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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E7934CA1002 for ; Thu, 4 Sep 2025 12:39:21 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 50AEC6B000D; Thu, 4 Sep 2025 08:39:21 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4B4AA6B000E; Thu, 4 Sep 2025 08:39:21 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3A32B6B0011; Thu, 4 Sep 2025 08:39:21 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 26D486B000D for ; Thu, 4 Sep 2025 08:39:21 -0400 (EDT) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id CC40984522 for ; Thu, 4 Sep 2025 12:39:20 +0000 (UTC) X-FDA: 83851523280.25.E433AFB Received: from fra-out-008.esa.eu-central-1.outbound.mail-perimeter.amazon.com (fra-out-008.esa.eu-central-1.outbound.mail-perimeter.amazon.com [35.158.23.94]) by imf21.hostedemail.com (Postfix) with ESMTP id 56A051C000F for ; Thu, 4 Sep 2025 12:39:18 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=amazon.de header.s=amazoncorp2 header.b=Tvlxv7OT; spf=pass (imf21.hostedemail.com: domain of "prvs=335a05013=suschako@amazon.de" designates 35.158.23.94 as permitted sender) smtp.mailfrom="prvs=335a05013=suschako@amazon.de"; dmarc=pass (policy=quarantine) header.from=amazon.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1756989558; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=ULScby5e7nfE21eIVPMtirUeTHzPiyrQ91q0FcQlkHM=; b=e59gwnnniSwUvIs3dvLeQl1qvN7ljVqVPnkTndM1/UVQFV9cHlKFP4N0AcWf832Vqmro/6 6Dzg8ftdODz6T+HN4EVrQfBO2e3NU7ElNum8ut8kARDoEtMkzDwSz0hN4jk+rcisN1SDFL 9vjcPKOdAiYluVPtYUpnzBq2Z6oAjJI= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=amazon.de header.s=amazoncorp2 header.b=Tvlxv7OT; spf=pass (imf21.hostedemail.com: domain of "prvs=335a05013=suschako@amazon.de" designates 35.158.23.94 as permitted sender) smtp.mailfrom="prvs=335a05013=suschako@amazon.de"; dmarc=pass (policy=quarantine) header.from=amazon.de ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1756989558; a=rsa-sha256; cv=none; b=4K8ATV/57im59V06MLAEDCIZHB7N/hs8j4DOsJturXuyltxNxUyFS39MvLUMF0Lk2Mkts9 MprJXVN3HaYZC9Myf3dOv9H5E/Zp/GHIZhO7CTnfrb/jKI4MlFkaAm6nUJZNvI2FmWTzhX xrbTVYFL+ML3N915+W+Cac0aMaCCAsg= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.de; i=@amazon.de; q=dns/txt; s=amazoncorp2; t=1756989558; x=1788525558; h=from:to:cc:date:message-id:references:in-reply-to: mime-version:content-transfer-encoding:subject; bh=ULScby5e7nfE21eIVPMtirUeTHzPiyrQ91q0FcQlkHM=; b=Tvlxv7OT5/R+n/tjOWA08AZomPW/t4bpMORNKodGH64P6yckaE02+9Fm lgrL2JyNEYG6sAv+GB4/xY2oyRgB1HLOU1DQhOpv9j8HdJDaUNw/SRIkm LeAQHmatYGEbUhhk45YGG+KzdfXi4x68uh4dxz8dRj1Z8BymbjBw3u+tF iEDLuOSd2qaFyuSecsMYMUEUaSycESeFm1XTjcUxmn2GU8d+/Uv25RdAu LZ7nkOsXZxN377w4EhEt4nIUv+ZNkDBweQcckCwAq2tAEgtI/JII1eFju puLPx5RXsMtvySHQvTTzenuJ2FsFPKEK0bQNQcwy9tEsf//A0m5T4oyfW Q==; X-CSE-ConnectionGUID: zSYct0lzSkaIIBnxJlsWUQ== X-CSE-MsgGUID: siHY+fGUQ/eEuX1zssW6cw== X-IronPort-AV: E=Sophos;i="6.18,214,1751241600"; d="scan'208";a="1639693" Subject: Re: Bug: Performance regression in 1013af4f585f: mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race Thread-Topic: Bug: Performance regression in 1013af4f585f: mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race Received: from ip-10-6-3-216.eu-central-1.compute.internal (HELO smtpout.naws.eu-central-1.prod.farcaster.email.amazon.dev) ([10.6.3.216]) by internal-fra-out-008.esa.eu-central-1.outbound.mail-perimeter.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Sep 2025 12:39:08 +0000 Received: from EX19MTAEUC002.ant.amazon.com [54.240.197.228:13862] by smtpin.naws.eu-central-1.prod.farcaster.email.amazon.dev [10.0.43.161:2525] with esmtp (Farcaster) id 2da87af0-5385-40d0-9937-3670b0b57a6f; Thu, 4 Sep 2025 12:39:08 +0000 (UTC) X-Farcaster-Flow-ID: 2da87af0-5385-40d0-9937-3670b0b57a6f Received: from EX19D024EUA001.ant.amazon.com (10.252.50.75) by EX19MTAEUC002.ant.amazon.com (10.252.51.181) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.2562.20; Thu, 4 Sep 2025 12:39:08 +0000 Received: from EX19D024EUA004.ant.amazon.com (10.252.50.30) by EX19D024EUA001.ant.amazon.com (10.252.50.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.2562.20; Thu, 4 Sep 2025 12:39:07 +0000 Received: from EX19D024EUA004.ant.amazon.com ([fe80::4608:828c:c80b:ca72]) by EX19D024EUA004.ant.amazon.com ([fe80::4608:828c:c80b:ca72%3]) with mapi id 15.02.2562.020; Thu, 4 Sep 2025 12:39:07 +0000 From: "Uschakow, Stanislav" To: David Hildenbrand , Jann Horn CC: "linux-mm@kvack.org" , "trix@redhat.com" , "ndesaulniers@google.com" , "nathan@kernel.org" , "akpm@linux-foundation.org" , "muchun.song@linux.dev" , "mike.kravetz@oracle.com" , "lorenzo.stoakes@oracle.com" , "liam.howlett@oracle.com" , "osalvador@suse.de" , "vbabka@suse.cz" , "stable@vger.kernel.org" , "gregkh@linuxfoundation.org" , "linux-kernel@vger.kernel.org" Thread-Index: AQHcGOKArPRLx5Gss0qhHb9N9ZVPl7R+LN+AgAAH1gCABJSBfQ== Date: Thu, 4 Sep 2025 12:39:07 +0000 Message-ID: <355102b559a747fe9a09142d46852551@amazon.de> References: <4d3878531c76479d9f8ca9789dc6485d@amazon.de> ,<2dcf12d0-e29c-4c9b-aeac-a0b803d2c2fd@redhat.com> In-Reply-To: <2dcf12d0-e29c-4c9b-aeac-a0b803d2c2fd@redhat.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.252.51.153] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 X-Stat-Signature: 36ow3oj59f57qp6zr3u9rx9a6j6r4hxk X-Rspam-User: X-Rspamd-Queue-Id: 56A051C000F X-Rspamd-Server: rspam05 X-HE-Tag: 1756989558-589403 X-HE-Meta: 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 zMGlz+XC 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 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: List-Subscribe: List-Unsubscribe: SGkgRGF2aWQsDQoNCj4gRnJvbTogRGF2aWQgSGlsZGVuYnJhbmQgPGRhdmlkQHJlZGhhdC5jb20+ DQo+IFNlbnQ6IE1vbmRheSwgU2VwdGVtYmVyIDEsIDIwMjUgMToyNiBQTQ0KPiBUbzogSmFubiBI b3JuOyBVc2NoYWtvdywgU3RhbmlzbGF2DQo+IENjOiBsaW51eC1tbUBrdmFjay5vcmc7IHRyaXhA cmVkaGF0LmNvbTsgbmRlc2F1bG5pZXJzQGdvb2dsZS5jb207IG5hdGhhbkBrZXJuZWwub3JnOyBh a3BtQGxpbnV4LWZvdW5kYXRpb24ub3JnOyBtdWNodW4uc29uZ0BsaW51eC5kZXY7IG1pa2Uua3Jh dmV0ekBvcmFjbGUuY29tOyBsb3JlbnpvLnN0b2FrZXNAb3JhY2xlLmNvbTsgbGlhbS5ob3dsZXR0 QG9yYWNsZS5jb207IG9zYWx2YWRvckBzdXNlLmRlOyB2YmFia2FAc3VzZS5jejsgc3RhYmxlQHZn ZXIua2VybmVsLm9yZw0KPiBTdWJqZWN0OiBSRTogW0VYVEVSTkFMXSBCdWc6IFBlcmZvcm1hbmNl IHJlZ3Jlc3Npb24gaW4gMTAxM2FmNGY1ODVmOiBtbS9odWdldGxiOiBmaXggaHVnZV9wbWRfdW5z aGFyZSgpIHZzIEdVUC1mYXN0IHJhY2UNCj4gwqAgICANCj4gQ0FVVElPTjogVGhpcyBlbWFpbCBv cmlnaW5hdGVkIGZyb20gb3V0c2lkZSBvZiB0aGUgb3JnYW5pemF0aW9uLiBEbyBub3QgY2xpY2sg bGlua3Mgb3Igb3BlbiBhdHRhY2htZW50cyB1bmxlc3MgeW91IGNhbiBjb25maXJtIHRoZSBzZW5k ZXIgYW5kIGtub3cgdGhlIGNvbnRlbnQgaXMgc2FmZS4NCj4gDQo+IA0KPiANCj4gT24gMDEuMDku MjUgMTI6NTgsIEphbm4gSG9ybiB3cm90ZToNCj4gPiBIaSENCj4gPg0KPiA+IE9uIEZyaSwgQXVn IDI5LCAyMDI1IGF0IDQ6MzDigK9QTSBVc2NoYWtvdywgU3RhbmlzbGF2IDxzdXNjaGFrb0BhbWF6 b24uZGU+IHdyb3RlOg0KPiA+PiBXZSBoYXZlIG9ic2VydmVkIGEgaHVnZSBsYXRlbmN5IGluY3Jl YXNlIHVzaW5nIGBmb3JrKClgIGFmdGVyIGluZ2VzdGluZyB0aGUgQ1ZFLTIwMjUtMzgwODUgZml4 IHdoaWNoIGxlYWRzIHRvIHRoZSBjb21taXQgYDEwMTNhZjRmNTg1ZjogbW0vaHVnZXRsYjogZml4 IGh1Z2VfcG1kX3Vuc2hhcmUoKSB2cyBHVVAtZmFzdCByYWNlYC4gT24gbGFyZ2UgbWFjaGluZXMg d2l0aCAxLjVUQiBvZiBtZW1vcnkgd2l0aCAxOTYgY29yZXMsIHdlIGlkZW50aWZpZWQgIG1tYXBw aW5nIG9mIDEuMlRCIG9mIHNoYXJlZCBtZW1vcnkgYW5kIGZvcmtpbmcgaXRzZWxmIGRvemVucyBv ciBodW5kcmVkcyBvZiB0aW1lcyB3ZSBzZWUgYSBpbmNyZWFzZSBvZiBleGVjdXRpb24gdGltZXMg b2YgYSBmYWN0b3Igb2YgNC4gVGhlIHJlcHJvZHVjZXIgaXMgYXQgdGhlIGVuZCBvZiB0aGUgZW1h aWwuDQo+ID4NCj4gPiBZZWFoLCBldmVyeSAxRyB2aXJ0dWFsIGFkZHJlc3MgcmFuZ2UgeW91IHVu c2hhcmUgb24gdW5tYXAgd2lsbCBkbyBhbg0KPiA+IGV4dHJhIHN5bmNocm9ub3VzIElQSSBicm9h ZGNhc3QgdG8gYWxsIENQVSBjb3Jlcywgc28gaXQncyBub3QgdmVyeQ0KPiA+IHN1cnByaXNpbmcg dGhhdCBkb2luZyB0aGlzIHdvdWxkIGJlIGEgYml0IHNsb3cgb24gYSBtYWNoaW5lIHdpdGggMTk2 DQo+ID4gY29yZXMuDQo+IA0KPiBXaGF0IGlzIHRoZSB1c2UgY2FzZSBmb3IgdGhpcyBleHRyZW1l IHVzYWdlIG9mIGZvcmsoKSBpbiB0aGF0IGNvbnRleHQ/DQo+IElzIGl0IGp1c3Qgc29tZXRoaW5n IHBlb3BsZSBub3RpY2VkIGFuZCBpdCdzIHN1Ym9wdGltYWwsIG9yIGlzIHRoaXMgYQ0KPiByZWFs IHByb2JsZW0gZm9yIHNvbWUgdXNlIGNhc2VzPw0KPiANCg0KWWVzLCB3ZSBoYXZlIGN1c3RvbWVy IHJlcG9ydGluZyBodWdlIHBlcmZvcm1hbmNlIHJlZ3Jlc3Npb25zIG9uIHRoZWlyIHdvcmtsb2Fk cy4gSSBkb24ndCBrbm93IHRoZSBzb2Z0d2FyZSBhcmNoaXRlY3R1cmUgb3IgYWN0dWFsIHVzZSBj YXNlIGZvciB0aGVpciBhcHBsaWNhdGlvbiB0aG91Z2guIEEgZXhlY3V0aW9uIHRpbWUgaW5jcmVh c2Ugb2YgYXQgbGVhc3QgYSBmYWN0b3Igb2YgNCBpcyBub3RpY2VhYmxlIGV2ZW4gd2l0aCBmZXcg Zm9ya3MoKSBvbiB0aG9zZSBtYWNoaW5lcy4NCg0KPiAtLQ0KPiBDaGVlcnMNCj4gDQo+IERhdmlk IC8gZGhpbGRlbmINCg0KDQpUaGFua3MNCg0KU3RhbmlzbGF2DQoNCiAgICAKCgoKQW1hem9uIFdl YiBTZXJ2aWNlcyBEZXZlbG9wbWVudCBDZW50ZXIgR2VybWFueSBHbWJIClRhbWFyYS1EYW56LVN0 ci4gMTMKMTAyNDMgQmVybGluCkdlc2NoYWVmdHNmdWVocnVuZzogQ2hyaXN0aWFuIFNjaGxhZWdl ciwgSm9uYXRoYW4gV2Vpc3MKRWluZ2V0cmFnZW4gYW0gQW10c2dlcmljaHQgQ2hhcmxvdHRlbmJ1 cmcgdW50ZXIgSFJCIDI1Nzc2NCBCClNpdHo6IEJlcmxpbgpVc3QtSUQ6IERFIDM2NSA1MzggNTk3 Cg==