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Thu, 09 Apr 2026 09:17:42 -0700 (PDT) X-Received: by 2002:a05:690e:11cd:b0:64e:e0fc:a311 with SMTP id 956f58d0204a3-650488b2a89mr24106105d50.66.1775751459745; Thu, 09 Apr 2026 09:17:39 -0700 (PDT) MIME-Version: 1.0 References: <20260226031741.230674-1-npache@redhat.com> <20260226032347.232939-1-npache@redhat.com> <8a4568de-e0f9-471b-bc94-1062d4af3938@kernel.org> <2e3f7c8c-c443-4e71-ad60-36c5203de09b@kernel.org> In-Reply-To: <2e3f7c8c-c443-4e71-ad60-36c5203de09b@kernel.org> From: Nico Pache Date: Thu, 9 Apr 2026 10:17:27 -0600 X-Gm-Features: AQROBzDa3ZlDSyBeTiJ6U3kFPCzeIQ0iT24eqWDzIWH0VQcWacDEzklP5yv7TuM Message-ID: Subject: Re: [PATCH mm-unstable v15 03/13] mm/khugepaged: generalize __collapse_huge_page_* for mTHP support To: "David Hildenbrand (Arm)" Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, aarcange@redhat.com, akpm@linux-foundation.org, anshuman.khandual@arm.com, apopple@nvidia.com, baohua@kernel.org, baolin.wang@linux.alibaba.com, byungchul@sk.com, catalin.marinas@arm.com, cl@gentwo.org, corbet@lwn.net, dave.hansen@linux.intel.com, dev.jain@arm.com, gourry@gourry.net, hannes@cmpxchg.org, hughd@google.com, jack@suse.cz, jackmanb@google.com, jannh@google.com, jglisse@google.com, joshua.hahnjy@gmail.com, kas@kernel.org, lance.yang@linux.dev, Liam.Howlett@oracle.com, lorenzo.stoakes@oracle.com, mathieu.desnoyers@efficios.com, matthew.brost@intel.com, mhiramat@kernel.org, mhocko@suse.com, peterx@redhat.com, pfalcato@suse.de, rakie.kim@sk.com, raquini@redhat.com, rdunlap@infradead.org, richard.weiyang@gmail.com, rientjes@google.com, rostedt@goodmis.org, rppt@kernel.org, ryan.roberts@arm.com, shivankg@amd.com, sunnanyong@huawei.com, surenb@google.com, thomas.hellstrom@linux.intel.com, tiwai@suse.de, usamaarif642@gmail.com, vbabka@suse.cz, vishal.moola@gmail.com, wangkefeng.wang@huawei.com, will@kernel.org, willy@infradead.org, yang@os.amperecomputing.com, ying.huang@linux.alibaba.com, ziy@nvidia.com, zokeefe@google.com X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: mjc1Sb8lJNUBjyDB2WEAbeP-5KRRXrZIe5PJKR22rrU_1775751463 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: A977040018 X-Stat-Signature: ea8iobqh7dcxg6t4o1ty9mqogc84uazk X-Rspam-User: X-Rspamd-Server: rspam07 X-HE-Tag: 1775751465-507466 X-HE-Meta: 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 UWRJE+S/ g870ciM1LTmq2Ey/Cuho5Sa4luJsCVlV2rgxa6eR8JSCqAOmcd7rN6MemU+Wl6TLvi3LDJcUbbwqQkneA+km7lIejT/RiVq4cH3fXJWR6/4WtOWa6JOT6D2SxiCUfDF6q4iZU8NxQ5d1eD0Gok8EzFwchRCT/gdYtJzTOUwL/Ksh2ZEpR3LeeLFycIuhIVSyp/gONFjppGV/fJszDOWwOFCo2OMn408AsHLmVAXJBhcpGNl261C05MbkFuVFpZALs3aKbCetlGMwMIdl5fcaLkULv3fhW7RRj9bW+WRupIbUkUQcVmDLCiN2O72vmNK8MFGtfUHVENSyeFUfkpRfJVksLzrNL5AZFQgjTPQ7BjiquFMuE2uQplA/NJeUbZpoSzGLeOV+xysTHSFwgKDCZFEh9xkBcJjV9zKZaLe96/46eOK+uhTj0+/5fp4ZAyrYN4eJe Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Apr 9, 2026 at 2:14=E2=80=AFAM David Hildenbrand (Arm) wrote: > > On 4/8/26 21:48, Nico Pache wrote: > > On Thu, Mar 12, 2026 at 2:56=E2=80=AFPM David Hildenbrand (Arm) > > wrote: > >> > >> On 3/12/26 21:36, David Hildenbrand (Arm) wrote: > >>> > >>> Okay, now I am confused. Why are you not taking care of > >>> collapse_scan_pmd() in the same context? > >>> > >>> Because if you make sure that we properly check against a max_ptes_sw= ap > >>> similar as in the style above, we'd rule out swapin right from the st= art? > >>> > >>> Also, I would expect that all other parameters in there are similarly > >>> handled? > >>> > >> > >> Okay, I think you should add the following: > > > > Hey! Thanks for all your reviews here. > > > > For multiple reasons, here is the solution I developed: > > > > Add a patch before the generalize __collapse.. patch that reworks the > > max_ptes* handling and introduces the helpers (no functional changes). > > I assume that's roughly the patch I shared below? If so, sounds good to m= e. Ok cool! Yeah very similar. I was just making sure you weren't dead set on it being squashed into the other patch. > > -- > Cheers, > > David >