From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4121BC02194 for ; Thu, 6 Feb 2025 13:08:06 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 840B16B0082; Thu, 6 Feb 2025 08:08:05 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 7F1156B0083; Thu, 6 Feb 2025 08:08:05 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6B8826B0085; Thu, 6 Feb 2025 08:08:05 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 4EFC76B0082 for ; Thu, 6 Feb 2025 08:08:05 -0500 (EST) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 10BF3B1982 for ; Thu, 6 Feb 2025 13:08:05 +0000 (UTC) X-FDA: 83089547730.02.3774830 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf18.hostedemail.com (Postfix) with ESMTP id 467031C0077 for ; Thu, 6 Feb 2025 13:08:03 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=none; spf=pass (imf18.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1738847283; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=67BEcOVTAEE0TOmQPQF4Hx8qLpCcB/5I8uUeqsPN1no=; b=2ei5H5A4JZIhtQeDO4MgTmC7vaMpSCST7zsSCLfScpi/Aj6ltMdiAzEh+g8DIu2wMfgIYj aFxKEDtPsyCnc/NV5oXdvxNJwaoqJ1Lh1SLM0DdqIXZwbl46TQdSn6djoQcNzbF6M/SfvE TyEGdRABspacqO40Qi3mmjBlKUq68ZQ= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1738847283; a=rsa-sha256; cv=none; b=Tr2gmPhmKSchhlnz+P0jDKSUd988R4tGJZqChOOQCmkMJmgAE0aO0ydt2ihE7OPb+pnqzv 3PA6F3+UfDrSD/Us5WIlOJIP3y1naY4UUZKAcD/pgsy6xSoSijOFDlfLlWNSzOj3o4U7nb 6/vBhDMVTXLccVYM4OhhahsySHrFekM= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=none; spf=pass (imf18.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com; dmarc=pass (policy=none) header.from=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 C82F8FEC; Thu, 6 Feb 2025 05:08:25 -0800 (PST) Received: from [10.57.80.166] (unknown [10.57.80.166]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AB8383F5A1; Thu, 6 Feb 2025 05:07:59 -0800 (PST) Message-ID: Date: Thu, 6 Feb 2025 13:07:32 +0000 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 Content-Language: en-GB To: Anshuman Khandual , 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> From: Ryan Roberts In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Stat-Signature: 1y4g8iap9brue5obio8n9ef316yn46tr X-Rspamd-Queue-Id: 467031C0077 X-Rspam-User: X-Rspamd-Server: rspam06 X-HE-Tag: 1738847283-657804 X-HE-Meta: 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 1qwJom2t Qnr4BbKZ1jV6hOCjboNdJ2qEH1Awjw0rmhZ1G6yXWGer9rKr+0wpC6hhyVb/6YwWnaFCDNhzTwoJnUdmdvz/7hXYOYvxugIOWnofvLGowygHwBcjJ3OE0XvQYAJjNdy1YLOciAwdH3oWcfeaqyTpwqyZZK/l97zFTaYheU1WYOyg8jKJHAWpD5IqCc7Xnkum0NRVRBqvDZiID7ZG/0tMat5IDNAfvsxcekjUmiMb+YKB+U5b98nS/9db5Wg== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 06/02/2025 10:55, Anshuman Khandual wrote: > 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. Personally I find the "why" to be the most useful part of a commit log. I'd prefer to leave it in unless any mm people complain. > >> >> Signed-off-by: Ryan Roberts >> --- > > Regardless, LGTM. > > Reviewed-by: Anshuman Khandual Thanks! > >> 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,