From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-132.freemail.mail.aliyun.com (out30-132.freemail.mail.aliyun.com [115.124.30.132]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 14C321FB1; Wed, 24 Dec 2025 08:15:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.132 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766564144; cv=none; b=oqgrE8ftBXwA8KeXcldKB9EiXiHIcN+R+W0RFJrZT3Ssqzxuv7Qx+zJgODm7FIDGbva2ZEvOR2b7jINPmq8hL6fHXDGwcZWDzhkLPS8FiLjgIVCzqUCTxoaKinhzc9680PpcJ2fcsEUmHGFsXTPljcybp6qxckQkdtlVCio6uK8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766564144; c=relaxed/simple; bh=SBy60DwRvJ0bD3Unmlcv8b9xSSB976Xj8wcUlep7TIA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=AF0/3PfIBk5nSVXT/2Y+jwdx9887KYwf+sc31E5cc3h+MfyJ/GfYXJyiXkkrLgzf7yw3Iu8yhcLT1Ugs6Do+kAWuY5ShbQcBZlJHhLBhykLMdNp67/s7FBj7t6xwCt+tKqR3bJflsrgM+OQPe+2i+tgvnKQR2ruZN8kv0cTpwmY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=fvlYlZPB; arc=none smtp.client-ip=115.124.30.132 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="fvlYlZPB" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1766564135; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=HvNtWBYHjlKadnKRSAAlto1QAZJUw+2Q2TRFjKQurLY=; b=fvlYlZPBOb4tSBJqwU89Q6fQrKvrG2m2xpJFkOIEyOwYLaonMgtd/JlvSgn4CDhDj2hX6tgVsT8Ua4d49BscYOWENp3lmmJyA/W9lf6hfsl4NGUqv+glmrau3fROXN6to4yqIS5Fcr2+1B6rwknY22zlAo2u/NtSUISsvPeCq4I= Received: from 30.221.133.159(mailfrom:hsiangkao@linux.alibaba.com fp:SMTPD_---0WvaNGZF_1766564134 cluster:ay36) by smtp.aliyun-inc.com; Wed, 24 Dec 2025 16:15:35 +0800 Message-ID: <7898bedf-0c02-432b-999a-01437265b51b@linux.alibaba.com> Date: Wed, 24 Dec 2025 16:15:34 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v11 08/10] erofs: support unencoded inodes for page cache share To: Hongbo Li Cc: linux-fsdevel@vger.kernel.org, linux-erofs@lists.ozlabs.org, linux-kernel@vger.kernel.org, Chao Yu , Christian Brauner , "Darrick J. Wong" , Amir Goldstein , Christoph Hellwig References: <20251224040932.496478-1-lihongbo22@huawei.com> <20251224040932.496478-9-lihongbo22@huawei.com> From: Gao Xiang In-Reply-To: <20251224040932.496478-9-lihongbo22@huawei.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2025/12/24 12:09, Hongbo Li wrote: > This patch adds inode page cache sharing functionality for unencoded > files. > > I conducted experiments in the container environment. Below is the > memory usage for reading all files in two different minor versions > of container images: > > +-------------------+------------------+-------------+---------------+ > | Image | Page Cache Share | Memory (MB) | Memory | > | | | | Reduction (%) | > +-------------------+------------------+-------------+---------------+ > | | No | 241 | - | > | redis +------------------+-------------+---------------+ > | 7.2.4 & 7.2.5 | Yes | 163 | 33% | > +-------------------+------------------+-------------+---------------+ > | | No | 872 | - | > | postgres +------------------+-------------+---------------+ > | 16.1 & 16.2 | Yes | 630 | 28% | > +-------------------+------------------+-------------+---------------+ > | | No | 2771 | - | > | tensorflow +------------------+-------------+---------------+ > | 2.11.0 & 2.11.1 | Yes | 2340 | 16% | > +-------------------+------------------+-------------+---------------+ > | | No | 926 | - | > | mysql +------------------+-------------+---------------+ > | 8.0.11 & 8.0.12 | Yes | 735 | 21% | > +-------------------+------------------+-------------+---------------+ > | | No | 390 | - | > | nginx +------------------+-------------+---------------+ > | 7.2.4 & 7.2.5 | Yes | 219 | 44% | > +-------------------+------------------+-------------+---------------+ > | tomcat | No | 924 | - | > | 10.1.25 & 10.1.26 +------------------+-------------+---------------+ > | | Yes | 474 | 49% | > +-------------------+------------------+-------------+---------------+ > > Additionally, the table below shows the runtime memory usage of the > container: > > +-------------------+------------------+-------------+---------------+ > | Image | Page Cache Share | Memory (MB) | Memory | > | | | | Reduction (%) | > +-------------------+------------------+-------------+---------------+ > | | No | 35 | - | > | redis +------------------+-------------+---------------+ > | 7.2.4 & 7.2.5 | Yes | 28 | 20% | > +-------------------+------------------+-------------+---------------+ > | | No | 149 | - | > | postgres +------------------+-------------+---------------+ > | 16.1 & 16.2 | Yes | 95 | 37% | > +-------------------+------------------+-------------+---------------+ > | | No | 1028 | - | > | tensorflow +------------------+-------------+---------------+ > | 2.11.0 & 2.11.1 | Yes | 930 | 10% | > +-------------------+------------------+-------------+---------------+ > | | No | 155 | - | > | mysql +------------------+-------------+---------------+ > | 8.0.11 & 8.0.12 | Yes | 132 | 15% | > +-------------------+------------------+-------------+---------------+ > | | No | 25 | - | > | nginx +------------------+-------------+---------------+ > | 7.2.4 & 7.2.5 | Yes | 20 | 20% | > +-------------------+------------------+-------------+---------------+ > | tomcat | No | 186 | - | > | 10.1.25 & 10.1.26 +------------------+-------------+---------------+ > | | Yes | 98 | 48% | > +-------------------+------------------+-------------+---------------+ > > Co-developed-by: Hongzhen Luo > Signed-off-by: Hongzhen Luo > Signed-off-by: Hongbo Li > --- > fs/erofs/data.c | 32 +++++++++++++++++++++++++------- > fs/erofs/inode.c | 4 ++++ > fs/erofs/internal.h | 2 ++ > fs/erofs/ishare.c | 31 +++++++++++++++++++++++++++++++ > 4 files changed, 62 insertions(+), 7 deletions(-) > > diff --git a/fs/erofs/data.c b/fs/erofs/data.c > index 71e23d91123d..cbe7ac194b09 100644 > --- a/fs/erofs/data.c > +++ b/fs/erofs/data.c > @@ -269,6 +269,7 @@ void erofs_onlinefolio_end(struct folio *folio, int err, bool dirty) > struct erofs_iomap_iter_ctx { > struct page *page; > void *base; > + struct inode *realinode; > }; > > static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length, > @@ -276,14 +277,15 @@ static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length, > { > struct iomap_iter *iter = container_of(iomap, struct iomap_iter, iomap); > struct erofs_iomap_iter_ctx *ctx = iter->private; > - struct super_block *sb = inode->i_sb; > + struct inode *realinode = ctx ? ctx->realinode : inode; > + struct super_block *sb = realinode->i_sb; > struct erofs_map_blocks map; > struct erofs_map_dev mdev; > int ret; > > map.m_la = offset; > map.m_llen = length; > - ret = erofs_map_blocks(inode, &map); > + ret = erofs_map_blocks(realinode, &map); > if (ret < 0) > return ret; > > @@ -296,7 +298,7 @@ static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length, > return 0; > } > > - if (!(map.m_flags & EROFS_MAP_META) || !erofs_inode_in_metabox(inode)) { > + if (!(map.m_flags & EROFS_MAP_META) || !erofs_inode_in_metabox(realinode)) { > mdev = (struct erofs_map_dev) { > .m_deviceid = map.m_deviceid, > .m_pa = map.m_pa, > @@ -322,7 +324,7 @@ static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length, > void *ptr; > > ptr = erofs_read_metabuf(&buf, sb, map.m_pa, > - erofs_inode_in_metabox(inode)); > + erofs_inode_in_metabox(realinode)); > if (IS_ERR(ptr)) > return PTR_ERR(ptr); > iomap->inline_data = ptr; > @@ -379,30 +381,44 @@ int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, > */ > static int erofs_read_folio(struct file *file, struct folio *folio) > { > + struct inode *inode = folio_inode(folio); > struct iomap_read_folio_ctx read_ctx = { > .ops = &iomap_bio_read_ops, > .cur_folio = folio, > }; > - struct erofs_iomap_iter_ctx iter_ctx = {}; > + bool need_iput = false; `bool need_iput` is enough, see below. > + struct erofs_iomap_iter_ctx iter_ctx = {> + .realinode = erofs_real_inode(inode, &need_iput), > + }; > > + DBG_BUGON(!iter_ctx.realinode); just remove this line, since erofs_real_inode() already has this check. > trace_erofs_read_folio(folio, true); > > iomap_read_folio(&erofs_iomap_ops, &read_ctx, &iter_ctx); > + if (need_iput) > + iput(iter_ctx.realinode); > return 0; > } > > static void erofs_readahead(struct readahead_control *rac) > { > + struct inode *inode = rac->mapping->host; > struct iomap_read_folio_ctx read_ctx = { > .ops = &iomap_bio_read_ops, > .rac = rac, > }; > - struct erofs_iomap_iter_ctx iter_ctx = {}; > + bool need_iput = false; `bool need_iput` is enough, see below. > + struct erofs_iomap_iter_ctx iter_ctx = { > + .realinode = erofs_real_inode(inode, &need_iput), > + }; > > + DBG_BUGON(!iter_ctx.realinode); just remove this line, since erofs_real_inode() already has this check. > trace_erofs_readahead(rac->mapping->host, readahead_index(rac), > readahead_count(rac), true); > > iomap_readahead(&erofs_iomap_ops, &read_ctx, &iter_ctx); > + if (need_iput) > + iput(iter_ctx.realinode); > } > > static sector_t erofs_bmap(struct address_space *mapping, sector_t block) > @@ -423,7 +439,9 @@ static ssize_t erofs_file_read_iter(struct kiocb *iocb, struct iov_iter *to) > return dax_iomap_rw(iocb, to, &erofs_iomap_ops); > #endif > if ((iocb->ki_flags & IOCB_DIRECT) && inode->i_sb->s_bdev) { > - struct erofs_iomap_iter_ctx iter_ctx = {}; > + struct erofs_iomap_iter_ctx iter_ctx = { > + .realinode = inode, > + }; > > return iomap_dio_rw(iocb, to, &erofs_iomap_ops, > NULL, 0, &iter_ctx, 0); > diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c > index bce98c845a18..8116738fe432 100644 > --- a/fs/erofs/inode.c > +++ b/fs/erofs/inode.c > @@ -215,6 +215,10 @@ static int erofs_fill_inode(struct inode *inode) > case S_IFREG: > inode->i_op = &erofs_generic_iops; > inode->i_fop = &erofs_file_fops; > +#ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE > + if (erofs_ishare_fill_inode(inode)) > + inode->i_fop = &erofs_ishare_fops; > +#endif > break; > case S_IFDIR: > inode->i_op = &erofs_dir_iops; > diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h > index a2b2434ee3c8..6930cce8f1fb 100644 > --- a/fs/erofs/internal.h > +++ b/fs/erofs/internal.h > @@ -565,11 +565,13 @@ int __init erofs_init_ishare(void); > void erofs_exit_ishare(void); > bool erofs_ishare_fill_inode(struct inode *inode); > void erofs_ishare_free_inode(struct inode *inode); > +struct inode *erofs_real_inode(struct inode *inode, bool *need_iput); > #else > static inline int erofs_init_ishare(void) { return 0; } > static inline void erofs_exit_ishare(void) {} > static inline bool erofs_ishare_fill_inode(struct inode *inode) { return false; } > static inline void erofs_ishare_free_inode(struct inode *inode) {} > +static inline struct inode *erofs_real_inode(struct inode *inode, bool *need_iput) { return inode; } static inline struct inode *erofs_real_inode(struct inode *inode, bool *need_iput) { *need_iput = false; return inode; } > #endif // CONFIG_EROFS_FS_PAGE_CACHE_SHARE > > long erofs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg); > diff --git a/fs/erofs/ishare.c b/fs/erofs/ishare.c > index 09ea456f2eab..634b7ea63738 100644 > --- a/fs/erofs/ishare.c > +++ b/fs/erofs/ishare.c > @@ -11,6 +11,12 @@ > > static struct vfsmount *erofs_ishare_mnt; > > +static inline bool erofs_is_ishare_inode(struct inode *inode) > +{ > + /* assumed FS_ONDEMAND is excluded with FS_PAGE_CACHE_SHARE feature */ > + return inode->i_sb->s_type == &erofs_anon_fs_type; > +} > + > static int erofs_ishare_iget5_eq(struct inode *inode, void *data) > { > struct erofs_inode_fingerprint *fp1 = &EROFS_I(inode)->fingerprint; > @@ -157,6 +163,31 @@ const struct file_operations erofs_ishare_fops = { > .splice_read = filemap_splice_read, > }; > > +struct inode *erofs_real_inode(struct inode *inode, bool *need_iput) > +{ > + struct erofs_inode *vi, *vi_dedup; > + struct inode *realinode; *need_iput = false; here Thanks, Gao Xiang > + > + if (!erofs_is_ishare_inode(inode)) > + return inode; > + > + vi_dedup = EROFS_I(inode); > + spin_lock(&vi_dedup->ishare_lock); > + /* fetch any one as real inode */ > + DBG_BUGON(list_empty(&vi_dedup->ishare_list)); > + list_for_each_entry(vi, &vi_dedup->ishare_list, ishare_list) { > + realinode = igrab(&vi->vfs_inode); > + if (realinode) { > + *need_iput = true; > + break; > + } > + } > + spin_unlock(&vi_dedup->ishare_lock); > + > + DBG_BUGON(!realinode); > + return realinode; > +} > + > int __init erofs_init_ishare(void) > { > erofs_ishare_mnt = kern_mount(&erofs_anon_fs_type);