From nobody Thu Apr 9 04:47:12 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B743AC4332F for ; Wed, 2 Nov 2022 12:07:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230324AbiKBMHY (ORCPT ); Wed, 2 Nov 2022 08:07:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35248 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229512AbiKBMHX (ORCPT ); Wed, 2 Nov 2022 08:07:23 -0400 Received: from SHSQR01.spreadtrum.com (unknown [222.66.158.135]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3669D64F7 for ; Wed, 2 Nov 2022 05:07:21 -0700 (PDT) Received: from SHSend.spreadtrum.com (bjmbx01.spreadtrum.com [10.0.64.7]) by SHSQR01.spreadtrum.com with ESMTPS id 2A2C6eDg084573 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NO); Wed, 2 Nov 2022 20:06:40 +0800 (CST) (envelope-from zhaoyang.huang@unisoc.com) Received: from bj03382pcu.spreadtrum.com (10.0.74.65) by BJMBX01.spreadtrum.com (10.0.64.7) with Microsoft SMTP Server (TLS) id 15.0.1497.23; Wed, 2 Nov 2022 20:06:41 +0800 From: "zhaoyang.huang" To: Andrew Morton , Vlastimil Babka , Zhaoyang Huang , , , , Subject: [RFC PATCH] mm: introduce accounting of page_owner via backtrace Date: Wed, 2 Nov 2022 20:06:21 +0800 Message-ID: <1667390781-17515-1-git-send-email-zhaoyang.huang@unisoc.com> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 X-Originating-IP: [10.0.74.65] X-ClientProxiedBy: SHCAS01.spreadtrum.com (10.0.1.201) To BJMBX01.spreadtrum.com (10.0.64.7) X-MAIL: SHSQR01.spreadtrum.com 2A2C6eDg084573 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Zhaoyang Huang Page_owner could be accounted and sort via its backtrace, which could simplify the output. Signed-off-by: Zhaoyang Huang --- include/linux/page_owner.h | 7 +++ mm/page_owner.c | 113 +++++++++++++++++++++++++++++++++++++++++= ++++ 2 files changed, 120 insertions(+) diff --git a/include/linux/page_owner.h b/include/linux/page_owner.h index 119a0c9..c86a342 100644 --- a/include/linux/page_owner.h +++ b/include/linux/page_owner.h @@ -3,6 +3,13 @@ #define __LINUX_PAGE_OWNER_H =20 #include +#include + +struct hash_object { + int count; + depot_stack_handle_t trace_hash; + struct rb_node rb_node; +}; =20 #ifdef CONFIG_PAGE_OWNER extern struct static_key_false page_owner_inited; diff --git a/mm/page_owner.c b/mm/page_owner.c index e4c6f3f..3d014fd 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -42,6 +42,12 @@ struct page_owner { static depot_stack_handle_t early_handle; =20 static void init_early_allocated_pages(void); +static void store_user_hash(depot_stack_handle_t trace_hash, int count); +static DEFINE_SPINLOCK(stack_hash_lock); +static struct hash_object ho_pool[8192]; +static int ho_pool_free_count =3D ARRAY_SIZE(ho_pool); +struct rb_root user_hash_root =3D RB_ROOT; + =20 static int __init early_page_owner_param(char *buf) { @@ -152,6 +158,8 @@ void __reset_page_owner(struct page *page, unsigned sho= rt order) page_owner->free_handle =3D handle; page_owner->free_ts_nsec =3D free_ts_nsec; page_ext =3D page_ext_next(page_ext); + if (!i) + store_user_hash(page_owner->handle, -(1 << order)); } } =20 @@ -190,6 +198,7 @@ noinline void __set_page_owner(struct page *page, unsig= ned short order, return; =20 handle =3D save_stack(gfp_mask); + store_user_hash(handle, 1 << order); __set_page_owner_handle(page_ext, handle, order, gfp_mask); } =20 @@ -570,6 +579,105 @@ void __dump_page_owner(const struct page *page) return 0; } =20 +static void store_user_hash(depot_stack_handle_t trace_hash, int count) +{ + struct rb_node *rb_parent; + unsigned int trace_hash_parent; + struct rb_node **link =3D &user_hash_root.rb_node; + struct hash_object *hash_parent =3D NULL; + struct hash_object *hash_object =3D NULL; + unsigned long flags; + + spin_lock_irqsave(&stack_hash_lock, flags); + while (*link) { + rb_parent =3D *link; + hash_parent =3D rb_entry(rb_parent, struct hash_object, rb_node); + trace_hash_parent =3D hash_parent->trace_hash; + if (trace_hash < trace_hash_parent) + link =3D &hash_parent->rb_node.rb_left; + else if (trace_hash_parent < trace_hash) + link =3D &hash_parent->rb_node.rb_right; + else { + hash_object =3D rb_entry(*link, struct hash_object, rb_node); + hash_object->count +=3D count; + if (!RB_EMPTY_ROOT(&user_hash_root) + && !hash_object->count) { + rb_erase(&hash_object->rb_node, &user_hash_root); + } + spin_unlock_irqrestore(&stack_hash_lock, flags); + return; + } + } + /* + * hash_object is the 1st node represent this trace_hash + * insert it to user_hash_root + */ + hash_object =3D ho_pool_free_count ? &ho_pool[--ho_pool_free_count] : NUL= L; + if (!hash_object) { + spin_unlock_irqrestore(&stack_hash_lock, flags); + return; + } + hash_object->trace_hash =3D trace_hash; + /* add the node to rb tree*/ + rb_link_node(&hash_object->rb_node, rb_parent, link); + rb_insert_color(&hash_object->rb_node, &user_hash_root); + spin_unlock_irqrestore(&stack_hash_lock, flags); + return; +} +static ssize_t print_owner_stack(struct file *file, char __user *buf, size= _t count, loff_t *ppos) +{ + struct hash_object *object; + struct rb_node *rb; + unsigned long *entries; + unsigned int nr_entries; + char *kbuf; + int i, ret =3D 0; + unsigned long flags; + + count =3D min_t(size_t, count, PAGE_SIZE); + kbuf =3D kmalloc(count, GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + + rb =3D file->private_data ? (struct rb_node *)file->private_data : rb_fir= st(&user_hash_root); + if(!rb) + return 0; + spin_lock_irqsave(&stack_hash_lock, flags); + object =3D rb_entry(rb, struct hash_object, rb_node); + if (object) { + while (!object->trace_hash || object->count <=3D 0) { + rb =3D rb_next(rb); + object =3D rb ? rb_entry(rb, struct hash_object, rb_node) : NULL; + if (!object) { + spin_unlock_irqrestore(&stack_hash_lock, flags); + kfree(kbuf); + return 0; + } + } + nr_entries =3D stack_depot_fetch(object->trace_hash, &entries); + ret +=3D snprintf(kbuf + ret, count - ret, "count %d\n", object->count); + if (ret >=3D count) + goto err; + for (i =3D 0; i < nr_entries; i++) { + void *ptr =3D (void *)entries[i]; + ret +=3D snprintf(kbuf + ret, count - ret, " [<%p>] %pS\n", ptr, ptr= ); + if (ret >=3D count) + goto err; + } + } + file->private_data =3D (void *)rb_next(rb); + spin_unlock_irqrestore(&stack_hash_lock, flags); + if (copy_to_user(buf, kbuf, ret)) + ret =3D -EFAULT; + + kfree(kbuf); + return ret; +err: + spin_unlock_irqrestore(&stack_hash_lock, flags); + kfree(kbuf); + return -ENOMEM; +} + static void init_pages_in_zone(pg_data_t *pgdat, struct zone *zone) { unsigned long pfn =3D zone->zone_start_pfn; @@ -661,6 +769,9 @@ static void init_early_allocated_pages(void) static const struct file_operations proc_page_owner_operations =3D { .read =3D read_page_owner, }; +static const struct file_operations proc_page_owner_simple_operations =3D { + .read =3D print_owner_stack, +}; =20 static int __init pageowner_init(void) { @@ -671,6 +782,8 @@ static int __init pageowner_init(void) =20 debugfs_create_file("page_owner", 0400, NULL, NULL, &proc_page_owner_operations); + debugfs_create_file("page_owner_simple", 0400, NULL, NULL, + &proc_page_owner_simple_operations); =20 return 0; } --=20 1.9.1