On 2025/12/23 16:15, Gao Xiang wrote:
On 2025/12/23 09:56, 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 <[email protected]>
Signed-off-by: Hongzhen Luo <[email protected]>
Signed-off-by: Hongbo Li <[email protected]>
---
...
index 4b46016bcd03..269b53b3ed79 100644
--- a/fs/erofs/ishare.c
+++ b/fs/erofs/ishare.c
@@ -197,6 +197,37 @@ const struct file_operations erofs_ishare_fops = {
.splice_read = filemap_splice_read,
};
+/*
+ * erofs_ishare_iget - find the backing inode.
+ */
+struct inode *erofs_ishare_iget(struct inode *inode)
Just:
struct inode *erofs_get_real_inode(struct inode *inode)
`ishare_` prefix seems useless here.
+{
+ struct erofs_inode *vi, *vi_dedup;
+ struct inode *realinode;
+
+ if (!erofs_is_ishare_inode(inode))
+ return igrab(inode);
Also please `return inode;` directly if `erofs_is_ishare_inode`
is off.
No need to bump the inode reference unnecessarily if ishare is off;
+
+ 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)
Just:
erofs_put_real_inode().
Thanks,
Gao Xiang
