From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4263D3B42C4; Wed, 9 Sep 2026 23:40:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788997249; cv=none; b=X/gVOaydCyIklUaUTGttZnfyXWpw7hoG//nzarMUsZ2niOSiW6oltqp3jGSCAeFWIFf+tqziPFmQHlFufhzJMBaB+hQNVXd3suWJ/MhoswwM9JkaCU5ZwsMKUo4S1jxcqZXAyS1/35MRuDTbBzQtdYRtfhMLAcAjjOHTDn39/yU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788997249; c=relaxed/simple; bh=pQ2hvIBJ7r7iLugleg/hyDooi3Ia5TyFoTIhtFAkIq8=; h=Date:To:From:Subject:Message-Id; b=NKANaE/jRLPpnhULqx3201y8nitcxHue2fdiNrsDDqdO2EHuvouY3i2LuzmN0G9U9HBWF4yBs5EGlrak4ti9HFa4wUYwDcsRMMsBh+twLUxkuQGo+mdFdmuI83uU4aIOvcShZOmMKfVTobRopc+U9bUaojIA5PSFdFN3GQ9TMx0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=j+8n/MlX; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="j+8n/MlX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A37521F000FF; Wed, 9 Sep 2026 23:40:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1788997247; bh=ylzxcwrCMzhtS5T660JDDDgW7skGgyEiHYIa8sch4so=; h=Date:To:From:Subject; b=j+8n/MlX3fcv83puqbQ97f/c2+q4kMVhGvsFTxcQdpVxXnXmHlc0UQgNn541ZM0eX k8IBbmBrXqGVEgpU4/kLzXMwUfiSg0VU4PIiBFjr1GQsJ66+p40xRryThwi60ueNC5 aZIsoWnJaBc7FadH5U/Z6JCffptWPVGwjg4a1wC8= Date: Wed, 09 Sep 2026 16:40:47 -0700 To: mm-commits@vger.kernel.org,vbabka@kernel.org,vannapurve@google.com,surenb@google.com,stable@vger.kernel.org,si.yanteng@linux.dev,shakeel.butt@linux.dev,rppt@kernel.org,roman.gushchin@linux.dev,rientjes@google.com,peterx@redhat.com,osalvador@suse.de,nphamcs@gmail.com,muchun.song@linux.dev,mhocko@kernel.org,mawupeng1@huawei.com,louhongxiang@huawei.com,ljs@kernel.org,linmiaohe@huawei.com,liam@infradead.org,jthoughton@google.com,joshua.hahnjy@gmail.com,hannes@cmpxchg.org,fvdl@google.com,dzm91@hust.edu.cn,david@kernel.org,corbet@lwn.net,alexs@kernel.org,ackerleytng@google.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-hugetlb-return-enospc-on-memcg-charge-failure.patch added to mm-unstable branch Message-Id: <20260909234047.A37521F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm: hugetlb: return -ENOSPC on memcg charge failure has been added to the -mm mm-unstable branch. Its filename is mm-hugetlb-return-enospc-on-memcg-charge-failure.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-hugetlb-return-enospc-on-memcg-charge-failure.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Ackerley Tng Subject: mm: hugetlb: return -ENOSPC on memcg charge failure Date: Wed, 09 Sep 2026 10:11:00 -0700 Patch series "Fix bugs in HugeTLB allocation when mem_cgroup_charge_hugetlb() fails", v2. In hugetlb_alloc_folio(), when mem_cgroup_charge_hugetlb() fails, there are 2 issues: 1. free_huge_folio() expects a non-refcounted folio and will VM_BUG_ON_FOLIO(). 2. -ENOMEM is returned, causing an infinite loop retrying the fault. This patch (of 2): When mem_cgroup_charge_hugetlb() fails with -ENOMEM, alloc_hugetlb_folio() currently propagates this error. This results in the page fault handler returning VM_FAULT_OOM. Because HugeTLB allocations are high-order and use __GFP_RETRY_MAYFAIL, they bypass the OOM killer. Returning VM_FAULT_OOM to the #PF handler without triggering the OOM killer (or having it make progress) leads to an infinite loop of retrying the fault. Avoid this loop by returning -ENOSPC when charging fails, which maps to VM_FAULT_SIGBUS, terminating the process cleanly. Make mem_cgroup_charge_hugetlb() fault handling use a common error handling path, the same handling used for hugetlb_cgroup_uncharge_cgroup{,_rsvd}(), which also don't trigger the OOM killer and hence opt to terminate the process with a SIGBUS. Link: https://lore.kernel.org/20260909-hugetlb-alloc-folio-memcg-charge-error-handling-v2-1-4b4a8a19a7f7@google.com Fixes: 991135774c0e0 ("memcg/hugetlb: introduce mem_cgroup_charge_hugetlb") Signed-off-by: Ackerley Tng Reviewed-by: Muchun Song Reviewed-by: Joshua Hahn Cc: Alex Shi Cc: David Hildenbrand Cc: David Rientjes Cc: Dongliang Mu Cc: Frank van der Linden Cc: Hongxiang Lou Cc: James Houghton Cc: Johannes Weiner Cc: Jonathan Corbet Cc: Liam R. Howlett Cc: Lorenzo Stoakes Cc: Ma Wupeng Cc: Miaohe Lin Cc: Michal Hocko Cc: Mike Rapoport Cc: Nhat Pham Cc: Oscar Salvador Cc: Peter Xu Cc: Roman Gushchin Cc: Shakeel Butt Cc: Suren Baghdasaryan Cc: Vishal Annapurve Cc: Vlastimil Babka Cc: Yanteng Si Cc: Signed-off-by: Andrew Morton --- mm/hugetlb.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/mm/hugetlb.c~mm-hugetlb-return-enospc-on-memcg-charge-failure +++ a/mm/hugetlb.c @@ -2851,7 +2851,6 @@ void wait_for_freed_hugetlb_folios(void) * * Return: A pointer to the allocated folio, or an ERR_PTR on failure. * -ENOSPC if cgroup charging fails or no folio is available. - * -ENOMEM if mem cgroup charging fails. */ struct folio *hugetlb_alloc_folio(struct hstate *h, struct mempolicy_interpreted *mpoli, u8 alloc_flags) @@ -2924,7 +2923,11 @@ struct folio *hugetlb_alloc_folio(struct * were committed to the folio and freeing the folio * would have cleared those up. */ - return ERR_PTR(ret); + /* + * Return -ENOSPC, since retrying the fault is futile: + * the OOM killer is not triggered for HugeTLB. + */ + return ERR_PTR(-ENOSPC); } return folio; _ Patches currently in -mm which might be from ackerleytng@google.com are mm-hugetlb-return-enospc-on-memcg-charge-failure.patch mm-hugetlb-drop-refcount-before-freeing-on-memcg-charge-failure.patch