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charset="us-ascii" Content-ID: <7F82A9FCD04DFA4C86D548276E455AB0@namprd10.prod.outlook.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: SN6PR10MB3022.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 5378b250-e0e6-42dc-035a-08d9e1b3206d X-MS-Exchange-CrossTenant-originalarrivaltime: 27 Jan 2022 16:36:10.1078 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: 1BzUw6tXIMx87irCPgxPmqPkpait3OdYMnbMKwMWJhvZqg9e+1LGoxz06dVpbQ1sD1Ln30ESa8XndaFOlj8S0w== X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR10MB2742 X-Proofpoint-Virus-Version: vendor=nai engine=6300 definitions=10239 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 mlxscore=0 malwarescore=0 spamscore=0 phishscore=0 suspectscore=0 adultscore=0 mlxlogscore=811 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2201110000 definitions=main-2201270100 X-Proofpoint-GUID: v91dZw3i4BOEG7qXIPxo3Ts0KjEfdWAb X-Proofpoint-ORIG-GUID: v91dZw3i4BOEG7qXIPxo3Ts0KjEfdWAb Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Vlastimil Babka [220120 12:06]: > On 1/20/22 16:54, Matthew Wilcox wrote: > > On Thu, Jan 20, 2022 at 04:06:21PM +0100, Vlastimil Babka wrote: > >> On 12/1/21 15:30, Liam Howlett wrote: > >> > From: "Matthew Wilcox (Oracle)" > >> >=20 > >> > Use the maple tree or VMA iterator instead. This is faster and will > >> > allow us to shrink the VMA. > >> >=20 > >> > Signed-off-by: Matthew Wilcox (Oracle) > >> > Signed-off-by: Liam R. Howlett > >>=20 > >> Acked-by: Vlastimil Babka > >>=20 > >> But I think some fixup needed: > >>=20 > >> > @@ -1456,12 +1458,14 @@ void exit_mmap(struct mm_struct *mm) > >> > =20 > >> > mm->total_vm =3D 0; > >> > =20 > >> > - while ((vma =3D mm->mmap)) { > >> > - mm->mmap =3D vma->vm_next; > >> > + mmap_write_lock(mm); > >>=20 > >> If locking was missing, should have been added sooner than now? > >=20 > > I don't think so? This is the exit_mmap() path, so we know nobody > > has access to the mm. We didn't need to hold the lock at this point > > before, but now for_each_vma() will check we're holding the mmap_lock. >=20 > It has crossed my mind that it is there to make asserts happy, in which c= ase > a clarifying comment would be useful. I will add the comment. >=20 > >> > + for_each_vma(vmi, vma) { > >> > delete_vma_from_mm(vma); > >> > delete_vma(mm, vma); > >> > cond_resched(); > >> > } > >> > + __mt_destroy(&mm->mm_mt); > >>=20 > >> And this at the point mm_mt was added? > >=20 > > You mean we should have been calling __mt_destroy() earlier in the > > patch series? >=20 > Yeah. >=20 > > Umm ... I'll defer to Liam on that one. Yes, I will move this to the correct patch.=