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b=P+DY3/BCEBZzRZtbE52GFIAtKo1zeDJvzp4GMY0SymOe6AJgpPQdfX5ktQepYtqgQ 07DhZVeFK3U0nNwY3kswiPXQ9KMRRiILoiweLuIltMRr3GgupHTG2MBlwHjuo4dyeA uBI0De6byfQAVexGT4k206x4knGJ0YKPxRC5tFPO3TD3FZLwq/7hXRTQhfIF2PpwZX RrxBv5x2xTEMP74xsFCjCeq2A67rGbhY6QGfjHT2iBGPres6PNrUbCme2WhDGqe1zZ oVDvddpK+3yxpRcktB3tfmnPecjszPDWgBERs1WrIzmgMKruHciUeJm839zQ4kqouj 1jVs0Dh6475zg== Date: Thu, 11 Jun 2026 13:15:58 +0100 From: Lorenzo Stoakes To: Baolin Wang Cc: akpm@linux-foundation.org, david@kernel.org, hughd@google.com, willy@infradead.org, ziy@nvidia.com, liam@infradead.org, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH v2 00/11] add shmem mTHP collapse support Message-ID: References: <47f472ac-0b07-4ffa-a3d4-04fba621252f@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <47f472ac-0b07-4ffa-a3d4-04fba621252f@linux.alibaba.com> X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: EFD2F8000F X-Stat-Signature: bo83tf1aujk9138hqmr8jb63piahgudd X-Rspam-User: X-HE-Tag: 1781180166-483914 X-HE-Meta: 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 cdv2vZAg tBftOmJEHtZm6VXdamNHc/sj5U5b/pFl5B6EswPNpmagIzeD+bFuVUgc1QKlU+zc3rX2LCpeR1fhA8AQMaxv/sGdAkTj4kHVfOml7XRGa88n/Qitb0Gb3JT4qGkGh3qB5PQr/0HhTvA02gF6JFG3gJ8hKM5Nt5ZFwIB342oyoFZsuafPhRgc2nrpURLSdJGAjp+AW9D56FjbStx5AozYk3DGSZ7V3aXPznpq0xgZTLDaWW0ybNeQ0dYvWcIBZVbnV8XBVXkM+b0HX6Yda/KCsGsP4tw== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Jun 11, 2026 at 07:46:55PM +0800, Baolin Wang wrote: > Hi Lorenzo, > > On 6/11/26 2:18 PM, Lorenzo Stoakes wrote: > > On Wed, Jun 10, 2026 at 06:29:08PM +0800, Baolin Wang wrote: > > > (Note: this patchset is not targeting v7.2, but posted for early feedback.) > > > > Hi Baolin, > > > > Speaking broadly, and to repeat what I said to Nico - I'd like to > > re-emphasise my _strong_ desire for us to pay down technical debt in THP > > code before adding any further major features. > > > > Really I'd have liked to see us do this _before_ khugepaged mTHP, but I > > didn't want to put Nico through more than he already endured with that > > series :) > > > > So I'd really like to see some action on that before we embark on any > > further significant changes. > > > > This is no comment on your changes, just something that we really need to > > address in THP generally. > > > > Will try to give some detailed commentary on the actual changes when I have > > time also :) > > I fully understand the current state of THP maintenance, which is why this > is an RFC. I’m not expecting it to be merged into mainline quickly (but > thanks to Lance for the comments). Ack, well maybe you'd be surprised if I didn't mention it ;) And I will try to have a look through on basis of the technical changes! > > Also, as Nico noted, it might be worth reviewing the mTHP collapse selftests > in this series firstly? as they can help validate the anonymous mTHP > collapse path for future changes. Yeah that sounds like a plan and thank you for writing them :) more testing is welcome and very much appreciated. Cheers, Lorenzo