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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 8E1DAC10F14 for ; Thu, 3 Oct 2019 01:36:27 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4B365222BE for ; Thu, 3 Oct 2019 01:36:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4B365222BE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id EE7AC6B0272; Wed, 2 Oct 2019 21:36:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EC00B6B0273; Wed, 2 Oct 2019 21:36:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DAF666B0274; Wed, 2 Oct 2019 21:36:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0186.hostedemail.com [216.40.44.186]) by kanga.kvack.org (Postfix) with ESMTP id B9CDF6B0272 for ; Wed, 2 Oct 2019 21:36:26 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 7309E181AC9AE for ; Thu, 3 Oct 2019 01:36:26 +0000 (UTC) X-FDA: 76000758372.29.chin63_55423e19dd933 X-HE-Tag: chin63_55423e19dd933 X-Filterd-Recvd-Size: 6434 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by imf18.hostedemail.com (Postfix) with ESMTP for ; Thu, 3 Oct 2019 01:36:25 +0000 (UTC) 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 x931WUMV055290; Wed, 2 Oct 2019 21:36:07 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 2vd1gy0hnj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 02 Oct 2019 21:36:06 -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 x931Wbwg055561; Wed, 2 Oct 2019 21:36:05 -0400 Received: from ppma04wdc.us.ibm.com (1a.90.2fa9.ip4.static.sl-reverse.com [169.47.144.26]) by mx0a-001b2d01.pphosted.com with ESMTP id 2vd1gy0hn5-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 02 Oct 2019 21:36:05 -0400 Received: from pps.filterd (ppma04wdc.us.ibm.com [127.0.0.1]) by ppma04wdc.us.ibm.com (8.16.0.27/8.16.0.27) with SMTP id x931U5BT025461; Thu, 3 Oct 2019 01:36:04 GMT Received: from b03cxnp08028.gho.boulder.ibm.com (b03cxnp08028.gho.boulder.ibm.com [9.17.130.20]) by ppma04wdc.us.ibm.com with ESMTP id 2v9y588ega-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 03 Oct 2019 01:36:04 +0000 Received: from b03ledav004.gho.boulder.ibm.com (b03ledav004.gho.boulder.ibm.com [9.17.130.235]) by b03cxnp08028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x931a2MW66126324 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 3 Oct 2019 01:36:02 GMT Received: from b03ledav004.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3CAB578060; Thu, 3 Oct 2019 01:36:02 +0000 (GMT) Received: from b03ledav004.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C03DC7805E; Thu, 3 Oct 2019 01:35:49 +0000 (GMT) Received: from LeoBras.ibmuc.com (unknown [9.85.174.224]) by b03ledav004.gho.boulder.ibm.com (Postfix) with ESMTP; Thu, 3 Oct 2019 01:35:49 +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 , Nicholas Piggin , Andrew Morton , Mahesh Salgaonkar , Reza Arbab , Santosh Sivaraj , Balbir Singh , Thomas Gleixner , Greg Kroah-Hartman , Mike Rapoport , Allison Randal , Jason Gunthorpe , Dan Williams , Vlastimil Babka , Christoph Lameter , Logan Gunthorpe , Andrey Ryabinin , Alexey Dobriyan , Souptick Joarder , Mathieu Desnoyers , Ralph Campbell , Jesper Dangaard Brouer , Jann Horn , Davidlohr Bueso , "Peter Zijlstra (Intel)" , Ingo Molnar , Christian Brauner , Michal Hocko , Elena Reshetova , Roman Gushchin , Andrea Arcangeli , Al Viro , "Dmitry V. Levin" , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Song Liu , Bartlomiej Zolnierkiewicz , Ira Weiny , "Kirill A. Shutemov" , John Hubbard , Keith Busch Subject: [PATCH v5 10/11] mm/Kconfig: Adds config option to track lockless pagetable walks Date: Wed, 2 Oct 2019 22:33:24 -0300 Message-Id: <20191003013325.2614-11-leonardo@linux.ibm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191003013325.2614-1-leonardo@linux.ibm.com> References: <20191003013325.2614-1-leonardo@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-10-03_01:,, 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=974 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1910030012 Content-Transfer-Encoding: quoted-printable 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: Adds config option LOCKLESS_PAGE_TABLE_WALK_TRACKING to make possible enabling tracking lockless pagetable walks directly from kernel config. Signed-off-by: Leonardo Bras --- mm/Kconfig | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/mm/Kconfig b/mm/Kconfig index a5dae9a7eb51..00f487a0122f 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -736,4 +736,15 @@ config ARCH_HAS_PTE_SPECIAL config ARCH_HAS_HUGEPD bool =20 +config LOCKLESS_PAGE_TABLE_WALK_TRACKING + bool "Track (and optimize) lockless page table walks" + default n + + help + Maintain a reference count of active lockless page table + walkers. This adds 4 bytes to struct mm size, and two atomic + operations to calls such as get_user_pages_fast(). Some + architectures can optimize lockless page table operations if + this is enabled. + endmenu --=20 2.20.1