From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794046826; b=GA6AkAjVvt2+Dfa0ysHUOmfplce1DxL9ChsqTDfa0Ckl+LPoCHa1mtKpiaeWWvffashP ytYReLf0n5OvwGKVK96on+4OHpJVc4QjYEhucn8nilFkuH+hPhTaYrSXHBVH2T8Niu6jK vM3aHQNDTyo4JEM4ulMqokuOhczX4VmbEvwdXjsvqc5rUEZezAUov7Efw9fU7h5LDCYbE 5/f2ui3ZqbTDoi7OK6W8C+h2VF1IVD4+1q0jJBHmVrNooAWA//Pn1kBdzvAYxghu/vFk2 lLuWWuythRi14N3MTy8nWytGbyWBpessJ1+vEol5fCldJKAtHGL4sAxaXeq3BuvysiA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794046826; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=Iy1L1PvNDCqykgODwwaxpnAJfm7vgBqMZOOlU5gERh0=; b=jCdtS8YlKjU2tLtF0HnV7xRcT/hihzn/5Nak235EtGJjh8/8eSyV8+cXnHafUav3L1um 8Wihcj3px+Wwu9RUqWWxF7KEMeNibzAC6zXZ6a0QkGXcn06Ik7olLbV4hyK3dNBYpagxt SQHOMCrQE581Gx7cKsWf/0Af5lc3Un6ltWKpUh8YGjJfR3BnQEbBES+JAHeyGXEbLPvyg RoQ1udyM3p2X9iFmtOGOisUMqgnSglQSsSjsP3IixcQbLH6VH9QanaMeBZoTuk85eCvOo +ex0U+nmgN8W222pS/epg7/TCqGh59LOQylJSocNtyP+zIt8nW46bPc9Qvye1Qyf9Yg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=evD28z2t; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 21F64606A33E for ; Sat, 7 Nov 2026 10:20:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=evD28z2t Received: by smtp.kernel.org (Postfix) with ESMTPSA id A46001F0089F; Sat, 7 Nov 2026 10:20:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794046826; bh=Iy1L1PvNDCqykgODwwaxpnAJfm7vgBqMZOOlU5gERh0=; h=From:To:Cc:Subject:Date; b=evD28z2tuJRgzanlWGdymm6ZD5xxa54u+SzN5Baw9XZyqSla/bcN9ME/6rCM7AGwy 6m1EDS5weIyu9P6nVcZ2VPncryoTSYcEHDV8i1TWoUmRUlTo1yACO79MeV7P8X037Q o98JSexyTrUlaCQqmgvT792VO5QyNJObeVp089FAGMfQhZVpXjmj5X0TDa2HVA/X+H Proo0PflWgIN0MQo7gzgMML20JwED0QBd458dnMilRgyhY8anMvdTHH2OpkLSrWsZK xReH43CEKtimJWyFLuz/ZBcl8AGLYfdG2emO88XncoRSGN45NX9wiim90BbWL6BsNN JNo9J9R8npwqA== From: Sasha Levin To: jinmengzhou22@gmail.com, zhoujinmeng@bytedance.com, akpm@linux-foundation.org, muchun.song@linux.dev, lihongfu@kylinos.cn, david@kernel.org, hannes@cmpxchg.org, mhocko@kernel.org, nphamcs@gmail.com, osalvador@suse.de, roman.gushchin@linux.dev, shakeel.butt@linux.dev Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] mm/hugetlb: charge folios to the target mm's memcg" failed to apply to 6.12-stable tree Date: Sat, 7 Nov 2026 05:20:23 -0500 Message-ID: <20261107052023-failed-6.12-c2deb1356d82@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.12-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y git checkout FETCH_HEAD git cherry-pick -x c2deb1356d82c9d54bd2fcf1241cc97eb66fd81f # git commit -s git send-email --to '' --in-reply-to '20261107052023-failed-6.12-c2deb1356d82@kernel.org' --subject-prefix 'PATCH 6.12.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From c2deb1356d82c9d54bd2fcf1241cc97eb66fd81f Mon Sep 17 00:00:00 2001 From: Jinmeng Zhou Date: Thu, 3 Sep 2026 15:50:48 +0800 Subject: [PATCH] mm/hugetlb: charge folios to the target mm's memcg HugeTLB folios are currently charged to the memcg of the allocating task. This gives the wrong result when a userfaultfd handler populates a HugeTLB VMA that belongs to another process. The UFFDIO_COPY ioctl operates on the userfaultfd context's mm, but get_mem_cgroup_from_current() charges the folio to the handler's memcg instead. This can be reproduced by placing the faulting process and its userfaultfd handler in different memory cgroups. Have the target process register a HugeTLB mapping with userfaultfd, trigger a missing fault, and let the handler resolve it with UFFDIO_COPY. The hugepage usage is then reported in the handler's memory.current instead of the target's. The generic userfaultfd population path avoids this problem by charging folios to dst_vma->vm_mm. Pass the target mm through hugetlb_alloc_folio() and charge the folio by using get_mem_cgroup_from_mm(). This preserves the existing charge timing and error handling while making HugeTLB userfaultfd population consistent with the generic path. Link: https://lore.kernel.org/20260903075048.3316-1-zhoujinmeng@bytedance.com Fixes: 8cba9576df60 ("hugetlb: memcg: account hugetlb-backed memory in memory controller") Signed-off-by: Jinmeng Zhou Signed-off-by: Andrew Morton Reviewed-by: Muchun Song Reviewed-by: Hongfu Li Cc: David Hildenbrand Cc: Johannes Weiner Cc: Michal Hocko Cc: Nhat Pham Cc: Oscar Salvador Cc: Roman Gushchin Cc: Shakeel Butt Cc: --- include/linux/hugetlb.h | 3 ++- include/linux/memcontrol.h | 8 +++++--- mm/hugetlb.c | 9 ++++++--- mm/memcontrol.c | 6 ++++-- 4 files changed, 17 insertions(+), 9 deletions(-) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 900c95e346b2e..80a5a03e9cee7 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -694,7 +694,8 @@ enum hugetlb_alloc_flag { #define HUGETLB_ALLOC_USE_GLOBAL_RESERVATIONS BIT(HUGETLB_ALLOC_USE_GLOBAL_RESERVATIONS_BIT) struct folio *hugetlb_alloc_folio(struct hstate *h, - struct mempolicy_interpreted *mpoli, u8 alloc_flags); + struct mempolicy_interpreted *mpoli, struct mm_struct *mm, + u8 alloc_flags); struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma, unsigned long addr, bool cow_from_owner); struct folio *alloc_hugetlb_folio_nodemask(struct hstate *h, int preferred_nid, diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index c799926435560..058ebd73ff160 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -647,7 +647,8 @@ static inline int mem_cgroup_charge(struct folio *folio, struct mm_struct *mm, return __mem_cgroup_charge(folio, mm, gfp); } -int mem_cgroup_charge_hugetlb(struct folio* folio, gfp_t gfp); +int mem_cgroup_charge_hugetlb(struct folio *folio, struct mm_struct *mm, + gfp_t gfp); int mem_cgroup_swapin_charge_folio(struct folio *folio, unsigned short id, struct mm_struct *mm, gfp_t gfp); @@ -1146,9 +1147,10 @@ static inline int mem_cgroup_charge(struct folio *folio, return 0; } -static inline int mem_cgroup_charge_hugetlb(struct folio* folio, gfp_t gfp) +static inline int mem_cgroup_charge_hugetlb(struct folio *folio, + struct mm_struct *mm, gfp_t gfp) { - return 0; + return 0; } static inline int mem_cgroup_swapin_charge_folio(struct folio *folio, diff --git a/mm/hugetlb.c b/mm/hugetlb.c index cdb7d8df666a7..c59ebbcf66845 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2844,6 +2844,7 @@ void wait_for_freed_hugetlb_folios(void) * hugetlb_alloc_folio - Allocate a hugetlb folio. * @h: Hugetlb state control block. * @mpoli: Interpreted memory policy to use for allocation. + * @mm: Memory descriptor of the allocation target. * @alloc_flags: Flags controlling the allocation behavior. * * Allocates a hugetlb folio and handles cgroup charging and global hstate @@ -2853,7 +2854,8 @@ void wait_for_freed_hugetlb_folios(void) * -ENOSPC if cgroup charging fails or no folio is available. */ struct folio *hugetlb_alloc_folio(struct hstate *h, - struct mempolicy_interpreted *mpoli, u8 alloc_flags) + struct mempolicy_interpreted *mpoli, struct mm_struct *mm, + u8 alloc_flags) { bool charge_hugetlb_cgroup_rsvd = alloc_flags & HUGETLB_ALLOC_CHARG_CGROUP_RSVD; @@ -2908,7 +2910,8 @@ struct folio *hugetlb_alloc_folio(struct hstate *h, spin_unlock_irq(&hugetlb_lock); - ret = mem_cgroup_charge_hugetlb(folio, gfp | __GFP_RETRY_MAYFAIL); + ret = mem_cgroup_charge_hugetlb(folio, mm, + gfp | __GFP_RETRY_MAYFAIL); /* * Unconditionally increment NR_HUGETLB here because if * mem_cgroup_charge_hugetlb failed, freeing the page will @@ -3051,7 +3054,7 @@ struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma, .nodemask = nodemask, }; - folio = hugetlb_alloc_folio(h, &mpoli, alloc_flags); + folio = hugetlb_alloc_folio(h, &mpoli, vma->vm_mm, alloc_flags); mpol_cond_put(mpol); diff --git a/mm/memcontrol.c b/mm/memcontrol.c index bd1e7e1544265..86ff580c70183 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5265,6 +5265,7 @@ int __mem_cgroup_charge(struct folio *folio, struct mm_struct *mm, gfp_t gfp) /** * mem_cgroup_charge_hugetlb - charge the memcg for a hugetlb folio * @folio: folio being charged + * @mm: mm context of the allocation target * @gfp: reclaim mode * * This function is called when allocating a huge page folio, after the page has @@ -5274,9 +5275,10 @@ int __mem_cgroup_charge(struct folio *folio, struct mm_struct *mm, gfp_t gfp) * Returns ENOMEM if the memcg is already full. * Returns 0 if either the charge was successful, or if we skip the charging. */ -int mem_cgroup_charge_hugetlb(struct folio *folio, gfp_t gfp) +int mem_cgroup_charge_hugetlb(struct folio *folio, struct mm_struct *mm, + gfp_t gfp) { - struct mem_cgroup *memcg = get_mem_cgroup_from_current(); + struct mem_cgroup *memcg = get_mem_cgroup_from_mm(mm); int ret = 0; /* -- 2.53.0