From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m16.mail.163.com (m16.mail.163.com [117.135.210.3]) by smtp.subspace.kernel.org (Postfix) with ESMTP id D24F841C69; Mon, 24 Mar 2025 03:27:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=117.135.210.3 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742786844; cv=none; b=bythI3eBKeyVCyz62B4G9tBKTES7fkxjWh3vyW/SePkRU3LF4ocVhOqGRbhCkByAInt9aZhT4090eK1Sv9SBa9YFbm0Gm5GeK9UL0lkINDcyisCEU/u+xM9aNpmErCNeilIMHEXVeufbgQR1M0IiWAnr9ovhDnScZ7gi6D6COE0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742786844; c=relaxed/simple; bh=Xf2ozL92Gzlryg9xYd9n8bZc3aBJ+vAiIawfSXBJIis=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=MX53ryNZRgTjEXRSW+9k008hUFB4XDo10Kycd/ww7CPYQ7yKa0qB7kXf4ZmAl5QbjQK3P1u03obyoDWUQCfSyaq1nVhGeWzDP8JzsJ7SA6sTQ39XdkkrUVYX6VLQvgRCoJgrhouL2lkT6mh80LzIqof9wl0pHP48jdJce0hhSJI= 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=CcNhVdVG; arc=none smtp.client-ip=117.135.210.3 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="CcNhVdVG" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=Message-ID:Date:MIME-Version:Subject:From: Content-Type; bh=HkbejiPMTMwvJkup0zgJvuVm3HcrQGNtexmCZvXZV6Q=; b=CcNhVdVGCGSAQ1vmsePlw+MbAWWGDCHNksI+gvYxVcQd7oEDhfo8114/WCPUts NK1PuigMIeeYzcnedKib2qve8ZEpMMeTxRUnk09b1WmzoP682Xn4AO9qckB7m3+o 6gjt7zcdP6QaQRqJMURxoRweGf7H934H63Pls5PyQ495U= Received: from [192.168.22.248] (unknown [223.70.253.31]) by gzsmtp5 (Coremail) with SMTP id QCgvCgA3eaaU0OBnwVitSA--.46911S2; Mon, 24 Mar 2025 11:25:11 +0800 (CST) Message-ID: Date: Mon, 24 Mar 2025 11:25:08 +0800 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4] fs/proc/page: Refactoring to reduce code duplication. 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, 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 References: <20250318063226.223284-1-liuyerd@163.com> Content-Language: en-US From: Liu Ye In-Reply-To: <20250318063226.223284-1-liuyerd@163.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-CM-TRANSID:QCgvCgA3eaaU0OBnwVitSA--.46911S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxKr45tr4kKFyxZFW7Jw1DKFg_yoWxur4fpF s8GF4jyw4xX34Ykr17Jws8Za45u3s5Za1Yy3y7G34fXa47twnakFySy3Z0vFy8GryUZF48 WFWq9r1akFWUtFJanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07jwa93UUUUU= X-CM-SenderInfo: 5olx5vlug6il2tof0z/xtbBMQ8aTGfgx7fuFQAAsk Friendly ping. 在 2025/3/18 14:32, Liu Ye 写道: > 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 > > --- > 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) > > +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 > } > > -/* /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 = get_max_dump_pfn(); > u64 __user *out = (u64 __user *)buf; > + struct page *page; > unsigned long src = *ppos; > unsigned long pfn; > ssize_t ret = 0; > + u64 info; > > pfn = src / KPMSIZE; > if (src & KPMMASK || count & KPMMASK) > @@ -59,24 +63,34 @@ static ssize_t kpagecount_read(struct file *file, char __user *buf, > count = min_t(unsigned long, count, (max_dump_pfn * KPMSIZE) - src); > > while (count > 0) { > - struct page *page; > - u64 mapcount = 0; > - > /* > * TODO: ZONE_DEVICE support requires to identify > * memmaps that were actually initialized. > */ > page = pfn_to_online_page(pfn); > - if (page) { > - struct folio *folio = page_folio(page); > > - if (IS_ENABLED(CONFIG_PAGE_MAPCOUNT)) > - mapcount = folio_precise_page_mapcount(folio, page); > - else > - mapcount = folio_average_page_mapcount(folio); > - } > - > - if (put_user(mapcount, out)) { > + if (page) { > + switch (op) { > + case KPAGE_FLAGS: > + info = stable_page_flags(page); > + break; > + case KPAGE_COUNT: > + if (IS_ENABLED(CONFIG_PAGE_MAPCOUNT)) > + info = folio_precise_page_mapcount(page_folio(page), page); > + else > + info = folio_average_page_mapcount(page_folio(page)); > + break; > + case KPAGE_CGROUP: > + info = page_cgroup_ino(page); > + break; > + default: > + info = 0; > + break; > + } > + } else > + info = 0; > + > + if (put_user(info, out)) { > ret = -EFAULT; > break; > } > @@ -94,17 +108,23 @@ static ssize_t kpagecount_read(struct file *file, char __user *buf, > return ret; > } > > +/* /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 = { > .proc_flags = PROC_ENTRY_PERMANENT, > .proc_lseek = mem_lseek, > .proc_read = kpagecount_read, > }; > > -/* /proc/kpageflags - an array exposing page flags > - * > - * Each entry is a u64 representing the corresponding > - * physical page flags. > - */ > > 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 > > return u; > -}; > +} > > +/* /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 = get_max_dump_pfn(); > - u64 __user *out = (u64 __user *)buf; > - unsigned long src = *ppos; > - unsigned long pfn; > - ssize_t ret = 0; > - > - pfn = src / KPMSIZE; > - if (src & KPMMASK || count & KPMMASK) > - return -EINVAL; > - if (src >= max_dump_pfn * KPMSIZE) > - return 0; > - count = 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 = pfn_to_online_page(pfn); > - > - if (put_user(stable_page_flags(page), out)) { > - ret = -EFAULT; > - break; > - } > - > - pfn++; > - out++; > - count -= KPMSIZE; > - > - cond_resched(); > - } > - > - *ppos += (char __user *)out - buf; > - if (!ret) > - ret = (char __user *)out - buf; > - return ret; > + return kpage_read(file, buf, count, ppos, KPAGE_FLAGS); > } > > static const struct proc_ops kpageflags_proc_ops = { > @@ -276,53 +266,10 @@ static const struct proc_ops kpageflags_proc_ops = { > > #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 = get_max_dump_pfn(); > - u64 __user *out = (u64 __user *)buf; > - struct page *ppage; > - unsigned long src = *ppos; > - unsigned long pfn; > - ssize_t ret = 0; > - u64 ino; > - > - pfn = src / KPMSIZE; > - if (src & KPMMASK || count & KPMMASK) > - return -EINVAL; > - if (src >= max_dump_pfn * KPMSIZE) > - return 0; > - count = 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 = pfn_to_online_page(pfn); > - > - if (ppage) > - ino = page_cgroup_ino(ppage); > - else > - ino = 0; > - > - if (put_user(ino, out)) { > - ret = -EFAULT; > - break; > - } > - > - pfn++; > - out++; > - count -= KPMSIZE; > - > - cond_resched(); > - } > - > - *ppos += (char __user *)out - buf; > - if (!ret) > - ret = (char __user *)out - buf; > - return ret; > + return kpage_read(file, buf, count, ppos, KPAGE_CGROUP); > } > - > static const struct proc_ops kpagecgroup_proc_ops = { > .proc_flags = PROC_ENTRY_PERMANENT, > .proc_lseek = 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_cgroup *objcg, > { > } > > +static inline ino_t page_cgroup_ino(struct page *page) > +{ > + return 0; > +} > #endif /* CONFIG_MEMCG */ > > #if defined(CONFIG_MEMCG) && defined(CONFIG_ZSWAP)