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 479C423312B for ; Thu, 6 Feb 2025 10:55:11 +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=1738839314; cv=none; b=JBOZj6SLfuIXIXdWLYenrUORJw3qAo6qyaLw44/C4s/KfCSDmGwVAH0pxq5376epnIarZP4H8PtPF+ekXMMUKw2rBqYzZZoh7udE7ypOkgEue9lpaE2paKnyaDoY6wXyHlWh8R5hdn+Y8RBOS7EdcZyL/evhM8QS467qUcaUyok= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738839314; c=relaxed/simple; bh=jMcGVCI1J6kvORZQree7+zQxH4uuJbEvuZOH9DPiaXg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=nbTiMipCQ4+1eZeT0/vZnFR+ybY6fLhw3P+Sg6naCGNyxCaedVaRK8XgH/Kjb+4WbwVbd6RocZj1UxYO4E/BCO70GLiL2d56gjN1eNp8XsmTm2nwMfrgG4NGqB7rptRiqCm9Upfn0f4wlURHVRRhv1xIEklTNzypciWErbEPtg8= 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; 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 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 C1D9712FC; Thu, 6 Feb 2025 02:55:34 -0800 (PST) Received: from [10.163.34.115] (unknown [10.163.34.115]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7D6723F5A1; Thu, 6 Feb 2025 02:55:06 -0800 (PST) Message-ID: Date: Thu, 6 Feb 2025 16:25:04 +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 v1 05/16] mm/page_table_check: Batch-check pmds/puds just like ptes To: Ryan Roberts , Catalin Marinas , Will Deacon , Muchun Song , Pasha Tatashin , Andrew Morton , Uladzislau Rezki , Christoph Hellwig , Mark Rutland , Ard Biesheuvel , Dev Jain , Alexandre Ghiti , Steve Capper , Kevin Brodsky Cc: linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20250205151003.88959-1-ryan.roberts@arm.com> <20250205151003.88959-6-ryan.roberts@arm.com> Content-Language: en-US From: Anshuman Khandual In-Reply-To: <20250205151003.88959-6-ryan.roberts@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2/5/25 20:39, Ryan Roberts wrote: > Convert page_table_check_p[mu]d_set(...) to > page_table_check_p[mu]ds_set(..., nr) to allow checking a contiguous set > of pmds/puds in single batch. We retain page_table_check_p[mu]d_set(...) > as macros that call new batch functions with nr=1 for compatibility. > > arm64 is about to reorganise its pte/pmd/pud helpers to reuse more code > and to allow the implementation for huge_pte to more efficiently set > ptes/pmds/puds in batches. We need these batch-helpers to make the > refactoring possible. A very small nit. Although this justification here is reasonable enough but not sure if platform specific requirements, need to be spelled out in such detail for a generic MM change. > > Signed-off-by: Ryan Roberts > --- Regardless, LGTM. Reviewed-by: Anshuman Khandual > include/linux/page_table_check.h | 30 +++++++++++++++++----------- > mm/page_table_check.c | 34 +++++++++++++++++++------------- > 2 files changed, 38 insertions(+), 26 deletions(-) > > diff --git a/include/linux/page_table_check.h b/include/linux/page_table_check.h > index 6722941c7cb8..289620d4aad3 100644 > --- a/include/linux/page_table_check.h > +++ b/include/linux/page_table_check.h > @@ -19,8 +19,10 @@ void __page_table_check_pmd_clear(struct mm_struct *mm, pmd_t pmd); > void __page_table_check_pud_clear(struct mm_struct *mm, pud_t pud); > void __page_table_check_ptes_set(struct mm_struct *mm, pte_t *ptep, pte_t pte, > unsigned int nr); > -void __page_table_check_pmd_set(struct mm_struct *mm, pmd_t *pmdp, pmd_t pmd); > -void __page_table_check_pud_set(struct mm_struct *mm, pud_t *pudp, pud_t pud); > +void __page_table_check_pmds_set(struct mm_struct *mm, pmd_t *pmdp, pmd_t pmd, > + unsigned int nr); > +void __page_table_check_puds_set(struct mm_struct *mm, pud_t *pudp, pud_t pud, > + unsigned int nr); > void __page_table_check_pte_clear_range(struct mm_struct *mm, > unsigned long addr, > pmd_t pmd); > @@ -74,22 +76,22 @@ static inline void page_table_check_ptes_set(struct mm_struct *mm, > __page_table_check_ptes_set(mm, ptep, pte, nr); > } > > -static inline void page_table_check_pmd_set(struct mm_struct *mm, pmd_t *pmdp, > - pmd_t pmd) > +static inline void page_table_check_pmds_set(struct mm_struct *mm, > + pmd_t *pmdp, pmd_t pmd, unsigned int nr) > { > if (static_branch_likely(&page_table_check_disabled)) > return; > > - __page_table_check_pmd_set(mm, pmdp, pmd); > + __page_table_check_pmds_set(mm, pmdp, pmd, nr); > } > > -static inline void page_table_check_pud_set(struct mm_struct *mm, pud_t *pudp, > - pud_t pud) > +static inline void page_table_check_puds_set(struct mm_struct *mm, > + pud_t *pudp, pud_t pud, unsigned int nr) > { > if (static_branch_likely(&page_table_check_disabled)) > return; > > - __page_table_check_pud_set(mm, pudp, pud); > + __page_table_check_puds_set(mm, pudp, pud, nr); > } > > static inline void page_table_check_pte_clear_range(struct mm_struct *mm, > @@ -129,13 +131,13 @@ static inline void page_table_check_ptes_set(struct mm_struct *mm, > { > } > > -static inline void page_table_check_pmd_set(struct mm_struct *mm, pmd_t *pmdp, > - pmd_t pmd) > +static inline void page_table_check_pmds_set(struct mm_struct *mm, > + pmd_t *pmdp, pmd_t pmd, unsigned int nr) > { > } > > -static inline void page_table_check_pud_set(struct mm_struct *mm, pud_t *pudp, > - pud_t pud) > +static inline void page_table_check_puds_set(struct mm_struct *mm, > + pud_t *pudp, pud_t pud, unsigned int nr) > { > } > > @@ -146,4 +148,8 @@ static inline void page_table_check_pte_clear_range(struct mm_struct *mm, > } > > #endif /* CONFIG_PAGE_TABLE_CHECK */ > + > +#define page_table_check_pmd_set(mm, pmdp, pmd) page_table_check_pmds_set(mm, pmdp, pmd, 1) > +#define page_table_check_pud_set(mm, pudp, pud) page_table_check_puds_set(mm, pudp, pud, 1) > + > #endif /* __LINUX_PAGE_TABLE_CHECK_H */ > diff --git a/mm/page_table_check.c b/mm/page_table_check.c > index 509c6ef8de40..dae4a7d776b3 100644 > --- a/mm/page_table_check.c > +++ b/mm/page_table_check.c > @@ -234,33 +234,39 @@ static inline void page_table_check_pmd_flags(pmd_t pmd) > WARN_ON_ONCE(swap_cached_writable(pmd_to_swp_entry(pmd))); > } > > -void __page_table_check_pmd_set(struct mm_struct *mm, pmd_t *pmdp, pmd_t pmd) > +void __page_table_check_pmds_set(struct mm_struct *mm, pmd_t *pmdp, pmd_t pmd, > + unsigned int nr) > { > + unsigned int i; > + unsigned long stride = PMD_SIZE >> PAGE_SHIFT; > + > if (&init_mm == mm) > return; > > page_table_check_pmd_flags(pmd); > > - __page_table_check_pmd_clear(mm, *pmdp); > - if (pmd_user_accessible_page(pmd)) { > - page_table_check_set(pmd_pfn(pmd), PMD_SIZE >> PAGE_SHIFT, > - pmd_write(pmd)); > - } > + for (i = 0; i < nr; i++) > + __page_table_check_pmd_clear(mm, *(pmdp + i)); > + if (pmd_user_accessible_page(pmd)) > + page_table_check_set(pmd_pfn(pmd), stride * nr, pmd_write(pmd)); > } > -EXPORT_SYMBOL(__page_table_check_pmd_set); > +EXPORT_SYMBOL(__page_table_check_pmds_set); > > -void __page_table_check_pud_set(struct mm_struct *mm, pud_t *pudp, pud_t pud) > +void __page_table_check_puds_set(struct mm_struct *mm, pud_t *pudp, pud_t pud, > + unsigned int nr) > { > + unsigned int i; > + unsigned long stride = PUD_SIZE >> PAGE_SHIFT; > + > if (&init_mm == mm) > return; > > - __page_table_check_pud_clear(mm, *pudp); > - if (pud_user_accessible_page(pud)) { > - page_table_check_set(pud_pfn(pud), PUD_SIZE >> PAGE_SHIFT, > - pud_write(pud)); > - } > + for (i = 0; i < nr; i++) > + __page_table_check_pud_clear(mm, *(pudp + i)); > + if (pud_user_accessible_page(pud)) > + page_table_check_set(pud_pfn(pud), stride * nr, pud_write(pud)); > } > -EXPORT_SYMBOL(__page_table_check_pud_set); > +EXPORT_SYMBOL(__page_table_check_puds_set); > > void __page_table_check_pte_clear_range(struct mm_struct *mm, > unsigned long addr,