From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga07-in.huawei.com (szxga07-in.huawei.com [45.249.212.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A79643B182 for ; Tue, 2 Apr 2024 07:53:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.35 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712044401; cv=none; b=MBBq1CSOvebUlHv3jaeKDmAe9Wh6AFdQDcCAQGZJ59IDlinnP5H1LLBjIxXSsTRm4dPhjdYrQ9dSFeUrFsRXzvSA1Fh7NaozPAYXq1jHEurBcRilkVH7wZuYh7QZfRxYyOosfAatdDaHEp/N0CbGUjU2seQrKwdPOrYOxX7afOw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712044401; c=relaxed/simple; bh=f5Lfx8Z1LVutbiVem9ddvHtwjxzHzxAlFhUCIKFEenI=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=H0U5nQ9J9Q5XyXwqjUxfKPX7ehFVgPVLY55fT4P5GUvwl2DQSdPQ3YiiYQ3D3IoPl68tGKmV1Ev0slkx4mxpXBbL+sQEizFv8Mf7cyKDTfnVHD3S/1Go+4qJhae9ejzuENd/lO5uceF1iW4b//0VTFMif6JZMo+uB3CEvemJ36M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.35 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com 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> Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm100001.china.huawei.com (7.185.36.93) 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 --- 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))) -- 2.27.0