From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qt1-f179.google.com (mail-qt1-f179.google.com [209.85.160.179]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3EBA8238C0D for ; Sun, 22 Feb 2026 08:49:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.179 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771750179; cv=none; b=knM8tb5Pr2VKC1HqTn/QXqOLKd5ShaUl1uqNhVqcUK7Z1BW1sEmJCgercfSMIh7y/XFEY/M7ctFg0mpYiFV2Mvp72WKDKDWETXq7ZNBeSBlgZE+ccHzQIiFphwcyWbvrlIRD3QIOcZVxbmXFy7UCxVO9mqMQPv6wee93Ng2Sh4M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771750179; c=relaxed/simple; bh=iAyfZHGom5QIZEtYKc+A9YZYnBeGnAnI+yMmjM4jWRM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NQxGTPbcH4CRUBrgRz2eJ96edvCLD6HsKxYqROOYa7jUVpZ9ZaO9OySPBGeiDcvvdbonSavMST8ThRvh6l872HJK0IzKtekjsPY7CDnuasLW++OBZYbJ8ZmEGrRJy6E1nxpb6VcML5ZslSoPZxDDvEkVz10YxXrN+4r5gwz7IAE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=gourry.net; spf=pass smtp.mailfrom=gourry.net; dkim=pass (2048-bit key) header.d=gourry.net header.i=@gourry.net header.b=tEpcv9fO; arc=none smtp.client-ip=209.85.160.179 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=gourry.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gourry.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gourry.net header.i=@gourry.net header.b="tEpcv9fO" Received: by mail-qt1-f179.google.com with SMTP id d75a77b69052e-5069df1d711so31419451cf.2 for ; Sun, 22 Feb 2026 00:49:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gourry.net; s=google; t=1771750177; x=1772354977; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=/yj+ZkijP1F57uDkd+kIZ1Nriaysy+Ep+EgiXsVeVTU=; b=tEpcv9fOflWF9zTz8xx9zc+QvmOmgDSKhksUu28JiiMoOhgJhFZPIIpGZrRbDupsxr qFuI77QDhrAavMLFK7H6tGZ3EK3yK0P/CKQcLRROPbkN1Z8w1zZynuLjtKAzo8s3L+c7 XkinxGHKbKAEd2+JhHynJRSRFR/6paFp3TPZ3nyt9dv0zZvU3m7R4Pg92ChHdD5UC/zh RSY4x5EqIiRbG+hicxDBbqV9y9NuEFkMUVeqryerStAEX8LTIyyBdqj2ACo7d6vfpdSD JlQY8lRgozO+lIAnMof8++Q9tkK80MAV80evhBw6NhQ/DGD2YyutQu2+K97LsVGtg6Vt N8tA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1771750177; x=1772354977; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=/yj+ZkijP1F57uDkd+kIZ1Nriaysy+Ep+EgiXsVeVTU=; b=jChdDYrcoYXOf9iCG3yiBRx/Gi9rhorCZbT7RV2yVpLb9pWhZm9Di4Fczrdy87rVnj UwOHblKEsz38/woJOhZGW32CclwBmhC4hBnrOjuVsHJtCCzONYgjp1t5eauLk4NXYTtL vm82ykDk3Zn3HutzRhNLfyRzL3lkLTQ+nlHxAr2Xm+GV0JVZLurQEM/tyEplIYlFPy3S U6m624+Qc/kDT5rK/KLEo1vSmlPwzvT5aP0jb3hmtte1p/RAkBNkcM69CYRH8/40w1YN lD2tnFBRykGnZU3UMyOklFR00kHWhpAX72q8fcdSr/YedLpFuh/bSRZZ5iXsljAhnItJ d2rg== X-Forwarded-Encrypted: i=1; AJvYcCU2KaWb8z5VnXznfTyHxYEgk99X24CYLPEO+vgpT+iphh/Gnmn4gPN575LZ0i8j7g/FgPUO9I9sMrchz8Lq1BGxGPM=@vger.kernel.org X-Gm-Message-State: AOJu0Yz45bJhRmVJ+toqYclwuwldBms/T9S1xEms4lMLdi+CtUbl3iiW 6oK3UqGZ3rJILbItcVUEHAZ08n0ZyPl6ODM0isUOdiyDv+6ymvj1YHrBJfkX6WGYEEc= X-Gm-Gg: AZuq6aI4KvaykiVozxz6fs1hptNng4M0ot1JxASCEdgasjNfKlFDZRXfggqSYsTVLvS +Xyb5QUDG+uPS7Y4PHa0LSKMNsW6u87Ay2maTJeaZ7rzhBO5YAohmXrl3v0bU0gCbPB++ZE5cxb JAeIQ3BIJHxuIivuT2wKIlTd+xBhRP+uK3KIwq49abKmktnPcPojtNy6hEaMVCQnoo8ci7yh/BX EnbfoyJnbV8paYrGSet/aeiB0rHQY2Boqd2md+OqXSO14V6hgKUgCOQib3Bgzc5/kHlQycwdr+v 7d+NBA4sPbQDDvTq9XmRrWEDN839jgZ/PgqQfAjul/kH0bi9wqyAQckD+QlG+1+7rSVyqzdhcfj nwVYt+YOruwzjNhZNSWtk8oXgfNtooDHMHDYGZPa3K07pNE+X5J2/mRNFNJ+MJ+y5wPb3NZRM+S htEVL4ygd3NGX6wHqZwgu9Kce6mqr+Gb0pLQoubuuetwGKQISJ9Xw81fAch4Wt8ZqGe+wJlTHHj wJDDvN5g9MEnNU= X-Received: by 2002:ac8:5f52:0:b0:4f1:b712:364a with SMTP id d75a77b69052e-5070bc84890mr75076581cf.56.1771750177109; Sun, 22 Feb 2026 00:49:37 -0800 (PST) Received: from gourry-fedora-PF4VCD3F.lan (pool-96-255-20-138.washdc.ftas.verizon.net. [96.255.20.138]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-5070d53f0fcsm38640631cf.9.2026.02.22.00.49.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 22 Feb 2026 00:49:36 -0800 (PST) From: Gregory Price To: lsf-pc@lists.linux-foundation.org Cc: linux-kernel@vger.kernel.org, linux-cxl@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, damon@lists.linux.dev, kernel-team@meta.com, gregkh@linuxfoundation.org, rafael@kernel.org, dakr@kernel.org, dave@stgolabs.net, jonathan.cameron@huawei.com, dave.jiang@intel.com, alison.schofield@intel.com, vishal.l.verma@intel.com, ira.weiny@intel.com, dan.j.williams@intel.com, longman@redhat.com, akpm@linux-foundation.org, david@kernel.org, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, vbabka@suse.cz, rppt@kernel.org, surenb@google.com, mhocko@suse.com, osalvador@suse.de, ziy@nvidia.com, matthew.brost@intel.com, joshua.hahnjy@gmail.com, rakie.kim@sk.com, byungchul@sk.com, gourry@gourry.net, ying.huang@linux.alibaba.com, apopple@nvidia.com, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, yury.norov@gmail.com, linux@rasmusvillemoes.dk, mhiramat@kernel.org, mathieu.desnoyers@efficios.com, tj@kernel.org, hannes@cmpxchg.org, mkoutny@suse.com, jackmanb@google.com, sj@kernel.org, baolin.wang@linux.alibaba.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev, muchun.song@linux.dev, xu.xin16@zte.com.cn, chengming.zhou@linux.dev, jannh@google.com, linmiaohe@huawei.com, nao.horiguchi@gmail.com, pfalcato@suse.de, rientjes@google.com, shakeel.butt@linux.dev, riel@surriel.com, harry.yoo@oracle.com, cl@gentwo.org, roman.gushchin@linux.dev, chrisl@kernel.org, kasong@tencent.com, shikemeng@huaweicloud.com, nphamcs@gmail.com, bhe@redhat.com, zhengqi.arch@bytedance.com, terry.bowman@amd.com Subject: [RFC PATCH v4 11/27] mm/huge_memory.c: add private node folio split notification callback Date: Sun, 22 Feb 2026 03:48:26 -0500 Message-ID: <20260222084842.1824063-12-gourry@gourry.net> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260222084842.1824063-1-gourry@gourry.net> References: <20260222084842.1824063-1-gourry@gourry.net> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Some private node services may need to update internal metadata when a THP folio is split. ZONE_DEVICE already has a split callback via pgmap->ops; private nodes can provide the same capability. Just like zone_device, some private node services may want to know about a folio being split. Add this optional callback to the ops struct and add a wrapper for zone_device and private node callback dispatch to be consolidated. Wire this into __folio_split() where the zone_device check was made. Signed-off-by: Gregory Price --- include/linux/node_private.h | 33 +++++++++++++++++++++++++++++++++ mm/huge_memory.c | 6 ++++-- 2 files changed, 37 insertions(+), 2 deletions(-) diff --git a/include/linux/node_private.h b/include/linux/node_private.h index 09ea7c4cb13c..f9dd2d25c8a5 100644 --- a/include/linux/node_private.h +++ b/include/linux/node_private.h @@ -3,6 +3,7 @@ #define _LINUX_NODE_PRIVATE_H #include +#include #include #include #include @@ -44,11 +45,19 @@ struct vm_fault; * Returns: true if handled (skip return to buddy) * false if no op (return to buddy) * + * @folio_split: Notification that a folio on this private node is being split. + * [folio-referenced callback] + * Called from the folio split path via folio_managed_split_cb(). + * @folio is the original folio; @new_folio is the newly created folio, + * or NULL when called for the final (original) folio after all sub-folios + * have been split off. + * * @flags: Operation exclusion flags (NP_OPS_* constants). * */ struct node_private_ops { bool (*free_folio)(struct folio *folio); + void (*folio_split)(struct folio *folio, struct folio *new_folio); unsigned long flags; }; @@ -150,6 +159,24 @@ static inline bool zone_private_flags(struct zone *z, unsigned long flag) return node_private_flags(zone_to_nid(z)) & flag; } +static inline void node_private_split_cb(struct folio *folio, + struct folio *new_folio) +{ + const struct node_private_ops *ops = folio_node_private_ops(folio); + + if (ops && ops->folio_split) + ops->folio_split(folio, new_folio); +} + +static inline void folio_managed_split_cb(struct folio *original_folio, + struct folio *new_folio) +{ + if (folio_is_zone_device(original_folio)) + zone_device_private_split_cb(original_folio, new_folio); + else if (folio_is_private_node(original_folio)) + node_private_split_cb(original_folio, new_folio); +} + #else /* !CONFIG_NUMA */ static inline bool folio_is_private_node(struct folio *folio) @@ -198,6 +225,12 @@ static inline bool zone_private_flags(struct zone *z, unsigned long flag) return false; } +static inline void folio_managed_split_cb(struct folio *original_folio, + struct folio *new_folio) +{ + if (folio_is_zone_device(original_folio)) + zone_device_private_split_cb(original_folio, new_folio); +} #endif /* CONFIG_NUMA */ #if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 40cf59301c21..2ecae494291a 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include #include @@ -3850,7 +3851,7 @@ static int __folio_freeze_and_split_unmapped(struct folio *folio, unsigned int n next = folio_next(new_folio); - zone_device_private_split_cb(folio, new_folio); + folio_managed_split_cb(folio, new_folio); folio_ref_unfreeze(new_folio, folio_cache_ref_count(new_folio) + 1); @@ -3889,7 +3890,8 @@ static int __folio_freeze_and_split_unmapped(struct folio *folio, unsigned int n folio_put_refs(new_folio, nr_pages); } - zone_device_private_split_cb(folio, NULL); + folio_managed_split_cb(folio, NULL); + /* * Unfreeze @folio only after all page cache entries, which * used to point to it, have been updated with new folios. -- 2.53.0