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 BD298C4829E for ; Thu, 15 Feb 2024 11:29:07 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 57A228D0013; Thu, 15 Feb 2024 06:29:07 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 529F98D0001; Thu, 15 Feb 2024 06:29:07 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3F2628D0013; Thu, 15 Feb 2024 06:29:07 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 2EDF08D0001 for ; Thu, 15 Feb 2024 06:29:07 -0500 (EST) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id CAD911A0FE3 for ; Thu, 15 Feb 2024 11:29:06 +0000 (UTC) X-FDA: 81793816692.26.7D0CD5A Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf24.hostedemail.com (Postfix) with ESMTP id 2AC2F180026 for ; Thu, 15 Feb 2024 11:29:04 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=none; spf=pass (imf24.hostedemail.com: domain of mark.rutland@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=mark.rutland@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=1707996545; 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: in-reply-to:in-reply-to:references:references; bh=hr3WJEqxIXVGNlaaIHvwbJlLwasf2CYRbCtidzHpGSg=; b=Gqa/45z/FzPLkklFn4vcv5mCjU2HBWoSezZczkXZE10XWKJ8Uuur06w8qx2Xo5FHLtXu9j bgJ/fq8k4+v3JJ02bFGOX6IVbN/OeiMBh9oAjYTWLVUaY8vA/+IUmFKZiHpWHGbaUdxOwB M6/57ddFz/1MCA7sdYlNoQh8CpQzxSs= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1707996545; a=rsa-sha256; cv=none; b=vir7YN/MNnlvfJlXpBU+PkPRPLJWbYx5MIjZwo8ksDYNfKM6o10sXkI1VYgPQZti4PrfkD RhabGTUy81XGyfqiKpdpmKfd3SY1dUMf/I3RiI9fTG3nrjP94pk5xjyVhaZG5YuoGymiUR E1grX0LHliF1go4tINHLLXn9gxjTNMI= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=none; spf=pass (imf24.hostedemail.com: domain of mark.rutland@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=mark.rutland@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 44F6EDA7; Thu, 15 Feb 2024 03:29:45 -0800 (PST) Received: from FVFF77S0Q05N (unknown [10.57.68.11]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id EC3FF3F7B4; Thu, 15 Feb 2024 03:29:00 -0800 (PST) Date: Thu, 15 Feb 2024 11:28:58 +0000 From: Mark Rutland To: Ryan Roberts Cc: Catalin Marinas , Will Deacon , Ard Biesheuvel , Marc Zyngier , James Morse , Andrey Ryabinin , Andrew Morton , Matthew Wilcox , David Hildenbrand , Kefeng Wang , John Hubbard , Zi Yan , Barry Song <21cnbao@gmail.com>, Alistair Popple , Yang Shi , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , linux-arm-kernel@lists.infradead.org, x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v6 14/18] arm64/mm: Implement new [get_and_]clear_full_ptes() batch APIs Message-ID: References: <20240215103205.2607016-1-ryan.roberts@arm.com> <20240215103205.2607016-15-ryan.roberts@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240215103205.2607016-15-ryan.roberts@arm.com> X-Rspamd-Queue-Id: 2AC2F180026 X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: aa4fjeojinqteo8h4pw5scgaqpb7sra6 X-HE-Tag: 1707996544-568770 X-HE-Meta: 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 XHAhvEyt DkAcCTX70lDvGaV+Aye9ih1ejXRPfpgjCQZUBjjzmDAvE3roMjyf/SNcUBCuUg4q35qFDZIlGFOyUow+PE5RGs/8Si0Q+QLQhx1QIoHLv1FqnDVkS91Wwg99Dz4BIYLW8XwOH5Gr1xm+vveh8M3SGKXw7TzUybmx1hTU7yiyjjfqtshG/OCz/ubKA8EAwja7hGbr9dSFz/Bjg/Tc1QY1tHiEjsZBXZyFaDVTLkCxGWHglKc9gTyDcUnBGxeGHWQR4irqu6HZnAW7sIa+4/2vsXKRqMvb0Ni1A6CtDhJdoQ0uKIXcvBQUdJ6+wJg== 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 Thu, Feb 15, 2024 at 10:32:01AM +0000, Ryan Roberts wrote: > Optimize the contpte implementation to fix some of the > exit/munmap/dontneed performance regression introduced by the initial > contpte commit. Subsequent patches will solve it entirely. > > During exit(), munmap() or madvise(MADV_DONTNEED), mappings must be > cleared. Previously this was done 1 PTE at a time. But the core-mm > supports batched clear via the new [get_and_]clear_full_ptes() APIs. So > let's implement those APIs and for fully covered contpte mappings, we no > longer need to unfold the contpte. This significantly reduces unfolding > operations, reducing the number of tlbis that must be issued. > > Tested-by: John Hubbard > Signed-off-by: Ryan Roberts Acked-by: Mark Rutland Mark. > --- > arch/arm64/include/asm/pgtable.h | 67 ++++++++++++++++++++++++++++++++ > arch/arm64/mm/contpte.c | 17 ++++++++ > 2 files changed, 84 insertions(+) > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index 8643227c318b..a8f1a35e3086 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -965,6 +965,37 @@ static inline pte_t __ptep_get_and_clear(struct mm_struct *mm, > return pte; > } > > +static inline void __clear_full_ptes(struct mm_struct *mm, unsigned long addr, > + pte_t *ptep, unsigned int nr, int full) > +{ > + for (;;) { > + __ptep_get_and_clear(mm, addr, ptep); > + if (--nr == 0) > + break; > + ptep++; > + addr += PAGE_SIZE; > + } > +} > + > +static inline pte_t __get_and_clear_full_ptes(struct mm_struct *mm, > + unsigned long addr, pte_t *ptep, > + unsigned int nr, int full) > +{ > + pte_t pte, tmp_pte; > + > + pte = __ptep_get_and_clear(mm, addr, ptep); > + while (--nr) { > + ptep++; > + addr += PAGE_SIZE; > + tmp_pte = __ptep_get_and_clear(mm, addr, ptep); > + if (pte_dirty(tmp_pte)) > + pte = pte_mkdirty(pte); > + if (pte_young(tmp_pte)) > + pte = pte_mkyoung(pte); > + } > + return pte; > +} > + > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR > static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm, > @@ -1160,6 +1191,11 @@ extern pte_t contpte_ptep_get(pte_t *ptep, pte_t orig_pte); > extern pte_t contpte_ptep_get_lockless(pte_t *orig_ptep); > extern void contpte_set_ptes(struct mm_struct *mm, unsigned long addr, > pte_t *ptep, pte_t pte, unsigned int nr); > +extern void contpte_clear_full_ptes(struct mm_struct *mm, unsigned long addr, > + pte_t *ptep, unsigned int nr, int full); > +extern pte_t contpte_get_and_clear_full_ptes(struct mm_struct *mm, > + unsigned long addr, pte_t *ptep, > + unsigned int nr, int full); > extern int contpte_ptep_test_and_clear_young(struct vm_area_struct *vma, > unsigned long addr, pte_t *ptep); > extern int contpte_ptep_clear_flush_young(struct vm_area_struct *vma, > @@ -1253,6 +1289,35 @@ static inline void pte_clear(struct mm_struct *mm, > __pte_clear(mm, addr, ptep); > } > > +#define clear_full_ptes clear_full_ptes > +static inline void clear_full_ptes(struct mm_struct *mm, unsigned long addr, > + pte_t *ptep, unsigned int nr, int full) > +{ > + if (likely(nr == 1)) { > + contpte_try_unfold(mm, addr, ptep, __ptep_get(ptep)); > + __clear_full_ptes(mm, addr, ptep, nr, full); > + } else { > + contpte_clear_full_ptes(mm, addr, ptep, nr, full); > + } > +} > + > +#define get_and_clear_full_ptes get_and_clear_full_ptes > +static inline pte_t get_and_clear_full_ptes(struct mm_struct *mm, > + unsigned long addr, pte_t *ptep, > + unsigned int nr, int full) > +{ > + pte_t pte; > + > + if (likely(nr == 1)) { > + contpte_try_unfold(mm, addr, ptep, __ptep_get(ptep)); > + pte = __get_and_clear_full_ptes(mm, addr, ptep, nr, full); > + } else { > + pte = contpte_get_and_clear_full_ptes(mm, addr, ptep, nr, full); > + } > + > + return pte; > +} > + > #define __HAVE_ARCH_PTEP_GET_AND_CLEAR > static inline pte_t ptep_get_and_clear(struct mm_struct *mm, > unsigned long addr, pte_t *ptep) > @@ -1337,6 +1402,8 @@ static inline int ptep_set_access_flags(struct vm_area_struct *vma, > #define set_pte __set_pte > #define set_ptes __set_ptes > #define pte_clear __pte_clear > +#define clear_full_ptes __clear_full_ptes > +#define get_and_clear_full_ptes __get_and_clear_full_ptes > #define __HAVE_ARCH_PTEP_GET_AND_CLEAR > #define ptep_get_and_clear __ptep_get_and_clear > #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG > diff --git a/arch/arm64/mm/contpte.c b/arch/arm64/mm/contpte.c > index bedb58524535..50e0173dc5ee 100644 > --- a/arch/arm64/mm/contpte.c > +++ b/arch/arm64/mm/contpte.c > @@ -212,6 +212,23 @@ void contpte_set_ptes(struct mm_struct *mm, unsigned long addr, > } > EXPORT_SYMBOL(contpte_set_ptes); > > +void contpte_clear_full_ptes(struct mm_struct *mm, unsigned long addr, > + pte_t *ptep, unsigned int nr, int full) > +{ > + contpte_try_unfold_partial(mm, addr, ptep, nr); > + __clear_full_ptes(mm, addr, ptep, nr, full); > +} > +EXPORT_SYMBOL(contpte_clear_full_ptes); > + > +pte_t contpte_get_and_clear_full_ptes(struct mm_struct *mm, > + unsigned long addr, pte_t *ptep, > + unsigned int nr, int full) > +{ > + contpte_try_unfold_partial(mm, addr, ptep, nr); > + return __get_and_clear_full_ptes(mm, addr, ptep, nr, full); > +} > +EXPORT_SYMBOL(contpte_get_and_clear_full_ptes); > + > int contpte_ptep_test_and_clear_young(struct vm_area_struct *vma, > unsigned long addr, pte_t *ptep) > { > -- > 2.25.1 >