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To: Matthew Wilcox , Gregory Price Cc: linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, akpm@linux-foundation.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev, shakeel.butt@linux.dev, Huang Ying , Keith Busch , Feng Tang , Neha Gholkar References: <20250411221111.493193-1-gourry@gourry.net> Content-Language: en-US From: Donet Tom In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: 6dsAiMeB33E3lh-bj9ZwhYx2gUIGJIgE X-Proofpoint-GUID: GELQ2W6CYobMvDj3cE-s1NHetRq3AAmh X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1095,Hydra:6.0.680,FMLib:17.12.68.34 definitions=2025-04-13_02,2025-04-10_01,2024-11-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 clxscore=1011 spamscore=0 impostorscore=0 mlxlogscore=688 lowpriorityscore=0 priorityscore=1501 mlxscore=0 suspectscore=0 bulkscore=0 adultscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2502280000 definitions=main-2504130036 On 4/12/25 5:19 AM, Matthew Wilcox wrote: > On Fri, Apr 11, 2025 at 06:11:05PM -0400, Gregory Price wrote: >> Unmapped page cache pages can be demoted to low-tier memory, but > No. Page cache should never be demoted to low-tier memory. > NACK this patchset. Hi Mathew, I have one doubt. Under memory pressure, page cache allocations can fall back to lower-tier memory, right? So later, if those page cache pages become hot, shouldn't we promote them? Thanks Donet