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 X-Spam-Level: X-Spam-Status: No, score=-7.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C71CCC31E45 for ; Thu, 13 Jun 2019 17:13:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A024E2063F for ; Thu, 13 Jun 2019 17:13:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="d5Nfvqxa" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404697AbfFMRNG (ORCPT ); Thu, 13 Jun 2019 13:13:06 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:50694 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728989AbfFLWGW (ORCPT ); Wed, 12 Jun 2019 18:06:22 -0400 Received: from pps.filterd (m0001303.ppops.net [127.0.0.1]) by m0001303.ppops.net (8.16.0.27/8.16.0.27) with SMTP id x5CM38rn013351 for ; Wed, 12 Jun 2019 15:06:20 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : mime-version : content-type; s=facebook; bh=mJVdksI83pcAr/2dwtDaBJBK6Rf/MpbqiwJ18bpKuB4=; b=d5NfvqxaVKUz9etwwx4Nb7+wyFk01khAYRPNJLsjj2+STh6cFzBwfLiq29ym6MB+KcFW Mb7+x8G8WPMbUgRhGd1tNxEEDPcZC6e6UZ8RmBnva888nfZe+vsx5zFRF2Ka93ILxqsL qm5as3D/b87YltgWMuCZEUdCA4BzLdNRgTU= Received: from maileast.thefacebook.com ([163.114.130.16]) by m0001303.ppops.net with ESMTP id 2t356213fd-8 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 12 Jun 2019 15:06:20 -0700 Received: from mx-out.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Wed, 12 Jun 2019 15:06:16 -0700 Received: by devbig006.ftw2.facebook.com (Postfix, from userid 4523) id 8320F62E2085; Wed, 12 Jun 2019 15:03:23 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Song Liu Smtp-Origin-Hostname: devbig006.ftw2.facebook.com To: , CC: , , , , , , , , Song Liu Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH v3 0/5] THP aware uprobe Date: Wed, 12 Jun 2019 15:03:14 -0700 Message-ID: <20190612220320.2223898-1-songliubraving@fb.com> X-Mailer: git-send-email 2.17.1 X-FB-Internal: Safe MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-06-12_13:,, signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906120153 X-FB-Internal: deliver Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This set makes uprobe aware of THPs. Currently, when uprobe is attached to text on THP, the page is split by FOLL_SPLIT. As a result, uprobe eliminates the performance benefit of THP. This set makes uprobe THP-aware. Instead of FOLL_SPLIT, we introduces FOLL_SPLIT_PMD, which only split PMD for uprobe. After all uprobes within the THP are removed, the PTEs are regrouped into huge PMD. Note that, with uprobes attached, the process runs with PTEs for the huge page. The performance benefit of THP is recovered _after_ all uprobes on the huge page are detached. This set (plus a few THP patches) is also available at https://github.com/liu-song-6/linux/tree/uprobe-thp Changes since v2: 1. For FOLL_SPLIT_PMD, populated the page table in follow_pmd_mask(). 2. Simplify logic in uprobe_write_opcode. (Oleg Nesterov) 3. Fix page refcount handling with FOLL_SPLIT_PMD. 4. Much more testing, together with THP on ext4 and btrfs (sending in separate set). 5. Rebased up on Linus's tree: commit 35110e38e6c5 ("Merge tag 'media/v5.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media") Changes since v1: 1. introduces FOLL_SPLIT_PMD, instead of modifying split_huge_pmd*(); 2. reuse pages_identical() from ksm.c; 3. rewrite most of try_collapse_huge_pmd(). Song Liu (5): mm: move memcmp_pages() and pages_identical() uprobe: use original page when all uprobes are removed mm, thp: introduce FOLL_SPLIT_PMD uprobe: use FOLL_SPLIT_PMD instead of FOLL_SPLIT uprobe: collapse THP pmd after removing all uprobes include/linux/huge_mm.h | 7 +++++ include/linux/mm.h | 8 ++++++ kernel/events/uprobes.c | 54 ++++++++++++++++++++++++++-------- mm/gup.c | 38 ++++++++++++++++++++++-- mm/huge_memory.c | 64 +++++++++++++++++++++++++++++++++++++++++ mm/ksm.c | 18 ------------ mm/util.c | 13 +++++++++ 7 files changed, 169 insertions(+), 33 deletions(-) -- 2.17.1