From patchwork Tue Apr 2 07:51:37 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kefeng Wang X-Patchwork-Id: 13613526 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 36002CD1297 for ; Tue, 2 Apr 2024 07:53:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Br+B5FD+eBE8FjgmDUhjx3mbWMpabhFmnIro+5w0w2A=; b=B6Hw45y7CNuuEn DfseTCyFPo6LhD/7lm9YIYWb9/+eyr9SLIZlwAzKQM3/EaPbpYNY8UHyWUqFyTlXFbM8j9lClvyH+ oNm0u9UfLn88fJ6iJaWPwut9Kr3Pm7klO/5b4Ppq6odYtw1Sl79tJk8852aOM7elaHGC4/uf35Fn3 HeFbJ5ATs+QZfgxdzx6uJew8y2sklLVBEYKbLSXx8gZlPGQKAOuJMRfsyhvi1f9s6tf3b+tJcWSCw 8PEywk7tqJ//A8oMbMCql1+UN75VwhYsIy4oSk2/0v6TkTkElzmvQgdixuRWgThw6qlfu1AbyrTDb ALkrqyLfyL1nzN0+r9Yw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rrYxU-0000000A87U-1Xlm; Tue, 02 Apr 2024 07:53:28 +0000 Received: from szxga07-in.huawei.com ([45.249.212.35]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rrYxN-0000000A81i-3Hue; Tue, 02 Apr 2024 07:53:23 +0000 Received: from mail.maildlp.com (unknown [172.19.88.163]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4V80RX18nRz1R9YK; Tue, 2 Apr 2024 15:50:32 +0800 (CST) Received: from dggpemm100001.china.huawei.com (unknown [7.185.36.93]) by mail.maildlp.com (Postfix) with ESMTPS id 3C3F0180060; Tue, 2 Apr 2024 15:53:17 +0800 (CST) Received: from localhost.localdomain (10.175.112.125) by dggpemm100001.china.huawei.com (7.185.36.93) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Tue, 2 Apr 2024 15:53:16 +0800 From: Kefeng Wang To: CC: Russell King , Catalin Marinas , Will Deacon , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexander Gordeev , Gerald Schaefer , Dave Hansen , Andy Lutomirski , Peter Zijlstra , , , , , , , Kefeng Wang Subject: [PATCH 2/7] arm64: mm: accelerate pagefault when VM_FAULT_BADACCESS Date: Tue, 2 Apr 2024 15:51:37 +0800 Message-ID: <20240402075142.196265-3-wangkefeng.wang@huawei.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20240402075142.196265-1-wangkefeng.wang@huawei.com> References: <20240402075142.196265-1-wangkefeng.wang@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.112.125] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm100001.china.huawei.com (7.185.36.93) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240402_005322_040369_2DDE666B X-CRM114-Status: GOOD ( 11.05 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org The vm_flags of vma already checked under per-VMA lock, if it is a bad access, directly set fault to VM_FAULT_BADACCESS and handle error, no need to lock_mm_and_find_vma() and check vm_flags again, the latency time reduce 34% in lmbench 'lat_sig -P 1 prot lat_sig'. Signed-off-by: Kefeng Wang Reviewed-by: Suren Baghdasaryan Reviewed-by: Catalin Marinas --- arch/arm64/mm/fault.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 9bb9f395351a..405f9aa831bd 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -572,7 +572,9 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr, if (!(vma->vm_flags & vm_flags)) { vma_end_read(vma); - goto lock_mmap; + fault = VM_FAULT_BADACCESS; + count_vm_vma_lock_event(VMA_LOCK_SUCCESS); + goto done; } fault = handle_mm_fault(vma, addr, mm_flags | FAULT_FLAG_VMA_LOCK, regs); if (!(fault & (VM_FAULT_RETRY | VM_FAULT_COMPLETED)))