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 80A01C47258 for ; Thu, 25 Jan 2024 16:45:49 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1BDF96B00A9; Thu, 25 Jan 2024 11:45:49 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 1201B6B00AB; Thu, 25 Jan 2024 11:45:49 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F01E36B00AD; Thu, 25 Jan 2024 11:45:48 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id D92276B00AB for ; Thu, 25 Jan 2024 11:45:48 -0500 (EST) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 871F140E13 for ; Thu, 25 Jan 2024 16:45:48 +0000 (UTC) X-FDA: 81718409976.23.F6C0BE8 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf24.hostedemail.com (Postfix) with ESMTP id CC287180003 for ; Thu, 25 Jan 2024 16:45:46 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf24.hostedemail.com: domain of alexandru.elisei@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=alexandru.elisei@arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1706201147; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=xkwftJVeqouLGSxjRxX2qTSTkNnfTRKYrouvXmLFb0c=; b=yGNNjA7Id5QT0Qtubmo11UpixebtZ/hb04IQ+cFdDNXgSabXUeJZV6VgwptQDZpk8vdytw lDw/+amLVNdPAo3rDjL3eoKqTAq8gPmWGJfT4WjA6XNgLMPPm59bRhmgwdp8lODzXClPeH +E2d4QJKLlPHs3LGX1EJIhWDEyRuXTk= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf24.hostedemail.com: domain of alexandru.elisei@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=alexandru.elisei@arm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1706201147; a=rsa-sha256; cv=none; b=YP8FxEI9Yl72gBjUWpWWjhZz61dLENu2JMW9R3lw6H0utcPkkD/7qwptNbgA3o5mCyeZFJ axvRvJV5yaR7eYeBDTq0SC6USxFpseGYBDSvGi9fRJDm3HqNH8UiGCVZlE+cVFV2A5FqGT kSx/gxiQxlVu09rmZJCBYUMTFdYiftY= 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 8549C1756; Thu, 25 Jan 2024 08:46:30 -0800 (PST) Received: from e121798.cable.virginm.net (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 945353F8A4; Thu, 25 Jan 2024 08:45:40 -0800 (PST) From: Alexandru Elisei To: catalin.marinas@arm.com, will@kernel.org, oliver.upton@linux.dev, maz@kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, arnd@arndb.de, akpm@linux-foundation.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, mhiramat@kernel.org, rppt@kernel.org, hughd@google.com Cc: pcc@google.com, steven.price@arm.com, anshuman.khandual@arm.com, vincenzo.frascino@arm.com, david@redhat.com, eugenis@google.com, kcc@google.com, hyesoo.yu@samsung.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH RFC v3 31/35] khugepaged: arm64: Don't collapse MTE enabled VMAs Date: Thu, 25 Jan 2024 16:42:52 +0000 Message-Id: <20240125164256.4147-32-alexandru.elisei@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240125164256.4147-1-alexandru.elisei@arm.com> References: <20240125164256.4147-1-alexandru.elisei@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: CC287180003 X-Stat-Signature: 3jsnpr95as1jcaukrjz5am6pf1xo8rh4 X-Rspam-User: X-HE-Tag: 1706201146-534829 X-HE-Meta: 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 j9i5SFyA RB4NxuByzIrgzCokHdXkRodPNdxMhORWKJHTRiUNr/KYM01q2F5WLEiRET6tveNqCQnYq4cZrLvrwMG1VqqSz3CLuAAUNOOhh21MeWLGGaZuQYbYIBvKXtxDU0XqdzmCJS1NbuZ/tCJHz8nCEHu3IlxaDTnNj/jNTzL/Q 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: copy_user_highpage() will do memory allocation if there are saved tags for the destination page, and the page is missing tag storage. After commit a349d72fd9ef ("mm/pgtable: add rcu_read_lock() and rcu_read_unlock()s"), collapse_huge_page() calls __collapse_huge_page_copy() -> .. -> copy_user_highpage() with the RCU lock held, which means that copy_user_highpage() can only allocate memory using GFP_ATOMIC or equivalent. Get around this by refusing to collapse pages into a transparent huge page if the VMA is MTE-enabled. Signed-off-by: Alexandru Elisei --- Changes since rfc v2: * New patch. I think an agreement on whether copy*_user_highpage() should be always allowed to sleep, or should not be allowed, would be useful. arch/arm64/include/asm/pgtable.h | 3 +++ arch/arm64/kernel/mte_tag_storage.c | 5 +++++ include/linux/khugepaged.h | 5 +++++ mm/khugepaged.c | 4 ++++ 4 files changed, 17 insertions(+) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 87ae59436162..d0473538c926 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -1120,6 +1120,9 @@ static inline bool arch_alloc_cma(gfp_t gfp_mask) return true; } +bool arch_hugepage_vma_revalidate(struct vm_area_struct *vma, unsigned long address); +#define arch_hugepage_vma_revalidate arch_hugepage_vma_revalidate + #endif /* CONFIG_ARM64_MTE_TAG_STORAGE */ #endif /* CONFIG_ARM64_MTE */ diff --git a/arch/arm64/kernel/mte_tag_storage.c b/arch/arm64/kernel/mte_tag_storage.c index ac7b9c9c585c..a99959b70573 100644 --- a/arch/arm64/kernel/mte_tag_storage.c +++ b/arch/arm64/kernel/mte_tag_storage.c @@ -636,3 +636,8 @@ void arch_alloc_page(struct page *page, int order, gfp_t gfp) if (tag_storage_enabled() && alloc_requires_tag_storage(gfp)) reserve_tag_storage(page, order, gfp); } + +bool arch_hugepage_vma_revalidate(struct vm_area_struct *vma, unsigned long address) +{ + return !(vma->vm_flags & VM_MTE); +} diff --git a/include/linux/khugepaged.h b/include/linux/khugepaged.h index f68865e19b0b..461e4322dff2 100644 --- a/include/linux/khugepaged.h +++ b/include/linux/khugepaged.h @@ -38,6 +38,11 @@ static inline void khugepaged_exit(struct mm_struct *mm) if (test_bit(MMF_VM_HUGEPAGE, &mm->flags)) __khugepaged_exit(mm); } + +#ifndef arch_hugepage_vma_revalidate +#define arch_hugepage_vma_revalidate(vma, address) 1 +#endif + #else /* CONFIG_TRANSPARENT_HUGEPAGE */ static inline void khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm) { diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 2b219acb528e..cb9a9ddb4d86 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -935,6 +935,10 @@ static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address, */ if (expect_anon && (!(*vmap)->anon_vma || !vma_is_anonymous(*vmap))) return SCAN_PAGE_ANON; + + if (!arch_hugepage_vma_revalidate(vma, address)) + return SCAN_VMA_CHECK; + return SCAN_SUCCEED; } -- 2.43.0