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Wed, 06 May 2026 08:22:41 -0700 (PDT) Received: from gourry-fedora-PF4VCD3F ([185.194.185.26]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-45054b02802sm13350178f8f.17.2026.05.06.08.22.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 06 May 2026 08:22:40 -0700 (PDT) Date: Wed, 6 May 2026 16:22:34 +0100 From: Gregory Price To: Matthew Wilcox Cc: Bharata B Rao , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Jonathan.Cameron@huawei.com, dave.hansen@intel.com, mgorman@techsingularity.net, mingo@redhat.com, peterz@infradead.org, raghavendra.kt@amd.com, riel@surriel.com, rientjes@google.com, sj@kernel.org, weixugc@google.com, ying.huang@linux.alibaba.com, ziy@nvidia.com, dave@stgolabs.net, nifan.cxl@gmail.com, xuezhengchu@huawei.com, yiannis@zptcorp.com, akpm@linux-foundation.org, david@kernel.org, byungchul@sk.com, kinseyho@google.com, joshua.hahnjy@gmail.com, yuanchu@google.com, balbirs@nvidia.com, alok.rathore@samsung.com, shivankg@amd.com, donettom@linux.ibm.com Subject: Re: [PATCH v7 0/7] mm: Hot page tracking and promotion infrastructure Message-ID: References: <20260504060924.344313-1-bharata@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 2F43E14000F X-Stat-Signature: qru77ido3s5px57rnpn8bkbmcx9yc9ya X-Rspam-User: X-HE-Tag: 1778080962-61198 X-HE-Meta: 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 9UaO4woY cveLt1f7RoQQ0+fYeOw99JyWa9g5pQKmLv4F31vhKAk2ldxIU+BnoFZp8wjqhGZAKzLb+eyakB/CcPB44kNl1KE5tgQHuIbgQtaeZxPyhaGDlENvfiIkdYItDINpnZOsWXwRZ6k5c6uJ+ps8YCrU46fuuhdz++fdxnHRxlfWF0fNavOfI8hM4R+EjRi6Ljs1ymYxpHush2Xl5/cd3CyyPKQpoS3R/b9XcHZv4wWBi72hRElZxHRQgwBcrmbSO18aOQCgOedfxwO7wmVXq9ojIXfswcR9rBCxDV+NKQzLXW5R8Up0cKrns0wbP56/cwVTmYpe60orIzqPVa1E5P69W+qrCvqmfGgCW+2+z4I/pOEnDfukLpMlvid8F51EJwhTkuQKDjXMBDWuy8VJPfm40En0xGw3SBbrKY1qQVoin9M2UHfySwko8igXqlFyJJazL5fOcsyK83hkJPh8= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, May 04, 2026 at 09:36:05PM +0100, Matthew Wilcox wrote: > On Mon, May 04, 2026 at 11:39:17AM +0530, Bharata B Rao wrote: > > This is v7 of pghot, a hot-page tracking and promotion subsystem. The > > I continue to think we should not do this. My only pushback on the general "we should not do this" is that we need something to counter-balance the demotion bit in vmscan.c, and the current implementation (prot_none faults) is rather :[ I think this series needs to greatly limit its complexity and provide some gentle correction for LRU inversions, and I think they're making a decent attempt at that. But then I think local memory expansion on CXL is going pretty swimmingly in our datacenters :], others may not feel the same. ~Gregory