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From: Muchun Song In-Reply-To: Date: Mon, 3 Aug 2026 14:45:55 +0800 Cc: Muchun Song , Andrew Morton , Oscar Salvador , David Hildenbrand , Vlastimil Babka , Lorenzo Stoakes , Michal Hocko , David Laight , linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Message-Id: <4FB096F3-80EC-4FD3-B859-4AF3162AABB2@linux.dev> References: <20260720093127.540540-1-songmuchun@bytedance.com> <20260720093127.540540-4-songmuchun@bytedance.com> <5005C7D3-B3ED-4C62-B611-8465D2BC69FD@linux.dev> <178540851830.2154539.6359871825839331816.b4-reply@b4> <3FCC8989-95DB-450F-95C3-183787DF4D08@linux.dev> <89878C33-9BCD-4FD7-92A0-884CF682CBF3@linux.dev> To: Mike Rapoport X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 7C79540003 X-Stat-Signature: 4kmfsdq8u3g3fwzc61ky9jy1bpxrs8bk X-HE-Tag: 1785739602-181427 X-HE-Meta: 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 qXf3oenE Sg/RLXdJ5J2qHHnWXdkgH99wRhLuirshCK70uXmPsmv0/Vt3hhEfn44UdSo67ccRpxj4ZvxmtX8+XF3ZCdeA7yDw/deNgZ+PscrNhkccvUYuB+T4WGoCmct8YrQ1772xQIu3bLJsVBrj8bl8r+SVL7Kz9fb6EGoIunGQ2i600NqiYqemQkKby80pU33swrmzamcOPaypbcIQwX0EqLCvT9K2BeDxDCyXCHL2gjDsRizhIlC8l3ZdvsVlxDRN2GyXF1Y41TdPK4ZWmGgEffY+xZADWX8+4Ek446uI29+4Dspi8j+rfopQd4vIsHdHR1+eExe+EWZ5nqoXUggp6voQImegT2/01wPg7Oug+zxcYdT+p/HMz4xeJ3onKlHyY6L0zjGy8 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > On Aug 3, 2026, at 14:38, Mike Rapoport wrote: >=20 > On Fri, Jul 31, 2026 at 10:13:43AM +0800, Muchun Song wrote: >>> On Jul 30, 2026, at 22:32, Mike Rapoport wrote: >>>>=20 >>>> Since we also use __pfn_to_section in the patch 14 in this series = for >>>> !SPARSEMEM, we need to make corresponding = adjustments=E2=80=94specifically, by using >>>> pfn_to_section_order to determine whether the vmemmap of a given = section is >>>> optimizable. This new helper will be called from several places, so = I'm afraid >>>> its introduction is unavoidable. >>>=20 >>> Do you mean that section_vmemmap_optimizable() will receive pfn as a >>> parameter and use pfn_to_section_order() internally? >>=20 >> I was originally planning to go with the this approach, but now I've = come across >> something that feels a bit unusual to me: a function whose name = starts with section >> takes a pfn as its argument instead of a mem_section. >>=20 >> So I started thinking about an alternative. How about we keep = section_vmemmap_optimizable() >> as it is, but introduce a new helper like this: >>=20 >> static inline bool order_vmemmap_optimizable(unsigned int order) >> { >> return order >=3D OPTIMIZABLE_FOLIO_MIN_ORDER; >> } >=20 > Maybe name it vmemmap_optimizable_order() so it'll belong to vmemmap > namespace, order_ can be really a lot of things. Make sense. >=20 > I think it makes sense. Let's see how it fits in the end in the new > version :) I'll update it as soon as possible. Muchun, Thanks. >=20 > --=20 > Sincerely yours, > Mike.