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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 X-Rspam-User: X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 898DD100002 X-Stat-Signature: zbcx93g3ebfr3tagmzja1t9or3ot5uaf X-HE-Tag: 1744521856-586295 X-HE-Meta: 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 oB3V6h0j 447erclbT4VphKyEwWonnGtuB0+L6I5tiMwqr0qnor40v3F6hNzPkKchv+SnYDoS6FOA67f+NOkQFtowYWsxkZ73bLvSfRK0WXLNff067XTYjMMl6CpSH/IJAdO7JE+R71yFFu1oBKykqYO5ScCjMSd8d8kCDaIr0z16Q8Bbmr5rmgqw6QL5qDnS5wNHDE4g68VoIFGelkLQsVA5cLH4obRyNmZtU4CqzsTzw3lygjxsGPe3YJg/yOf1r4wvniLpNmXUEnoga8nCqKGE+jje0czegygQFymdjH87CS7sKE30KSiPpf/GZZj+Hnsc8uxZQAh9K 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 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