On Tue, 28 Jul 2026 17:44:21 +0800
Baolin Liu <[email protected]> wrote:
> diff --git a/include/trace/events/ntfs3.h b/include/trace/events/ntfs3.h
> index d00f66e42ba8..041455edec76 100644
> --- a/include/trace/events/ntfs3.h
> +++ b/include/trace/events/ntfs3.h
> @@ -80,6 +80,50 @@ TRACE_EVENT(ntfs3_log_replay,
> __entry->size, __entry->initialized, __entry->err)
> );
>
> +TRACE_EVENT(ntfs3_lookup,
> + TP_PROTO(struct inode *dir, struct dentry *dentry),
> + TP_ARGS(dir, dentry),
> + TP_STRUCT__entry(
> + __field(dev_t, dev)
dev_t is 4 bytes, you should move it after parent_ino as on 64 bit
machines, it will waste 4 bytes of space here.
> + __field(unsigned long, parent_ino)
> + __string(name, dentry->d_name.name)
> + ),
> + TP_fast_assign(
> + __entry->dev = dir->i_sb->s_dev;
> + __entry->parent_ino = dir->i_ino;
> + __assign_str(name);
> + ),
> + TP_printk("dev=(%d,%d) parent=%lu name=%s",
> + MAJOR(__entry->dev), MINOR(__entry->dev),
> + __entry->parent_ino, __get_str(name))
> +);
> +
> +TRACE_EVENT(ntfs3_rename,
> + TP_PROTO(struct inode *dir, struct dentry *dentry,
> + struct inode *new_dir, struct dentry *new_dentry),
> + TP_ARGS(dir, dentry, new_dir, new_dentry),
> + TP_STRUCT__entry(
> + __field(dev_t, dev)
Same here.
In fact, you should audit the rest of your tracepoints to see where you can
make the sizes more condensed.
~# cat /sys/kernel/tracing/events/ntfs3/ntfs3_rename/format
name: ntfs3_rename
ID: 1923
format:
field:unsigned short common_type; offset:0; size:2;
signed:0;
field:unsigned char common_flags; offset:2; size:1;
signed:0;
field:unsigned char common_preempt_count; offset:3; size:1;
signed:0;
field:int common_pid; offset:4; size:4; signed:1;
field:dev_t dev; offset:8; size:4; signed:0;
field:unsigned long dir_ino; offset:16; size:8; signed:0;
field:unsigned long new_dir_ino; offset:24; size:8;
signed:0;
field:unsigned long ino; offset:32; size:8; signed:0;
field:__data_loc char[] old_name; offset:40; size:4;
signed:0;
field:__data_loc char[] new_name; offset:44; size:4;
signed:0;
Notice that dev is at offset 8 and size 4, where as dir_ino is at offset
16. That means there's 4 bytes between dev and dir_ino.
Please look at your other trace events and see if there are other gaps you
can close. I'm not going to audit all your tracepoints.
Note that __string() is a 4 byte meta data, so have them act like 4 byte
fields.
-- Steve
> + __field(unsigned long, dir_ino)
> + __field(unsigned long, new_dir_ino)
> + __field(unsigned long, ino)
> + __string(old_name, dentry->d_name.name)
> + __string(new_name, new_dentry->d_name.name)
> + ),
> + TP_fast_assign(
> + __entry->dev = dir->i_sb->s_dev;
> + __entry->dir_ino = dir->i_ino;
> + __entry->new_dir_ino = new_dir->i_ino;
> + __entry->ino = d_inode(dentry)->i_ino;
> + __assign_str(old_name);
> + __assign_str(new_name);
> + ),
> + TP_printk("dev=(%d,%d) dir=%lu new_dir=%lu ino=%lu old=%s new=%s",
> + MAJOR(__entry->dev), MINOR(__entry->dev),
> + __entry->dir_ino, __entry->new_dir_ino, __entry->ino,
> + __get_str(old_name), __get_str(new_name))
> +);
> +
> #endif /* _TRACE_NTFS3_H */
>
