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dmarc=pass (policy=quarantine) header.from=vmware.com; spf=none (imf24.hostedemail.com: domain of namit@vmware.com has no SPF policy when checking 52.101.64.11) smtp.mailfrom=namit@vmware.com; arc=pass ("microsoft.com:s=arcselector9901:i=1") X-Rspamd-Server: rspam12 X-Rspam-User: X-Stat-Signature: 1coqd1t4b348woc9g34k91j4b476qikf X-HE-Tag: 1658340571-433380 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000001, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Jul 20, 2022, at 11:00 AM, David Hildenbrand wrote: > My patch review skills have seen better days. I thought you'd be > removing the pte_write() check ... :( Tired eyes ... >=20 >> Having said that, I do notice now that pte_mkdirty() should not be done >> only this condition is fulfilled. Instead we should just have >> something like: >>=20 >> if (will_need) { >> ptent =3D pte_mkyoung(ptent); >> if (pte_write(ptent)) >> ptent =3D pte_mkdirty(ptent); >> } >=20 > As can_change_pte_writable() will fail if it stumbles over a !pte_dirty > page in current code ... so I assume you would have that code before the > actual pte_mkwrite() logic, correct? No, I thought this should go after for 2 reasons: 1. You want to allow the PTE to be made writable following the can_change_pte_writable(). 2. You do not want to set a non-writable PTE as dirty, especially since it might then be used to determine that the PTE can become writable. Doing so would circumvent cases in which set_page_dirty() needs to be called and break things down.