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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 D56B9CD128A for ; Sun, 7 Apr 2024 07:50:59 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4VC4Ck2x0Vz3vc0 for ; Sun, 7 Apr 2024 17:50:58 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=huawei.com (client-ip=45.249.212.187; helo=szxga01-in.huawei.com; envelope-from=wangkefeng.wang@huawei.com; receiver=lists.ozlabs.org) Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4VC4CG6Fwdz3btX for ; Sun, 7 Apr 2024 17:50:32 +1000 (AEST) Received: from mail.maildlp.com (unknown [172.19.88.105]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4VC47C1yhVzwRPw; Sun, 7 Apr 2024 15:47:03 +0800 (CST) Received: from dggpemm100001.china.huawei.com (unknown [7.185.36.93]) by mail.maildlp.com (Postfix) with ESMTPS id 5A70414010C; Sun, 7 Apr 2024 15:49:55 +0800 (CST) Received: from [10.174.177.243] (10.174.177.243) 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; Sun, 7 Apr 2024 15:49:54 +0800 Message-ID: <4d45fffc-877a-4ad1-ad02-a33341e467e7@huawei.com> Date: Sun, 7 Apr 2024 15:49:53 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 0/7] arch/mm/fault: accelerate pagefault when badaccess Content-Language: en-US To: Andrew Morton References: <20240403083805.1818160-1-wangkefeng.wang@huawei.com> <20240403134539.fde3a6c594f2d88409be30ed@linux-foundation.org> From: Kefeng Wang In-Reply-To: <20240403134539.fde3a6c594f2d88409be30ed@linux-foundation.org> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.243] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm100001.china.huawei.com (7.185.36.93) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: x86@kernel.org, linux-s390@vger.kernel.org, Albert Ou , linuxppc-dev@lists.ozlabs.org, Peter Zijlstra , Catalin Marinas , Paul Walmsley , Russell King , surenb@google.com, Dave Hansen , linux-riscv@lists.infradead.org, Palmer Dabbelt , Nicholas Piggin , Andy Lutomirski , Alexander Gordeev , Will Deacon , Gerald Schaefer , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 2024/4/4 4:45, Andrew Morton wrote: > On Wed, 3 Apr 2024 16:37:58 +0800 Kefeng Wang wrote: > >> After VMA lock-based page fault handling enabled, if bad access met >> under per-vma lock, it will fallback to mmap_lock-based handling, >> so it leads to unnessary mmap lock and vma find again. A test from >> lmbench shows 34% improve after this changes on arm64, >> >> lat_sig -P 1 prot lat_sig 0.29194 -> 0.19198 >> >> Only build test on other archs except arm64. > > Thanks. So we now want a bunch of architectures to runtime test this. Do > we have a selftest in place which will adequately do this? I don't find such selftest, and badaccess would lead to coredump, the performance should not affect most scene, so no selftest is acceptable. lmbench is easy to use to measure the performance.