From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 44807361977 for ; Fri, 24 Jul 2026 06:10:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784873449; cv=none; b=CtqBb+zjJtXrh1a9FFyg+SJt4VUZAooGnOel7D9eP/NDT6fTBOcJB6cv3+jl8L7OSRw1azDjEVLCyyiw92THEeImhifPFDvdSMGQV4Rn5Y8aZ2PnjU1+itEBU+ry08264qR9wCdsUngyfCQsuu1JquUVAkhQ4xH618QvrJMyC1A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784873449; c=relaxed/simple; bh=J96VFyk9PGn8YyeTGzVOaRpj+S3LUu9gshct9gb/QeQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=I46gfex7Wl2d+krL3UuV0UiLKNgtng/yA8G5smhsxMFpLN4+3MC4UYPfN/W2VGzRVzuk32AHhOBQS5u8d2GyGpyf2aOyQ85UQI5mcArp2zNUbzlwOPVtrZ9fOkpuUKm9cPFmHS/QP6HpU3I0gXEeUU+Lou11S81nal2K4Gtpn+E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=HU/a7MTW; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="HU/a7MTW" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 058041477; Thu, 23 Jul 2026 23:10:42 -0700 (PDT) Received: from [10.164.19.44] (unknown [10.164.19.44]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DCA483F66F; Thu, 23 Jul 2026 23:10:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1784873446; bh=J96VFyk9PGn8YyeTGzVOaRpj+S3LUu9gshct9gb/QeQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=HU/a7MTWgbwkE3Cn0OZG0UUhbr8qMmr+Tpq7RykHBoVU17RtBX2K47oKjYS78Tand uYU406QHXG4sRORMa/qI7Xvc7yLjwhocEVFRj4T7jCv4zOwmg+jSSFkOmgh7hylKcy VMBln1PeS4uylznX5Yn8k0iWLilj/famGa4IywEE= Message-ID: Date: Fri, 24 Jul 2026 11:40:36 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 01/11] mm: add PMD swap entry detection support To: Usama Arif , Andrew Morton , david@kernel.org, chrisl@kernel.org, kasong@tencent.com, ljs@kernel.org, ziy@nvidia.com, linux-mm@kvack.org Cc: ying.huang@linux.alibaba.com, Baoquan He , willy@infradead.org, youngjun.park@lge.com, hannes@cmpxchg.org, riel@surriel.com, shakeel.butt@linux.dev, alex@ghiti.fr, kas@kernel.org, baohua@kernel.org, baolin.wang@linux.alibaba.com, Nico Pache , "Liam R. Howlett" , ryan.roberts@arm.com, Vlastimil Babka , lance.yang@linux.dev, linux-kernel@vger.kernel.org, nphamcs@gmail.com, shikemeng@huaweicloud.com, yosry@kernel.org, kernel-team@meta.com References: <20260722152043.2273289-1-usama.arif@linux.dev> <20260722152043.2273289-2-usama.arif@linux.dev> Content-Language: en-US From: Dev Jain In-Reply-To: <20260722152043.2273289-2-usama.arif@linux.dev> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit [------] > diff --git a/include/linux/leafops.h b/include/linux/leafops.h > index 4c1476ae3234..8397193ba399 100644 > --- a/include/linux/leafops.h > +++ b/include/linux/leafops.h > @@ -102,6 +102,8 @@ static inline softleaf_t softleaf_from_pmd(pmd_t pmd) > pmd = pmd_swp_clear_soft_dirty(pmd); > if (pmd_swp_uffd(pmd)) > pmd = pmd_swp_clear_uffd(pmd); > + if (pmd_swp_exclusive(pmd)) > + pmd = pmd_swp_clear_exclusive(pmd); > arch_entry = __pmd_to_swp_entry(pmd); > > /* Temporary until swp_entry_t eliminated. */ > @@ -634,18 +636,30 @@ static inline bool pmd_is_migration_entry(pmd_t pmd) > */ > static inline bool softleaf_is_valid_pmd_entry(softleaf_t entry) > { > - /* Only device private, migration entries valid for PMD. */ > + /* Device private, migration, and swap entries valid for PMD. */ > return softleaf_is_device_private(entry) || > - softleaf_is_migration(entry); > + softleaf_is_migration(entry) || > + softleaf_is_swap(entry); > +} > + > +/** > + * pmd_is_swap_entry() - Does this PMD entry encode an actual swap entry? > + * @pmd: PMD entry. > + * > + * Returns: true if the PMD encodes a swap entry, otherwise false. > + */ > +static inline bool pmd_is_swap_entry(pmd_t pmd) > +{ > + return softleaf_is_swap(softleaf_from_pmd(pmd)); > } > > /** > * pmd_is_valid_softleaf() - Is this PMD entry a valid softleaf entry? > * @pmd: PMD entry. > * > - * PMD leaf entries are valid only if they are device private or migration > - * entries. This function asserts that a PMD leaf entry is valid in this > - * respect. > + * PMD leaf entries are valid only if they are device private, migration, > + * or swap entries. This function asserts that a PMD leaf entry is valid > + * in this respect. > * > * Returns: true if the PMD entry is a valid leaf entry, otherwise false. > */ > @@ -673,6 +687,8 @@ static inline struct folio *pmd_to_softleaf_folio(pmd_t pmd) Nit: This function really should have been named "softleaf_pmd_to_folio", or "pmd_softleaf_to_folio", perhaps throw in a patch to rename? > VM_WARN_ON_ONCE(true); > return NULL; > } > + if (!softleaf_has_pfn(entry)) > + return NULL; I am guessing that after the later patches add swp support, we should never reach pmd_to_softleaf_folio() with a swap entry, in which case, we could add a WARN_ON_ONCE() here. (didn't check if you have done that later, just writing this here) > return softleaf_to_folio(entry); > } > > diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h > index 8c093c119e5a..e10a7e91e426 100644 > --- a/include/linux/pgtable.h > +++ b/include/linux/pgtable.h > @@ -1917,6 +1917,23 @@ static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd) > } > #endif > > +#ifndef CONFIG_ARCH_HAS_PMD_SOFTLEAVES > +static inline pmd_t pmd_swp_mkexclusive(pmd_t pmd) > +{ > + return pmd; > +} > + > +static inline bool pmd_swp_exclusive(pmd_t pmd) > +{ > + return false; > +} > + > +static inline pmd_t pmd_swp_clear_exclusive(pmd_t pmd) > +{ > + return pmd; > +} > +#endif > + > #ifndef __HAVE_PFNMAP_TRACKING > /* > * Interfaces that can be used by architecture code to keep track of