[PATCH v3 0/2] Introduce tracepoint for hugetlbfs

[PATCH v3 0/2] Introduce tracepoint for hugetlbfs

[Hongbo Li]

Here we add some basic tracepoints for debugging hugetlbfs: {alloc, free,
evict}_inode, setattr and fallocate.

v2 can be found at:
https://lore.kernel.org/all/ZoYY-sfj5jvs8UpQ@casper.infradead.org/T/

Changes since v2:
  - Simplify the tracepoint output for setattr.
  - Make every token be space separated.


v1 can be found at:
https://lore.kernel.org/linux-mm/20240701194906.3a9b6765@gandalf.local.home/T/

Changes since v1:
  - Decrease the parameters for setattr tracer suggested by Steve and Mathieu.
  - Replace current_user_ns() with init_user_ns when translate uid/gid.

Hongbo Li (2):
  hugetlbfs: support tracepoint
  hugetlbfs: use tracepoints in hugetlbfs functions.

 MAINTAINERS                      |   1 +
 fs/hugetlbfs/inode.c             |  17 +++-
 include/trace/events/hugetlbfs.h | 156 +++++++++++++++++++++++++++++++
 3 files changed, 172 insertions(+), 2 deletions(-)
 create mode 100644 include/trace/events/hugetlbfs.h

-- 
2.34.1

[PATCH v3 1/2] hugetlbfs: support tracepoint

[Hongbo Li]

Add basic tracepoints for {alloc, evict, free}_inode, setattr and
fallocate. These can help users to debug hugetlbfs more conveniently.

Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
---
 MAINTAINERS                      |   1 +
 include/trace/events/hugetlbfs.h | 156 +++++++++++++++++++++++++++++++
 2 files changed, 157 insertions(+)
 create mode 100644 include/trace/events/hugetlbfs.h

diff --git a/MAINTAINERS b/MAINTAINERS
index a0baccca11de..362e846e1294 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10351,6 +10351,7 @@ F:	Documentation/mm/hugetlbfs_reserv.rst
 F:	Documentation/mm/vmemmap_dedup.rst
 F:	fs/hugetlbfs/
 F:	include/linux/hugetlb.h
+F:	include/trace/events/hugetlbfs.h
 F:	mm/hugetlb.c
 F:	mm/hugetlb_vmemmap.c
 F:	mm/hugetlb_vmemmap.h
diff --git a/include/trace/events/hugetlbfs.h b/include/trace/events/hugetlbfs.h
new file mode 100644
index 000000000000..8331c904a9ba
--- /dev/null
+++ b/include/trace/events/hugetlbfs.h
@@ -0,0 +1,156 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM hugetlbfs
+
+#if !defined(_TRACE_HUGETLBFS_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_HUGETLBFS_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(hugetlbfs_alloc_inode,
+
+	TP_PROTO(struct inode *inode, struct inode *dir, int mode),
+
+	TP_ARGS(inode, dir, mode),
+
+	TP_STRUCT__entry(
+		__field(dev_t,		dev)
+		__field(ino_t,		ino)
+		__field(ino_t,		dir)
+		__field(__u16,		mode)
+	),
+
+	TP_fast_assign(
+		__entry->dev		= inode->i_sb->s_dev;
+		__entry->ino		= inode->i_ino;
+		__entry->dir		= dir->i_ino;
+		__entry->mode		= mode;
+	),
+
+	TP_printk("dev %d,%d ino %lu dir %lu mode 0%o",
+		MAJOR(__entry->dev), MINOR(__entry->dev),
+		(unsigned long) __entry->ino,
+		(unsigned long) __entry->dir, __entry->mode)
+);
+
+DECLARE_EVENT_CLASS(hugetlbfs__inode,
+
+	TP_PROTO(struct inode *inode),
+
+	TP_ARGS(inode),
+
+	TP_STRUCT__entry(
+		__field(dev_t,		dev)
+		__field(ino_t,		ino)
+		__field(__u16,		mode)
+		__field(loff_t,		size)
+		__field(unsigned int,	nlink)
+		__field(unsigned int,	seals)
+		__field(blkcnt_t,	blocks)
+	),
+
+	TP_fast_assign(
+		__entry->dev		= inode->i_sb->s_dev;
+		__entry->ino		= inode->i_ino;
+		__entry->mode		= inode->i_mode;
+		__entry->size		= inode->i_size;
+		__entry->nlink		= inode->i_nlink;
+		__entry->seals		= HUGETLBFS_I(inode)->seals;
+		__entry->blocks		= inode->i_blocks;
+	),
+
+	TP_printk("dev %d,%d ino %lu mode 0%o size %lld nlink %u seals %u blocks %llu",
+		MAJOR(__entry->dev), MINOR(__entry->dev), (unsigned long) __entry->ino,
+		__entry->mode, __entry->size, __entry->nlink, __entry->seals,
+		(unsigned long long)__entry->blocks)
+);
+
+DEFINE_EVENT(hugetlbfs__inode, hugetlbfs_evict_inode,
+
+	TP_PROTO(struct inode *inode),
+
+	TP_ARGS(inode)
+);
+
+DEFINE_EVENT(hugetlbfs__inode, hugetlbfs_free_inode,
+
+	TP_PROTO(struct inode *inode),
+
+	TP_ARGS(inode)
+);
+
+TRACE_EVENT(hugetlbfs_setattr,
+
+	TP_PROTO(struct inode *inode, struct dentry *dentry,
+		struct iattr *attr),
+
+	TP_ARGS(inode, dentry, attr),
+
+	TP_STRUCT__entry(
+		__field(dev_t,		dev)
+		__field(ino_t,		ino)
+		__field(unsigned int,	d_len)
+		__string(d_name,	dentry->d_name.name)
+		__field(unsigned int,	ia_valid)
+		__field(unsigned int,	ia_mode)
+		__field(loff_t,		old_size)
+		__field(loff_t,		ia_size)
+	),
+
+	TP_fast_assign(
+		__entry->dev		= inode->i_sb->s_dev;
+		__entry->ino		= inode->i_ino;
+		__entry->d_len		= dentry->d_name.len;
+		__assign_str(d_name);
+		__entry->ia_valid	= attr->ia_valid;
+		__entry->ia_mode	= attr->ia_mode;
+		__entry->old_size	= inode->i_size;
+		__entry->ia_size	= attr->ia_size;
+	),
+
+	TP_printk("dev %d,%d ino %lu name %.*s valid %#x mode 0%o old_size %lld size %lld",
+		MAJOR(__entry->dev), MINOR(__entry->dev), (unsigned long)__entry->ino,
+		__entry->d_len, __get_str(d_name), __entry->ia_valid, __entry->ia_mode,
+		__entry->old_size, __entry->ia_size)
+);
+
+TRACE_EVENT(hugetlbfs_fallocate,
+
+	TP_PROTO(struct inode *inode, int mode,
+		loff_t offset, loff_t len, int ret),
+
+	TP_ARGS(inode, mode, offset, len, ret),
+
+	TP_STRUCT__entry(
+		__field(dev_t,		dev)
+		__field(ino_t,		ino)
+		__field(int,		mode)
+		__field(loff_t,		offset)
+		__field(loff_t,		len)
+		__field(loff_t,		size)
+		__field(int,		ret)
+	),
+
+	TP_fast_assign(
+		__entry->dev		= inode->i_sb->s_dev;
+		__entry->ino		= inode->i_ino;
+		__entry->mode		= mode;
+		__entry->offset		= offset;
+		__entry->len		= len;
+		__entry->size		= inode->i_size;
+		__entry->ret		= ret;
+	),
+
+	TP_printk("dev %d,%d ino %lu mode 0%o offset %lld len %lld size %lld ret %d",
+		MAJOR(__entry->dev), MINOR(__entry->dev),
+		(unsigned long)__entry->ino, __entry->mode,
+		(unsigned long long)__entry->offset,
+		(unsigned long long)__entry->len,
+		(unsigned long long)__entry->size,
+		__entry->ret)
+);
+
+#endif /* _TRACE_HUGETLBFS_H */
+
+ /* This part must be outside protection */
+#include <trace/define_trace.h>
-- 
2.34.1

[PATCH v3 2/2] hugetlbfs: use tracepoints in hugetlbfs functions.

[Hongbo Li]

Here we use the hugetlbfs tracepoint to track the call stack. And
the output in trace is as follows:

```
   touch-5265    [005] .....    43.246550: hugetlbfs_alloc_inode: dev 0,51 ino 24621 dir 21959 mode 0100644
   touch-5265    [005] .....    43.246638: hugetlbfs_setattr: dev 0,51 ino 24621 name testfile valid 0x20070 mode 0177777 old_size 0 size -51622648042749952
truncate-5266    [005] .....    45.590890: hugetlbfs_setattr: dev 0,51 ino 24621 name testfile valid 0x2068 mode 00 old_size 0 size 2097152
rm-5273    [007] .....   110.052783: hugetlbfs_evict_inode: dev 0,51 ino 24621 mode 0100644 size 2097152 nlink 0 seals 1 blocks 0
  <idle>-0       [007] ..s1.   110.059441: hugetlbfs_free_inode: dev 0,51 ino 24621 mode 0100644 size 2097152 nlink 0 seals 1 blocks 0
```

Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
---
 fs/hugetlbfs/inode.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 9f6cff356796..1689c01a11a0 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -39,6 +39,9 @@
 #include <linux/uaccess.h>
 #include <linux/sched/mm.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/hugetlbfs.h>
+
 static const struct address_space_operations hugetlbfs_aops;
 static const struct file_operations hugetlbfs_file_operations;
 static const struct inode_operations hugetlbfs_dir_inode_operations;
@@ -687,6 +690,7 @@ static void hugetlbfs_evict_inode(struct inode *inode)
 {
 	struct resv_map *resv_map;
 
+	trace_hugetlbfs_evict_inode(inode);
 	remove_inode_hugepages(inode, 0, LLONG_MAX);
 
 	/*
@@ -814,8 +818,10 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
 	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
 		return -EOPNOTSUPP;
 
-	if (mode & FALLOC_FL_PUNCH_HOLE)
-		return hugetlbfs_punch_hole(inode, offset, len);
+	if (mode & FALLOC_FL_PUNCH_HOLE) {
+		error = hugetlbfs_punch_hole(inode, offset, len);
+		goto out_nolock;
+	}
 
 	/*
 	 * Default preallocate case.
@@ -919,6 +925,9 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
 	inode_set_ctime_current(inode);
 out:
 	inode_unlock(inode);
+
+out_nolock:
+	trace_hugetlbfs_fallocate(inode, mode, offset, len, error);
 	return error;
 }
 
@@ -935,6 +944,8 @@ static int hugetlbfs_setattr(struct mnt_idmap *idmap,
 	if (error)
 		return error;
 
+	trace_hugetlbfs_setattr(inode, dentry, attr);
+
 	if (ia_valid & ATTR_SIZE) {
 		loff_t oldsize = inode->i_size;
 		loff_t newsize = attr->ia_size;
@@ -1033,6 +1044,7 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb,
 			break;
 		}
 		lockdep_annotate_inode_mutex_key(inode);
+		trace_hugetlbfs_alloc_inode(inode, dir, mode);
 	} else {
 		if (resv_map)
 			kref_put(&resv_map->refs, resv_map_release);
@@ -1272,6 +1284,7 @@ static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
 
 static void hugetlbfs_free_inode(struct inode *inode)
 {
+	trace_hugetlbfs_free_inode(inode);
 	kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
 }
 
-- 
2.34.1

Re: [PATCH v3 0/2] Introduce tracepoint for hugetlbfs

[Hongbo Li]

Give you a friendly ping.🙂

Thanks,
Hongbo

On 2024/7/23 11:08, Hongbo Li wrote:
> Here we add some basic tracepoints for debugging hugetlbfs: {alloc, free,
> evict}_inode, setattr and fallocate.
> 
> v2 can be found at:
> https://lore.kernel.org/all/ZoYY-sfj5jvs8UpQ@casper.infradead.org/T/
> 
> Changes since v2:
>    - Simplify the tracepoint output for setattr.
>    - Make every token be space separated.
> 
> 
> v1 can be found at:
> https://lore.kernel.org/linux-mm/20240701194906.3a9b6765@gandalf.local.home/T/
> 
> Changes since v1:
>    - Decrease the parameters for setattr tracer suggested by Steve and Mathieu.
>    - Replace current_user_ns() with init_user_ns when translate uid/gid.
> 
> Hongbo Li (2):
>    hugetlbfs: support tracepoint
>    hugetlbfs: use tracepoints in hugetlbfs functions.
> 
>   MAINTAINERS                      |   1 +
>   fs/hugetlbfs/inode.c             |  17 +++-
>   include/trace/events/hugetlbfs.h | 156 +++++++++++++++++++++++++++++++
>   3 files changed, 172 insertions(+), 2 deletions(-)
>   create mode 100644 include/trace/events/hugetlbfs.h
>