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=-9.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 7645EC3A589 for ; Thu, 15 Aug 2019 16:49:47 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3492320578 for ; Thu, 15 Aug 2019 16:49:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="cGhgTwhh" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3492320578 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=fb.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CF4BD6B02CE; Thu, 15 Aug 2019 12:49:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C7E7C6B02D0; Thu, 15 Aug 2019 12:49:46 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B45AC6B02D1; Thu, 15 Aug 2019 12:49:46 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0123.hostedemail.com [216.40.44.123]) by kanga.kvack.org (Postfix) with ESMTP id 91F3D6B02CE for ; Thu, 15 Aug 2019 12:49:46 -0400 (EDT) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id 3C747702 for ; Thu, 15 Aug 2019 16:49:46 +0000 (UTC) X-FDA: 75825248772.13.mark05_724b2f3850f02 X-HE-Tag: mark05_724b2f3850f02 X-Filterd-Recvd-Size: 4756 Received: from mx0b-00082601.pphosted.com (mx0b-00082601.pphosted.com [67.231.153.30]) by imf12.hostedemail.com (Postfix) with ESMTP for ; Thu, 15 Aug 2019 16:49:45 +0000 (UTC) Received: from pps.filterd (m0109332.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x7FGmvNE007904 for ; Thu, 15 Aug 2019 09:49:41 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=facebook; bh=3Y6SmklECBtEUs3ZtjzJtv3IZ8WjP/QFZ+X6GbJiZHg=; b=cGhgTwhh87MxizBwskKdCGBTQLfaYZwNUxDAPii3kP+K3v//qDM+A4c21Gj7d64pnvXC SPZRVYkk9G6Ag44LJ8HOuTs7PXo4uuTtboaTeToHP61dBAGFF5QXALquqP9E4w/pKQNt gOiL+/tJd8dEJJHYluAhNYUznjnQogcqqFo= Received: from mail.thefacebook.com (mailout.thefacebook.com [199.201.64.23]) by mx0a-00082601.pphosted.com with ESMTP id 2ud7aps13f-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT) for ; Thu, 15 Aug 2019 09:49:41 -0700 Received: from mx-out.facebook.com (2620:10d:c081:10::13) by mail.thefacebook.com (2620:10d:c081:35::127) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA) id 15.1.1713.5; Thu, 15 Aug 2019 09:48:38 -0700 Received: by devbig006.ftw2.facebook.com (Postfix, from userid 4523) id DCDD862E1E4D; Thu, 15 Aug 2019 09:45:44 -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 v13 4/6] uprobe: use FOLL_SPLIT_PMD instead of FOLL_SPLIT Date: Thu, 15 Aug 2019 09:45:23 -0700 Message-ID: <20190815164525.1848545-5-songliubraving@fb.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190815164525.1848545-1-songliubraving@fb.com> References: <20190815164525.1848545-1-songliubraving@fb.com> X-FB-Internal: Safe MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-08-15_06:,, 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=892 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1908150164 X-FB-Internal: deliver 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: This patch uses newly added FOLL_SPLIT_PMD in uprobe. This preserves the huge page when the uprobe is enabled. When the uprobe is disabled, newer instances of the same application could still benefit from huge page. For the next step, we will enable khugepaged to regroup the pmd, so that existing instances of the application could also benefit from huge page after the uprobe is disabled. Acked-by: Kirill A. Shutemov Reviewed-by: Srikar Dronamraju Reviewed-by: Oleg Nesterov Signed-off-by: Song Liu --- kernel/events/uprobes.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 648f47553bff..27b596f14463 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -155,7 +155,7 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr, { struct mm_struct *mm = vma->vm_mm; struct page_vma_mapped_walk pvmw = { - .page = old_page, + .page = compound_head(old_page), .vma = vma, .address = addr, }; @@ -166,8 +166,6 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr, mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, addr, addr + PAGE_SIZE); - VM_BUG_ON_PAGE(PageTransHuge(old_page), old_page); - if (new_page) { err = mem_cgroup_try_charge(new_page, vma->vm_mm, GFP_KERNEL, &memcg, false); @@ -481,7 +479,7 @@ int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, retry: /* Read the page with vaddr into memory */ ret = get_user_pages_remote(NULL, mm, vaddr, 1, - FOLL_FORCE | FOLL_SPLIT, &old_page, &vma, NULL); + FOLL_FORCE | FOLL_SPLIT_PMD, &old_page, &vma, NULL); if (ret <= 0) return ret; -- 2.17.1