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=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 47919C04E53 for ; Wed, 15 May 2019 17:17:59 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DF3A82084E for ; Wed, 15 May 2019 17:17:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="rEObaRHC"; dkim=pass (1024-bit key) header.d=fb.onmicrosoft.com header.i=@fb.onmicrosoft.com header.b="JJ6czcJ5" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DF3A82084E 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 690A46B0005; Wed, 15 May 2019 13:17:58 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 667AF6B0006; Wed, 15 May 2019 13:17:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 508456B0007; Wed, 15 May 2019 13:17:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-vs1-f72.google.com (mail-vs1-f72.google.com [209.85.217.72]) by kanga.kvack.org (Postfix) with ESMTP id 2C35F6B0005 for ; Wed, 15 May 2019 13:17:58 -0400 (EDT) Received: by mail-vs1-f72.google.com with SMTP id 2so103507vsp.23 for ; Wed, 15 May 2019 10:17:58 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:dkim-signature:from:to:cc:subject :thread-topic:thread-index:date:message-id:references:in-reply-to :accept-language:content-language:content-id :content-transfer-encoding:mime-version; bh=HE2MZiOXjgj8hgaGwMJPCyOpBUfLUlcBZGgaIA1NrUM=; b=oAy7eH5SU7DAJrSrXwVRZ2WB/H1U3tDVy8zBfkdK1eg8+g9lEltdFPaJoM3sKpkYGI EzsVJx9g1ghjxd7N5TCE2NT64jkVWhUr0+QlmgDjLYZsRjX4kk/x/0rCmpgr2BEKQOOw skWJ7WGvpsvvxzqN39yGTWVDaT7aQetgd9Bdi2/SaU/3kLrgldYdEZsmHIztQMDfep4C dAFtfpE4tUyAkwyYgYTsxujgYVwMW9+bqr6htgHG7M0xf41ZtVBgiCAl7unRoM9vNi4B 3tUKsAbOofhuOm1TPbgGwuL3kdK35YTjdJ3mjxSU2GlMrUEh6TLl6Z3OlG7TK0LQd/pI W3fw== X-Gm-Message-State: APjAAAVBLwoILusOxZRbOz58RaIhPaIPv7PiDfaqQJDOYkXmP9I0bzj7 CuBjHsYFWSq169fJ+zmZFVmBvMrE3dmbaPzadQBFRZxZx9lWIPxKcQqDiHFAor4h6WESaleMVvq 4elgTSZ2xawQ0C3n+4w/T4t7c9XGZ8SKLR+Fii3mIdVCNqhcr3sy4KUko71vcBsgnTw== X-Received: by 2002:a67:fd93:: with SMTP id k19mr7153314vsq.45.1557940677759; Wed, 15 May 2019 10:17:57 -0700 (PDT) X-Google-Smtp-Source: APXvYqxB+EVx1hIH12cm+2nKLIzJTfYJZqyC1AY4HKa/bih77BVlrFxOmh5xtSWGESiKxB/v8Pel X-Received: by 2002:a67:fd93:: with SMTP id k19mr7153270vsq.45.1557940676879; Wed, 15 May 2019 10:17:56 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1557940676; cv=none; d=google.com; s=arc-20160816; b=x6GECp8C/WtkHKahkHxvXikrvrFkfLoXN716rP9seOUg2Jxg9VvpQMSnA20lpm3RGc apuO31fKtFNX1Fb1/KJWVmwtUaUnGqIx7hB0FX4+y+OlAbI/sO2Qw8EyjFNrNhe0Z6jN w62rbKvajt1/pqMgebW3Po48tDzslmgL8V4I/FGRtC6Wz1QLdV92ewBrrrgxSKgrekgo XDP5hTY0okj821pc9dQfbQgEAzXqXkCd9QgF3SE4vxFEbq2hL50apzkMh8qHu84hrSmb whhk2d31svZyMOd2h2Y/ly4F0mSVBnIIzgtt8ivrAYuPqPcMUt/IQMKogPGlH61T4Miu FtpQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:content-transfer-encoding:content-id:content-language :accept-language:in-reply-to:references:message-id:date:thread-index :thread-topic:subject:cc:to:from:dkim-signature:dkim-signature; bh=HE2MZiOXjgj8hgaGwMJPCyOpBUfLUlcBZGgaIA1NrUM=; b=pifXH8+yQNDQHOARmuglfPtV2UdnnSg0NObbr770GLwqTgRo1tZ5V80ece4OSJz8Ce etEZNmd0p2URgeq6ezyPNWjTXmgkq0nVMXzxanbF6DraCuu/hkW+FkEwHkMeUSoeItXq Ak/EEwIqCXBkniPICi+NMQSeFI8XMtOBTGtLKICDuo6T0yWY3RimPJ3FrcLjPNJ94phz Hq4PIZXdVAVpqgF3McTAM9jOYfQdLGGdr571rbifMUmG1cBlPkWhx8rluePRRW0BfcmE bd4qdMjcpX9oLR30Bu/DfhQimPPgREFoQNorH145q8RKAxtVZzxc8PsFjVvs0dYHJ8l7 GTWg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@fb.com header.s=facebook header.b=rEObaRHC; dkim=pass header.i=@fb.onmicrosoft.com header.s=selector1-fb-onmicrosoft-com header.b=JJ6czcJ5; spf=pass (google.com: domain of prvs=0038d347e3=guro@fb.com designates 67.231.153.30 as permitted sender) smtp.mailfrom="prvs=0038d347e3=guro@fb.com"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=fb.com Received: from mx0a-00082601.pphosted.com (mx0b-00082601.pphosted.com. [67.231.153.30]) by mx.google.com with ESMTPS id n10si672841vsp.99.2019.05.15.10.17.56 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 15 May 2019 10:17:56 -0700 (PDT) Received-SPF: pass (google.com: domain of prvs=0038d347e3=guro@fb.com designates 67.231.153.30 as permitted sender) client-ip=67.231.153.30; Authentication-Results: mx.google.com; dkim=pass header.i=@fb.com header.s=facebook header.b=rEObaRHC; dkim=pass header.i=@fb.onmicrosoft.com header.s=selector1-fb-onmicrosoft-com header.b=JJ6czcJ5; spf=pass (google.com: domain of prvs=0038d347e3=guro@fb.com designates 67.231.153.30 as permitted sender) smtp.mailfrom="prvs=0038d347e3=guro@fb.com"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=fb.com Received: from pps.filterd (m0001255.ppops.net [127.0.0.1]) by mx0b-00082601.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x4FHGMFS015521; Wed, 15 May 2019 10:17:38 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : references : in-reply-to : content-type : content-id : content-transfer-encoding : mime-version; s=facebook; bh=HE2MZiOXjgj8hgaGwMJPCyOpBUfLUlcBZGgaIA1NrUM=; b=rEObaRHC50A8l562hy8A9bbD6Q2j+jE6K6UV2qmBl58a9fq4PouoThsPIjdVTzgksJB7 hTPSSl7zluiVCYscvQSvSloDGa3xXL8Jxw76sc+yherRGIVlCL1mIJDPJjiAhXmweQ/B MkXjv7Fa74LjR3bgYmoTWhGzVp6a7fbY11k= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0b-00082601.pphosted.com with ESMTP id 2sg4chkh6r-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT); Wed, 15 May 2019 10:17:38 -0700 Received: from ash-exopmbx201.TheFacebook.com (2620:10d:c0a8:83::8) by ash-exhub202.TheFacebook.com (2620:10d:c0a8:83::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Wed, 15 May 2019 10:17:36 -0700 Received: from ash-exhub103.TheFacebook.com (2620:10d:c0a8:82::c) by ash-exopmbx201.TheFacebook.com (2620:10d:c0a8:83::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Wed, 15 May 2019 10:17:35 -0700 Received: from NAM04-SN1-obe.outbound.protection.outlook.com (100.104.31.183) by o365-in.thefacebook.com (100.104.35.174) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.1713.5 via Frontend Transport; Wed, 15 May 2019 10:17:35 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.onmicrosoft.com; s=selector1-fb-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=HE2MZiOXjgj8hgaGwMJPCyOpBUfLUlcBZGgaIA1NrUM=; b=JJ6czcJ5UltQ8BqcTMO1sOEY2mr4zzKfn6CzQSEDbcJYV5IUqgMdXUzAvXdmF6gRmmOfAudK3Q6uA63PWh49fDvihKkxTUI2xBHEP2zD7e53EFIqAfOWlKRS92iKM/T+iluBiHp1EXunGKfQNZ17VfoY5GrF5dbWr1xYm+Nf7rk= Received: from BYAPR15MB2631.namprd15.prod.outlook.com (20.179.156.24) by BYAPR15MB3272.namprd15.prod.outlook.com (20.179.57.152) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.1900.16; Wed, 15 May 2019 17:17:34 +0000 Received: from BYAPR15MB2631.namprd15.prod.outlook.com ([fe80::d4f6:b485:69ee:fd9a]) by BYAPR15MB2631.namprd15.prod.outlook.com ([fe80::d4f6:b485:69ee:fd9a%7]) with mapi id 15.20.1878.024; Wed, 15 May 2019 17:17:34 +0000 From: Roman Gushchin To: Anshuman Khandual CC: Andrew Morton , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , Kernel Team , "Johannes Weiner" , Matthew Wilcox , Vlastimil Babka Subject: Re: [PATCH] mm: refactor __vunmap() to avoid duplicated call to find_vm_area() Thread-Topic: [PATCH] mm: refactor __vunmap() to avoid duplicated call to find_vm_area() Thread-Index: AQHVCq//khAEDBlALkSFD6zmmU+RfaZrzesAgACg2oA= Date: Wed, 15 May 2019 17:17:33 +0000 Message-ID: <20190515171729.GC9307@castle> References: <20190514235111.2817276-1-guro@fb.com> <7ad2b16d-c1a3-b826-df4d-6d9ed1d9fc9f@arm.com> In-Reply-To: <7ad2b16d-c1a3-b826-df4d-6d9ed1d9fc9f@arm.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-clientproxiedby: CO1PR15CA0048.namprd15.prod.outlook.com (2603:10b6:101:1f::16) To BYAPR15MB2631.namprd15.prod.outlook.com (2603:10b6:a03:152::24) x-ms-exchange-messagesentrepresentingtype: 1 x-originating-ip: [2620:10d:c090:180::779] x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: 78ee93fc-5ba2-465e-eecd-08d6d959380d x-microsoft-antispam: BCL:0;PCL:0;RULEID:(2390118)(7020095)(4652040)(8989299)(4534185)(4627221)(201703031133081)(201702281549075)(8990200)(5600141)(711020)(4605104)(2017052603328)(7193020);SRVR:BYAPR15MB3272; x-ms-traffictypediagnostic: BYAPR15MB3272: x-ms-exchange-purlcount: 1 x-microsoft-antispam-prvs: x-ms-oob-tlc-oobclassifiers: OLM:6108; x-forefront-prvs: 0038DE95A2 x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(7916004)(396003)(136003)(39860400002)(366004)(376002)(346002)(189003)(199004)(71190400001)(71200400001)(6116002)(86362001)(1076003)(2906002)(33716001)(256004)(14444005)(5660300002)(6916009)(53936002)(305945005)(7736002)(4326008)(25786009)(66476007)(64756008)(6306002)(52116002)(102836004)(386003)(6246003)(68736007)(316002)(8936002)(81156014)(81166006)(486006)(54906003)(46003)(11346002)(446003)(476003)(14454004)(478600001)(99286004)(966005)(186003)(6506007)(76176011)(53546011)(229853002)(6436002)(8676002)(6486002)(66556008)(73956011)(66446008)(66946007)(6512007)(9686003)(33656002)(37363001);DIR:OUT;SFP:1102;SCL:1;SRVR:BYAPR15MB3272;H:BYAPR15MB2631.namprd15.prod.outlook.com;FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;MX:1;A:1; received-spf: None (protection.outlook.com: fb.com does not designate permitted sender hosts) x-ms-exchange-senderadcheck: 1 x-microsoft-antispam-message-info: vg3BzHvxkPXFjgIqSEWTEWzw+8MlX5xUwCYvsuInvLQfXx+/XVVscPghTPTch3GHsda0ll4OToxi2aCY3JJVhc3JeqaBGfRctXbz21+K9sWPHh2GlXNiYDMlVJbuwMcSRtfhthOdx2waa8KnzMp9t6WLBrhgXEgETgRrRiPfvuVrLYZLGslGhY8XRGsAxn1jYGfFESRqm9iSU9uyHOQjeJ+KoCeqozrsIyl0r9TTzgZIh7HEH8+5b7SigLRNvPgwctR9STTOnWafT1sfXRFlJh7jrTWBoP8rmKrIUCiKzqqws5eTg54h2SI98zYAne1dZz+IUCU6ViBpzDczIrtjJEHV0ML7ycRHBpxH04y9TBZpPAxUNz3d6I1piNGvAD63CXQYT9tsSVpCv1KRMktImcqs0l0cx8pqb9D2p29EuHo= Content-Type: text/plain; charset="us-ascii" Content-ID: <315A17B3378CFB4999879700E65EF6B5@namprd15.prod.outlook.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-MS-Exchange-CrossTenant-Network-Message-Id: 78ee93fc-5ba2-465e-eecd-08d6d959380d X-MS-Exchange-CrossTenant-originalarrivaltime: 15 May 2019 17:17:33.8955 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 8ae927fe-1255-47a7-a2af-5f3a069daaa2 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR15MB3272 X-OriginatorOrg: fb.com X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-05-15_11:,, 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=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=495 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1905150104 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: On Wed, May 15, 2019 at 01:11:46PM +0530, Anshuman Khandual wrote: >=20 >=20 > On 05/15/2019 05:21 AM, Roman Gushchin wrote: > > __vunmap() calls find_vm_area() twice without an obvious reason: > > first directly to get the area pointer, second indirectly by calling > > vm_remove_mappings()->remove_vm_area(), which is again searching > > for the area. > >=20 > > To remove this redundancy, let's split remove_vm_area() into > > __remove_vm_area(struct vmap_area *), which performs the actual area > > removal, and remove_vm_area(const void *addr) wrapper, which can > > be used everywhere, where it has been used before. Let's pass > > a pointer to the vm_area instead of vm_struct to vm_remove_mappings(), > > so it can pass it to __remove_vm_area() and avoid the redundant area > > lookup. > >=20 > > On my test setup, I've got 5-10% speed up on vfree()'ing 1000000 > > of 4-pages vmalloc blocks. > >=20 > > Perf report before: > > 29.44% cat [kernel.kallsyms] [k] free_unref_page > > 11.88% cat [kernel.kallsyms] [k] find_vmap_area > > 9.28% cat [kernel.kallsyms] [k] __free_pages > > 7.44% cat [kernel.kallsyms] [k] __slab_free > > 7.28% cat [kernel.kallsyms] [k] vunmap_page_range > > 4.56% cat [kernel.kallsyms] [k] __vunmap > > 3.64% cat [kernel.kallsyms] [k] __purge_vmap_area_lazy > > 3.04% cat [kernel.kallsyms] [k] __free_vmap_area > >=20 > > Perf report after: > > 32.41% cat [kernel.kallsyms] [k] free_unref_page > > 7.79% cat [kernel.kallsyms] [k] find_vmap_area > > 7.40% cat [kernel.kallsyms] [k] __slab_free > > 7.31% cat [kernel.kallsyms] [k] vunmap_page_range > > 6.84% cat [kernel.kallsyms] [k] __free_pages > > 6.01% cat [kernel.kallsyms] [k] __vunmap > > 3.98% cat [kernel.kallsyms] [k] smp_call_function_single > > 3.81% cat [kernel.kallsyms] [k] __purge_vmap_area_lazy > > 2.77% cat [kernel.kallsyms] [k] __free_vmap_area > >=20 > > Signed-off-by: Roman Gushchin > > Cc: Johannes Weiner > > Cc: Matthew Wilcox > > Cc: Vlastimil Babka > > --- > > mm/vmalloc.c | 52 +++++++++++++++++++++++++++++----------------------- > > 1 file changed, 29 insertions(+), 23 deletions(-) > >=20 > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > > index c42872ed82ac..8d4907865614 100644 > > --- a/mm/vmalloc.c > > +++ b/mm/vmalloc.c > > @@ -2075,6 +2075,22 @@ struct vm_struct *find_vm_area(const void *addr) > > return NULL; > > } > > =20 > > +static struct vm_struct *__remove_vm_area(struct vmap_area *va) > > +{ > > + struct vm_struct *vm =3D va->vm; > > + > > + spin_lock(&vmap_area_lock); > > + va->vm =3D NULL; > > + va->flags &=3D ~VM_VM_AREA; > > + va->flags |=3D VM_LAZY_FREE; > > + spin_unlock(&vmap_area_lock); > > + > > + kasan_free_shadow(vm); > > + free_unmap_vmap_area(va); > > + > > + return vm; > > +} > > + > > /** > > * remove_vm_area - find and remove a continuous kernel virtual area > > * @addr: base address > > @@ -2087,26 +2103,14 @@ struct vm_struct *find_vm_area(const void *addr= ) > > */ > > struct vm_struct *remove_vm_area(const void *addr) > > { > > + struct vm_struct *vm =3D NULL; > > struct vmap_area *va; > > =20 > > - might_sleep(); >=20 > Is not this necessary any more ? We've discussed it here: https://lkml.org/lkml/2019/4/17/1098 . Tl;dr it's not that useful. >=20 > > - > > va =3D find_vmap_area((unsigned long)addr); > > - if (va && va->flags & VM_VM_AREA) { > > - struct vm_struct *vm =3D va->vm; > > - > > - spin_lock(&vmap_area_lock); > > - va->vm =3D NULL; > > - va->flags &=3D ~VM_VM_AREA; > > - va->flags |=3D VM_LAZY_FREE; > > - spin_unlock(&vmap_area_lock); > > - > > - kasan_free_shadow(vm); > > - free_unmap_vmap_area(va); > > + if (va && va->flags & VM_VM_AREA) > > + vm =3D __remove_vm_area(va); > > =20 > > - return vm; > > - } > > - return NULL; > > + return vm; > > } >=20 > Other callers of remove_vm_area() cannot use __remove_vm_area() directly = as well > to save a look up ? >=20 I'll take a look. Good idea, thanks! Roman