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 <[email protected]> Signed-off-by: Hongzhen Luo <[email protected]> Signed-off-by: Hongbo Li <[email protected]> --- fs/erofs/data.c | 30 +++++++++++++++++++++++------- fs/erofs/inode.c | 4 ++++ fs/erofs/internal.h | 17 +++++++++++++++++ fs/erofs/ishare.c | 31 +++++++++++++++++++++++++++++++ 4 files changed, 75 insertions(+), 7 deletions(-) diff --git a/fs/erofs/data.c b/fs/erofs/data.c index 71e23d91123d..862df0c7ceb7 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 +381,42 @@ 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 = {}; + struct erofs_iomap_iter_ctx iter_ctx = { + .realinode = erofs_ishare_iget(inode), + }; + if (!iter_ctx.realinode) + return -EIO; trace_erofs_read_folio(folio, true); iomap_read_folio(&erofs_iomap_ops, &read_ctx, &iter_ctx); + erofs_ishare_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 = {}; + struct erofs_iomap_iter_ctx iter_ctx = { + .realinode = erofs_ishare_iget(inode), + }; + if (!iter_ctx.realinode) + return; trace_erofs_readahead(rac->mapping->host, readahead_index(rac), readahead_count(rac), true); iomap_readahead(&erofs_iomap_ops, &read_ctx, &iter_ctx); + erofs_ishare_iput(iter_ctx.realinode); } static sector_t erofs_bmap(struct address_space *mapping, sector_t block) @@ -423,7 +437,9 @@ 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 cb780c095d28..3be4614d1add 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 93ad34f2b488..37b536eebc3d 100644 --- a/fs/erofs/internal.h +++ b/fs/erofs/internal.h @@ -197,6 +197,19 @@ static inline bool erofs_is_fscache_mode(struct super_block *sb) !erofs_is_fileio_mode(EROFS_SB(sb)) && !sb->s_bdev; } +#if defined(CONFIG_EROFS_FS_INODE_SHARE) +static inline bool erofs_is_ishare_inode(struct inode *inode) +{ + /* we have assumed FS_ONDEMAND is excluded with FS_INODE_SHARE feature */ + return inode->i_sb->s_type == &erofs_anon_fs_type; +} +#else +static inline bool erofs_is_ishare_inode(struct inode *inode) +{ + return false; +} +#endif + enum { EROFS_ZIP_CACHE_DISABLED, EROFS_ZIP_CACHE_READAHEAD, @@ -563,11 +576,15 @@ int erofs_ishare_init(struct super_block *sb); void erofs_ishare_exit(struct super_block *sb); bool erofs_ishare_fill_inode(struct inode *inode); void erofs_ishare_free_inode(struct inode *inode); +struct inode *erofs_ishare_iget(struct inode *inode); +void erofs_ishare_iput(struct inode *realinode); #else static inline int erofs_ishare_init(struct super_block *sb) { return 0; } static inline void erofs_ishare_exit(struct super_block *sb) {} 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_ishare_iget(struct inode *inode) { return inode; } +static inline void erofs_ishare_iput(struct inode *realinode) {} #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 f386efb260da..da735d69f21f 100644 --- a/fs/erofs/ishare.c +++ b/fs/erofs/ishare.c @@ -239,3 +239,34 @@ const struct file_operations erofs_ishare_fops = { .get_unmapped_area = thp_get_unmapped_area, .splice_read = filemap_splice_read, }; + +/* + * erofs_ishare_iget - find the backing inode. + */ +struct inode *erofs_ishare_iget(struct inode *inode) +{ + struct erofs_inode *vi, *vi_dedup; + struct inode *realinode; + + if (!erofs_is_ishare_inode(inode)) + return igrab(inode); + + vi_dedup = EROFS_I(inode); + spin_lock(&vi_dedup->lock); + /* fall back to all backing inodes */ + DBG_BUGON(list_empty(&vi_dedup->backing_head)); + list_for_each_entry(vi, &vi_dedup->backing_head, backing_link) { + realinode = igrab(&vi->vfs_inode); + if (realinode) + break; + } + spin_unlock(&vi_dedup->lock); + + DBG_BUGON(!realinode); + return realinode; +} + +void erofs_ishare_iput(struct inode *realinode) +{ + iput(realinode); +} -- 2.22.0
