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charset=UTF-8 Date: Mon, 05 Oct 2026 16:14:52 -0400 Message-Id: From: "Zi Yan" Subject: Re: [PATCH v8 07/30] x86: mm: add PMD swap-exclusive helpers Cc: , "Baoquan He" , , , , , , , , , , , "Nico Pache" , "Liam R.Howlett" , , "Vlastimil Babka" , , , , , , , , , "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "Dave Hansen" , To: "Usama Arif" , "Andrew Morton" , , , , , X-Mailer: aerc 0.22.0 References: <20261002095503.3585565-1-usama.arif@linux.dev> <20261002095503.3585565-8-usama.arif@linux.dev> In-Reply-To: <20261002095503.3585565-8-usama.arif@linux.dev> X-ClientProxiedBy: BN9PR03CA0481.namprd03.prod.outlook.com (2603:10b6:408:130::6) To IA0PR12MB8374.namprd12.prod.outlook.com (2603:10b6:208:40e::7) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: IA0PR12MB8374:EE_|CY8PR12MB7313:EE_ X-MS-Office365-Filtering-Correlation-Id: f9e40fa8-7ae1-465a-18cc-08df231d518e X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|23010399003|376014|1800799024|7416014|366016|10067099003|4143699003|56012099006|11063799006|18002099003|22082099003; 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assert that, because an exclusive swa= p > PMD would otherwise be pmd_present(). > > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: Borislav Petkov > Cc: Dave Hansen > Cc: x86@kernel.org > Signed-off-by: Usama Arif > Reviewed-by: Kiryl Shutsemau (Meta) > Reviewed-by: David Hildenbrand (Arm) > --- > arch/x86/include/asm/pgtable.h | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) > > diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtabl= e.h > index d551120a7c889..c35dfa6ceda05 100644 > --- a/arch/x86/include/asm/pgtable.h > +++ b/arch/x86/include/asm/pgtable.h > @@ -1525,6 +1525,26 @@ static inline pte_t pte_swp_clear_exclusive(pte_t = pte) > return pte_clear_flags(pte, _PAGE_SWP_EXCLUSIVE); > } > =20 > +#ifdef CONFIG_ARCH_HAS_PMD_SOFTLEAVES > +/* 32-bit aliases this to _PAGE_PSE, making an exclusive swap PMD presen= t. */ Is it better to say? Since the above comment sounds like 32-bit specific, but the actual constraint is about not being _PAGE_PSE. _PAGE_SWP_EXCLUSIVE cannot be _PAGE_PSE, otherwise making an exclusive swap PMD present. > +static_assert(_PAGE_SWP_EXCLUSIVE !=3D _PAGE_PSE); > + > +static inline pmd_t pmd_swp_mkexclusive(pmd_t pmd) > +{ > + return pmd_set_flags(pmd, _PAGE_SWP_EXCLUSIVE); > +} > + > +static inline bool pmd_swp_exclusive(pmd_t pmd) > +{ > + return pmd_flags(pmd) & _PAGE_SWP_EXCLUSIVE; > +} > + > +static inline pmd_t pmd_swp_clear_exclusive(pmd_t pmd) > +{ > + return pmd_clear_flags(pmd, _PAGE_SWP_EXCLUSIVE); > +} > +#endif > + > #ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY > static inline pte_t pte_swp_mksoft_dirty(pte_t pte) > { Otherwise, LGTM. Reviewed-by: Zi Yan ] --=20 Best Regards, Yan, Zi