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Howlett" , "Nico Pache" , "Ryan Roberts" , "Dev Jain" , "Barry Song" , "Lance Yang" , "Usama Arif" , , , To: "Johannes Weiner" , "Lorenzo Stoakes (ARM)" From: "Zi Yan" X-Mailer: aerc 0.21.0 References: <20260730-add-gfp_account-to-xas_split_alloc-v2-0-5a56c2361d85@nvidia.com> <20260730-add-gfp_account-to-xas_split_alloc-v2-1-5a56c2361d85@nvidia.com> In-Reply-To: X-ClientProxiedBy: CH0PR07CA0011.namprd07.prod.outlook.com (2603:10b6:610:32::16) To IA0PR12MB8374.namprd12.prod.outlook.com (2603:10b6:208:40e::7) Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: IA0PR12MB8374:EE_|CY5PR12MB6298:EE_ X-MS-Office365-Filtering-Correlation-Id: 55d73992-3e95-4ed2-d39c-08def1703e4f X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|23010399003|1800799024|7416014|376014|56012099006|10067099003|11063799006|5023799004|4143699003|6133799003|22082099003|18002099003; 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Switch to folio's memcg at the >> beginning and switch back afterwards. > > I assume this is the only allocation? I guess in general it makes sense t= o have > the folio's memcg be active here regardless. > >> >> Suggested-by: Johannes Weiner >> Fixes: 6b24ca4a1a8d4 ("mm: Use multi-index entries in the page cache") > > Cc: stable? Like you said above, only xas_split_alloc() is affected. And we have not seen related workingset regression report (like what Johannes reported in commit 7b785645e8f13 ("mm: fix page cache convergence regression")). It might be OK to not backport. Johannes, what is your take on this? > >> Signed-off-by: Zi Yan > > Change seems reasonable overall. > > Acked-by: Lorenzo Stoakes (ARM) > >> --- >> mm/huge_memory.c | 20 ++++++++++++++++---- >> 1 file changed, 16 insertions(+), 4 deletions(-) >> >> diff --git a/mm/huge_memory.c b/mm/huge_memory.c >> index 04e8a6b553435..b9c2d8908e564 100644 >> --- a/mm/huge_memory.c >> +++ b/mm/huge_memory.c >> @@ -4063,34 +4063,42 @@ static int __folio_split(struct folio *folio, un= signed int new_order, >> XA_STATE(xas, &folio->mapping->i_pages, folio->index); >> struct folio *end_folio =3D folio_next(folio); >> bool is_anon =3D folio_test_anon(folio); >> + struct mem_cgroup *memcg, *old_memcg; >> struct address_space *mapping =3D NULL; >> struct anon_vma *anon_vma =3D NULL; >> int old_order =3D folio_order(folio); >> struct folio *new_folio, *next; >> int nr_shmem_dropped =3D 0; >> enum ttu_flags ttu_flags =3D 0; >> - int ret; >> pgoff_t end =3D 0; >> + int ret; >> >> VM_WARN_ON_ONCE_FOLIO(!folio_test_locked(folio), folio); >> VM_WARN_ON_ONCE_FOLIO(!folio_test_large(folio), folio); >> >> if (folio !=3D page_folio(split_at) || folio !=3D page_folio(lock_at))= { >> ret =3D -EINVAL; >> - goto out; >> + goto out_no_memcg; >> } >> >> if (new_order >=3D old_order) { >> ret =3D -EINVAL; >> - goto out; >> + goto out_no_memcg; >> } >> >> ret =3D folio_check_splittable(folio, new_order, split_type); >> if (ret) { >> VM_WARN_ONCE(ret =3D=3D -EINVAL, "Tried to split an unsplittable foli= o"); >> - goto out; >> + goto out_no_memcg; > > This function really badly needs splitting up and probably some cleanup.h= work :) You mean folio_check_splittable()? You want to move -EINVAL checks a separate one? --=20 Best Regards, Yan, Zi