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Shutemov" CC: "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "oleg@redhat.com" , "rostedt@goodmis.org" , "mhiramat@kernel.org" , "matthew.wilcox@oracle.com" , "kirill.shutemov@linux.intel.com" , Kernel Team Subject: Re: [PATCH v4 3/5] mm, thp: introduce FOLL_SPLIT_PMD Thread-Topic: [PATCH v4 3/5] mm, thp: introduce FOLL_SPLIT_PMD Thread-Index: AQHVIhGahpwtXNAKfka+bawgVMaQOKamGd4AgAAXqYA= Date: Fri, 21 Jun 2019 14:08:44 +0000 Message-ID: <6D00E9F1-A81D-44B8-9504-3B7B440CF093@fb.com> References: <20190613175747.1964753-1-songliubraving@fb.com> <20190613175747.1964753-4-songliubraving@fb.com> <20190621124402.z4l67ck4vr5g7xe3@box> In-Reply-To: <20190621124402.z4l67ck4vr5g7xe3@box> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-mailer: Apple Mail (2.3445.104.11) x-originating-ip: [2620:10d:c090:180::1:ed23] x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: 4ede19af-12c0-47b3-ac9e-08d6f651f8b0 x-microsoft-antispam: BCL:0;PCL:0;RULEID:(2390118)(7020095)(4652040)(8989299)(4534185)(4627221)(201703031133081)(201702281549075)(8990200)(5600148)(711020)(4605104)(1401327)(2017052603328)(7193020);SRVR:MWHPR15MB1373; x-ms-traffictypediagnostic: MWHPR15MB1373: x-microsoft-antispam-prvs: x-ms-oob-tlc-oobclassifiers: OLM:5516; x-forefront-prvs: 0075CB064E x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(396003)(366004)(346002)(39860400002)(376002)(136003)(199004)(189003)(50226002)(476003)(53546011)(6506007)(11346002)(446003)(486006)(102836004)(186003)(64756008)(14454004)(66476007)(76116006)(76176011)(46003)(25786009)(66556008)(66446008)(2616005)(316002)(8936002)(36756003)(478600001)(6246003)(73956011)(86362001)(4326008)(5660300002)(99286004)(6436002)(229853002)(66946007)(6512007)(6486002)(81166006)(81156014)(8676002)(256004)(33656002)(14444005)(4744005)(6916009)(53936002)(6116002)(54906003)(68736007)(305945005)(57306001)(7736002)(2906002)(71190400001)(71200400001);DIR:OUT;SFP:1102;SCL:1;SRVR:MWHPR15MB1373;H:MWHPR15MB1165.namprd15.prod.outlook.com;FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;A:1;MX: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: yFcG8VFYpoeh1scsxtFjPMyNxBDkkzIuM3W568+JvDBmCmVe4DJM5XOGBxDVpl2hVjW8f54RMoAQ9aPrrx3VU17YYBT0XjSUOq1mRd3KAm4ZaaKDWFipSfowzsBGeVIQ177W1fL5uVGWhIO9cjMVBCFBdKXFbhNisiwW2viTGlns3l2OicExzW2lhiV5B+P8/EZcg3pewgiQ6WAV4MFxXN3Ub0BYjJpGg+irn58ZhG4lRov21ITRnBxPRamlb4s5XAw4Kp+Qf9yUw15qycxIaol9WJrRlxCOmiS8+7RJrBycs9IvRvoqL1k8owN8GGCl8ehZv3PZ8RBYJMctwWbOE/c16BfFqAqIh8VyG/m5u5sOCteIzJCnUPOi1MZaA0vt+NIAbFkCArbchuQxu/bMWie6r4Jm0zmGKltYVTEdCLU= Content-Type: text/plain; charset="us-ascii" Content-ID: <8C7F22507F1F2648A13AD376EE5EF553@namprd15.prod.outlook.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-MS-Exchange-CrossTenant-Network-Message-Id: 4ede19af-12c0-47b3-ac9e-08d6f651f8b0 X-MS-Exchange-CrossTenant-originalarrivaltime: 21 Jun 2019 14:08:44.3364 (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-CrossTenant-userprincipalname: songliubraving@fb.com X-MS-Exchange-Transport-CrossTenantHeadersStamped: MWHPR15MB1373 X-OriginatorOrg: fb.com X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-06-21_10:,, 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=657 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906210118 X-FB-Internal: deliver Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Jun 21, 2019, at 5:44 AM, Kirill A. Shutemov wr= ote: >=20 > On Thu, Jun 13, 2019 at 10:57:45AM -0700, Song Liu wrote: >> @@ -419,6 +419,11 @@ static struct page *follow_pmd_mask(struct vm_area_= struct *vma, >> put_page(page); >> if (pmd_none(*pmd)) >> return no_page_table(vma, flags); >> + } else { /* flags & FOLL_SPLIT_PMD */ >> + spin_unlock(ptl); >> + ret =3D 0; >> + split_huge_pmd(vma, pmd, address); >> + pte_alloc(mm, pmd); >=20 > pte_alloc() can fail and the failure should be propogated to the caller. Good catch! Fixing it now.=20 Thanks, Song=