From nobody Wed Dec 17 12:08:31 2025 Received: from m16.mail.163.com (m16.mail.163.com [117.135.210.4]) by smtp.subspace.kernel.org (Postfix) with ESMTP id E85EC4C6D; Tue, 18 Mar 2025 06:34:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=117.135.210.4 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742279656; cv=none; b=K6ek521MdNGSQM9IFttjiLFzYrKQPzlLU3gaVh9IBqEF2Q8zhqxEA0VM2qzBP8yC8UVxyrU+9GHnB0r0/O6BzaKMFAc+Fj6KDpHdwgXQbkwMu+77x/Z0humfHxhkRj3cPPk5uudrIooi0J+U8akyxF6YGLR8Q+N3R37jqh7oHrQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742279656; c=relaxed/simple; bh=R8IA/h5kuNMYoLSiaR1PFdQprQUncRuQof6zLLOa+Gw=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=O7nHlqaacuysipxm4H9hajiC4UjkTr9fN5zEVIuehChKSMFuxEs36ONmkUbW5cYLVxH8b69JGiNdkig5LQtzP+ghdA8kdA3jZtazMTEaDqHQnEC+W/vk0Oy02teIyN7Fz4QbCSidU2qkg14WTBBXIq+uV2lE9xyOJm6kMIpXyDw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=C2aHdx9E; arc=none smtp.client-ip=117.135.210.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="C2aHdx9E" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=/lMSm DJnLQOCrq8yGaCgmI/hezWy6ytM+F+ncidM3WY=; b=C2aHdx9EIQtVaa3mFsBHS /F2jAQxF2koD63mAcmLhPD5hzL+rn2ZObrWyrYJFUvTtnK5merK6LWCOD+feLOm1 T1s0wBWMeIqVv55HQFpEf0Yn3YV289ZWSG0H+fzUXXG3hxW9cLFPYKHFGIeVzcha EYl/FqhHZAU7sq8I2KqwQY= Received: from localhost.localdomain (unknown []) by gzga-smtp-mtada-g1-2 (Coremail) with SMTP id _____wDnj1R_E9lnWny0AA--.27191S2; Tue, 18 Mar 2025 14:32:32 +0800 (CST) From: Liu Ye To: hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev, shakeel.butt@linux.dev, muchun.song@linux.dev Cc: akpm@linux-foundation.org, willy@infradead.org, david@redhat.com, svetly.todorov@memverge.com, vbabka@suse.cz, liuyerd@163.com, ran.xiaokai@zte.com.cn, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, Liu Ye Subject: [PATCH v4] fs/proc/page: Refactoring to reduce code duplication. Date: Tue, 18 Mar 2025 14:32:26 +0800 Message-Id: <20250318063226.223284-1-liuyerd@163.com> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: _____wDnj1R_E9lnWny0AA--.27191S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxKr48XF4xZr1kuw4xZw4kXrb_yoWxAry8pF s8Gr4jyw48W34Ykr1xJ395Zas8G3s3Aa1Yy3y7G34Sva47JFnaka4SyFn0vFyxGryUZF1U ua909ry3CFWjyaDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07jnjjgUUUUU= X-CM-SenderInfo: 5olx5vlug6il2tof0z/1tbiKBAUTGfZDod+JgAAsP Content-Type: text/plain; charset="utf-8" From: Liu Ye The function kpageflags_read and kpagecgroup_read is quite similar to kpagecount_read. Consider refactoring common code into a helper function to reduce code duplication. Signed-off-by: Liu Ye Acked-by: David Hildenbrand --- V4 : Update code remake patch. V3 : Add a stub for page_cgroup_ino and remove the #ifdef CONFIG_MEMCG. V2 : Use an enumeration to indicate the operation to be performed to avoid passing functions. --- --- fs/proc/page.c | 161 +++++++++++++------------------------ include/linux/memcontrol.h | 4 + 2 files changed, 58 insertions(+), 107 deletions(-) diff --git a/fs/proc/page.c b/fs/proc/page.c index 23fc771100ae..999af26c7298 100644 --- a/fs/proc/page.c +++ b/fs/proc/page.c @@ -22,6 +22,12 @@ #define KPMMASK (KPMSIZE - 1) #define KPMBITS (KPMSIZE * BITS_PER_BYTE) =20 +enum kpage_operation { + KPAGE_FLAGS, + KPAGE_COUNT, + KPAGE_CGROUP, +}; + static inline unsigned long get_max_dump_pfn(void) { #ifdef CONFIG_SPARSEMEM @@ -37,19 +43,17 @@ static inline unsigned long get_max_dump_pfn(void) #endif } =20 -/* /proc/kpagecount - an array exposing page mapcounts - * - * Each entry is a u64 representing the corresponding - * physical page mapcount. - */ -static ssize_t kpagecount_read(struct file *file, char __user *buf, - size_t count, loff_t *ppos) +static ssize_t kpage_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos, + enum kpage_operation op) { const unsigned long max_dump_pfn =3D get_max_dump_pfn(); u64 __user *out =3D (u64 __user *)buf; + struct page *page; unsigned long src =3D *ppos; unsigned long pfn; ssize_t ret =3D 0; + u64 info; =20 pfn =3D src / KPMSIZE; if (src & KPMMASK || count & KPMMASK) @@ -59,24 +63,34 @@ static ssize_t kpagecount_read(struct file *file, char = __user *buf, count =3D min_t(unsigned long, count, (max_dump_pfn * KPMSIZE) - src); =20 while (count > 0) { - struct page *page; - u64 mapcount =3D 0; - /* * TODO: ZONE_DEVICE support requires to identify * memmaps that were actually initialized. */ page =3D pfn_to_online_page(pfn); - if (page) { - struct folio *folio =3D page_folio(page); =20 - if (IS_ENABLED(CONFIG_PAGE_MAPCOUNT)) - mapcount =3D folio_precise_page_mapcount(folio, page); - else - mapcount =3D folio_average_page_mapcount(folio); - } - - if (put_user(mapcount, out)) { + if (page) { + switch (op) { + case KPAGE_FLAGS: + info =3D stable_page_flags(page); + break; + case KPAGE_COUNT: + if (IS_ENABLED(CONFIG_PAGE_MAPCOUNT)) + info =3D folio_precise_page_mapcount(page_folio(page), page); + else + info =3D folio_average_page_mapcount(page_folio(page)); + break; + case KPAGE_CGROUP: + info =3D page_cgroup_ino(page); + break; + default: + info =3D 0; + break; + } + } else + info =3D 0; + + if (put_user(info, out)) { ret =3D -EFAULT; break; } @@ -94,17 +108,23 @@ static ssize_t kpagecount_read(struct file *file, char= __user *buf, return ret; } =20 +/* /proc/kpagecount - an array exposing page mapcounts + * + * Each entry is a u64 representing the corresponding + * physical page mapcount. + */ +static ssize_t kpagecount_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + return kpage_read(file, buf, count, ppos, KPAGE_COUNT); +} + static const struct proc_ops kpagecount_proc_ops =3D { .proc_flags =3D PROC_ENTRY_PERMANENT, .proc_lseek =3D mem_lseek, .proc_read =3D kpagecount_read, }; =20 -/* /proc/kpageflags - an array exposing page flags - * - * Each entry is a u64 representing the corresponding - * physical page flags. - */ =20 static inline u64 kpf_copy_bit(u64 kflags, int ubit, int kbit) { @@ -225,47 +245,17 @@ u64 stable_page_flags(const struct page *page) #endif =20 return u; -}; +} =20 +/* /proc/kpageflags - an array exposing page flags + * + * Each entry is a u64 representing the corresponding + * physical page flags. + */ static ssize_t kpageflags_read(struct file *file, char __user *buf, - size_t count, loff_t *ppos) + size_t count, loff_t *ppos) { - const unsigned long max_dump_pfn =3D get_max_dump_pfn(); - u64 __user *out =3D (u64 __user *)buf; - unsigned long src =3D *ppos; - unsigned long pfn; - ssize_t ret =3D 0; - - pfn =3D src / KPMSIZE; - if (src & KPMMASK || count & KPMMASK) - return -EINVAL; - if (src >=3D max_dump_pfn * KPMSIZE) - return 0; - count =3D min_t(unsigned long, count, (max_dump_pfn * KPMSIZE) - src); - - while (count > 0) { - /* - * TODO: ZONE_DEVICE support requires to identify - * memmaps that were actually initialized. - */ - struct page *page =3D pfn_to_online_page(pfn); - - if (put_user(stable_page_flags(page), out)) { - ret =3D -EFAULT; - break; - } - - pfn++; - out++; - count -=3D KPMSIZE; - - cond_resched(); - } - - *ppos +=3D (char __user *)out - buf; - if (!ret) - ret =3D (char __user *)out - buf; - return ret; + return kpage_read(file, buf, count, ppos, KPAGE_FLAGS); } =20 static const struct proc_ops kpageflags_proc_ops =3D { @@ -276,53 +266,10 @@ static const struct proc_ops kpageflags_proc_ops =3D { =20 #ifdef CONFIG_MEMCG static ssize_t kpagecgroup_read(struct file *file, char __user *buf, - size_t count, loff_t *ppos) + size_t count, loff_t *ppos) { - const unsigned long max_dump_pfn =3D get_max_dump_pfn(); - u64 __user *out =3D (u64 __user *)buf; - struct page *ppage; - unsigned long src =3D *ppos; - unsigned long pfn; - ssize_t ret =3D 0; - u64 ino; - - pfn =3D src / KPMSIZE; - if (src & KPMMASK || count & KPMMASK) - return -EINVAL; - if (src >=3D max_dump_pfn * KPMSIZE) - return 0; - count =3D min_t(unsigned long, count, (max_dump_pfn * KPMSIZE) - src); - - while (count > 0) { - /* - * TODO: ZONE_DEVICE support requires to identify - * memmaps that were actually initialized. - */ - ppage =3D pfn_to_online_page(pfn); - - if (ppage) - ino =3D page_cgroup_ino(ppage); - else - ino =3D 0; - - if (put_user(ino, out)) { - ret =3D -EFAULT; - break; - } - - pfn++; - out++; - count -=3D KPMSIZE; - - cond_resched(); - } - - *ppos +=3D (char __user *)out - buf; - if (!ret) - ret =3D (char __user *)out - buf; - return ret; + return kpage_read(file, buf, count, ppos, KPAGE_CGROUP); } - static const struct proc_ops kpagecgroup_proc_ops =3D { .proc_flags =3D PROC_ENTRY_PERMANENT, .proc_lseek =3D mem_lseek, diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 53364526d877..5264d148bdd9 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -1793,6 +1793,10 @@ static inline void count_objcg_events(struct obj_cgr= oup *objcg, { } =20 +static inline ino_t page_cgroup_ino(struct page *page) +{ + return 0; +} #endif /* CONFIG_MEMCG */ =20 #if defined(CONFIG_MEMCG) && defined(CONFIG_ZSWAP) --=20 2.25.1