM3vUVQA5TV4dbBWpSgqjqVP65Cwc3Ra2ttKnuujJhB/jOGNyTLJxq62Vc2SqyI1XsC2rf74JCW6+uN3/mSU/warzPuLbunx0zNFn2Ygu1sJgsYKlAx0zdfvEzlKmNVlq1ZeVBX+e52y5uVUEy5fWCHAO7FLMM4tuIquVVeAQ/QZSZ/d1xmjuFLpkLEg62buKTI2vR61Tq/pvgIGON3ru/yfLifgpLsdKtnc/ub66o+T4tlZH3DmedFIHj2B0PbINvmtzcMXWAlZhNAFj8e3GBvJW/F+wvIFVJdsk7KqoKw2mz16PXXGck= 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: > + for_each_node_mask(nid, allowed_mask) { > + int z; > + struct zone *zone; > + struct pglist_data *pgdat = NODE_DATA(nid); > + > + for_each_managed_zone_pgdat(zone, pgdat, z, MAX_NR_ZONES - 1) { > + if (zone_watermark_ok(zone, 0, min_wmark_pages(zone), > + ZONE_MOVABLE, 0)) Why does this only check zone movable? Also, would this also limit pressure-signal to invoke reclaim when there is still swap space available? Should demotion not be a pressure source for triggering harder reclaim? ~Gregory