Commit 34096ba9 authored by Hongbo Li's avatar Hongbo Li Committed by Gao Xiang
Browse files

erofs: support unencoded inodes for page cache share 



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: default avatarHongzhen Luo <hongzhen@linux.alibaba.com>
Signed-off-by: default avatarHongzhen Luo <hongzhen@linux.alibaba.com>
Signed-off-by: default avatarHongbo Li <lihongbo22@huawei.com>
Reviewed-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
parent 69368d2d

fs/erofs/data.c

+23 −9
Original line number Diff line number Diff line
@@ -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;
@@ -383,10 +385,15 @@ static int erofs_read_folio(struct file *file, struct folio *folio) 
		.ops		= &iomap_bio_read_ops,

		.cur_folio	= folio,

	};

	struct erofs_iomap_iter_ctx iter_ctx = {};

	bool need_iput;

	struct erofs_iomap_iter_ctx iter_ctx = {

		.realinode = erofs_real_inode(folio_inode(folio), &need_iput),

	};



	trace_erofs_read_folio(folio_inode(folio), folio, true);

	trace_erofs_read_folio(iter_ctx.realinode, folio, true);

	iomap_read_folio(&erofs_iomap_ops, &read_ctx, &iter_ctx);

	if (need_iput)

		iput(iter_ctx.realinode);

	return 0;

}
@@ -396,11 +403,16 @@ static void erofs_readahead(struct readahead_control *rac) 
		.ops		= &iomap_bio_read_ops,

		.rac		= rac,

	};

	struct erofs_iomap_iter_ctx iter_ctx = {};

	bool need_iput;

	struct erofs_iomap_iter_ctx iter_ctx = {

		.realinode = erofs_real_inode(rac->mapping->host, &need_iput),

	};



	trace_erofs_readahead(rac->mapping->host, readahead_index(rac),

	trace_erofs_readahead(iter_ctx.realinode, 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)
@@ -421,7 +433,9 @@ 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);

fs/erofs/fileio.c

+16 −9
Original line number Diff line number Diff line
@@ -88,9 +88,9 @@ void erofs_fileio_submit_bio(struct bio *bio) 
						   bio));

}



static int erofs_fileio_scan_folio(struct erofs_fileio *io, struct folio *folio)

static int erofs_fileio_scan_folio(struct erofs_fileio *io,

				   struct inode *inode, struct folio *folio)

{

	struct inode *inode = folio_inode(folio);

	struct erofs_map_blocks *map = &io->map;

	unsigned int cur = 0, end = folio_size(folio), len, attached = 0;

	loff_t pos = folio_pos(folio), ofs;
@@ -158,31 +158,38 @@ static int erofs_fileio_scan_folio(struct erofs_fileio *io, struct folio *folio) 


static int erofs_fileio_read_folio(struct file *file, struct folio *folio)

{

	bool need_iput;

	struct inode *realinode = erofs_real_inode(folio_inode(folio), &need_iput);

	struct erofs_fileio io = {};

	int err;



	trace_erofs_read_folio(folio_inode(folio), folio, true);

	err = erofs_fileio_scan_folio(&io, folio);

	trace_erofs_read_folio(realinode, folio, true);

	err = erofs_fileio_scan_folio(&io, realinode, folio);

	erofs_fileio_rq_submit(io.rq);

	if (need_iput)

		iput(realinode);

	return err;

}



static void erofs_fileio_readahead(struct readahead_control *rac)

{

	struct inode *inode = rac->mapping->host;

	bool need_iput;

	struct inode *realinode = erofs_real_inode(rac->mapping->host, &need_iput);

	struct erofs_fileio io = {};

	struct folio *folio;

	int err;



	trace_erofs_readahead(inode, readahead_index(rac),

	trace_erofs_readahead(realinode, readahead_index(rac),

			      readahead_count(rac), true);

	while ((folio = readahead_folio(rac))) {

		err = erofs_fileio_scan_folio(&io, folio);

		err = erofs_fileio_scan_folio(&io, realinode, folio);

		if (err && err != -EINTR)

			erofs_err(inode->i_sb, "readahead error at folio %lu @ nid %llu",

				  folio->index, EROFS_I(inode)->nid);

			erofs_err(realinode->i_sb, "readahead error at folio %lu @ nid %llu",

				  folio->index, EROFS_I(realinode)->nid);

	}

	erofs_fileio_rq_submit(io.rq);

	if (need_iput)

		iput(realinode);

}



const struct address_space_operations erofs_fileio_aops = {

fs/erofs/inode.c

+2 −1
Original line number Diff line number Diff line
@@ -213,7 +213,8 @@ static int erofs_fill_inode(struct inode *inode) 
	switch (inode->i_mode & S_IFMT) {

	case S_IFREG:

		inode->i_op = &erofs_generic_iops;

		inode->i_fop = &erofs_file_fops;

		inode->i_fop = erofs_ishare_fill_inode(inode) ?

			       &erofs_ishare_fops : &erofs_file_fops;

		break;

	case S_IFDIR:

		inode->i_op = &erofs_dir_iops;

fs/erofs/internal.h

+6 −0
Original line number Diff line number Diff line
@@ -584,11 +584,17 @@ 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)

{

	*need_iput = false;

	return inode;

}

#endif



long erofs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);

fs/erofs/ishare.c

+34 −0
Original line number Diff line number Diff line
@@ -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;
@@ -38,6 +44,8 @@ bool erofs_ishare_fill_inode(struct inode *inode) 
	struct inode *sharedinode;

	unsigned long hash;



	if (erofs_inode_is_data_compressed(vi->datalayout))

		return false;

	if (erofs_xattr_fill_inode_fingerprint(&fp, inode, sbi->domain_id))

		return false;

	hash = xxh32(fp.opaque, fp.size, 0);
@@ -155,6 +163,32 @@ 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_share;

	struct inode *realinode;



	*need_iput = false;

	if (!erofs_is_ishare_inode(inode))

		return inode;



	vi_share = EROFS_I(inode);

	spin_lock(&vi_share->ishare_lock);

	/* fetch any one as real inode */

	DBG_BUGON(list_empty(&vi_share->ishare_list));

	list_for_each_entry(vi, &vi_share->ishare_list, ishare_list) {

		realinode = igrab(&vi->vfs_inode);

		if (realinode) {

			*need_iput = true;

			break;

		}

	}

	spin_unlock(&vi_share->ishare_lock);



	DBG_BUGON(!realinode);

	return realinode;

}



int __init erofs_init_ishare(void)

{

	erofs_ishare_mnt = kern_mount(&erofs_anon_fs_type);