From patchwork Fri Sep 27 23:40:00 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leonardo Bras X-Patchwork-Id: 1168767 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=kvm-ppc-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.ibm.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 46g7bs5jhCz9sRW for ; Sat, 28 Sep 2019 09:41:29 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728548AbfI0XlQ (ORCPT ); Fri, 27 Sep 2019 19:41:16 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:12834 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728487AbfI0XlQ (ORCPT ); Fri, 27 Sep 2019 19:41:16 -0400 Received: from pps.filterd (m0187473.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x8RNbRhk073243; Fri, 27 Sep 2019 19:40:38 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 2v8y3bhkbu-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 27 Sep 2019 19:40:38 -0400 Received: from m0187473.ppops.net (m0187473.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.27/8.16.0.27) with SMTP id x8RNbx3N073774; Fri, 27 Sep 2019 19:40:38 -0400 Received: from ppma04dal.us.ibm.com (7a.29.35a9.ip4.static.sl-reverse.com [169.53.41.122]) by mx0a-001b2d01.pphosted.com with ESMTP id 2v8y3bhkbj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 27 Sep 2019 19:40:37 -0400 Received: from pps.filterd (ppma04dal.us.ibm.com [127.0.0.1]) by ppma04dal.us.ibm.com (8.16.0.27/8.16.0.27) with SMTP id x8RNePTg007480; Fri, 27 Sep 2019 23:40:37 GMT Received: from b01cxnp23034.gho.pok.ibm.com (b01cxnp23034.gho.pok.ibm.com [9.57.198.29]) by ppma04dal.us.ibm.com with ESMTP id 2v5bg8k6jr-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 27 Sep 2019 23:40:36 +0000 Received: from b01ledav004.gho.pok.ibm.com (b01ledav004.gho.pok.ibm.com [9.57.199.109]) by b01cxnp23034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x8RNeamu51970498 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 27 Sep 2019 23:40:36 GMT Received: from b01ledav004.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 03575112062; Fri, 27 Sep 2019 23:40:36 +0000 (GMT) Received: from b01ledav004.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5291A112063; Fri, 27 Sep 2019 23:40:32 +0000 (GMT) Received: from LeoBras.aus.stglabs.ibm.com (unknown [9.18.235.58]) by b01ledav004.gho.pok.ibm.com (Postfix) with ESMTP; Fri, 27 Sep 2019 23:40:32 +0000 (GMT) From: Leonardo Bras To: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, kvm-ppc@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org Cc: Leonardo Bras , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Arnd Bergmann , "Aneesh Kumar K.V" , Christophe Leroy , Andrew Morton , Dan Williams , Nicholas Piggin , Mahesh Salgaonkar , Allison Randal , Thomas Gleixner , Ganesh Goudar , Mike Rapoport , YueHaibing , Greg Kroah-Hartman , Ira Weiny , Jason Gunthorpe , John Hubbard , Keith Busch Subject: [PATCH v4 03/11] mm/gup: Applies counting method to monitor gup_pgd_range Date: Fri, 27 Sep 2019 20:40:00 -0300 Message-Id: <20190927234008.11513-4-leonardo@linux.ibm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190927234008.11513-1-leonardo@linux.ibm.com> References: <20190927234008.11513-1-leonardo@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-09-27_09:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=731 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1909270205 Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org As decribed, gup_pgd_range is a lockless pagetable walk. So, in order to monitor against THP split/collapse with the couting method, it's necessary to bound it with {start,end}_lockless_pgtbl_walk. There are dummy functions, so it is not going to add any overhead on archs that don't use this method. Signed-off-by: Leonardo Bras --- mm/gup.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/mm/gup.c b/mm/gup.c index 98f13ab37bac..7105c829cf44 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -2325,6 +2325,7 @@ static bool gup_fast_permitted(unsigned long start, unsigned long end) int __get_user_pages_fast(unsigned long start, int nr_pages, int write, struct page **pages) { + struct mm_struct *mm; unsigned long len, end; unsigned long flags; int nr = 0; @@ -2352,9 +2353,12 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, if (IS_ENABLED(CONFIG_HAVE_FAST_GUP) && gup_fast_permitted(start, end)) { + mm = current->mm; + start_lockless_pgtbl_walk(mm); local_irq_save(flags); gup_pgd_range(start, end, write ? FOLL_WRITE : 0, pages, &nr); local_irq_restore(flags); + end_lockless_pgtbl_walk(mm); } return nr; @@ -2404,6 +2408,7 @@ int get_user_pages_fast(unsigned long start, int nr_pages, unsigned int gup_flags, struct page **pages) { unsigned long addr, len, end; + struct mm_struct *mm; int nr = 0, ret = 0; if (WARN_ON_ONCE(gup_flags & ~(FOLL_WRITE | FOLL_LONGTERM))) @@ -2421,9 +2426,12 @@ int get_user_pages_fast(unsigned long start, int nr_pages, if (IS_ENABLED(CONFIG_HAVE_FAST_GUP) && gup_fast_permitted(start, end)) { + mm = current->mm; + start_lockless_pgtbl_walk(mm); local_irq_disable(); gup_pgd_range(addr, end, gup_flags, pages, &nr); local_irq_enable(); + end_lockless_pgtbl_walk(mm); ret = nr; }