Re: [RFC 8/9] ext4: Convert ext4_fc_track_dentry type events to use event class

From: Jan Kara
Date: Wed Feb 23 2022 - 04:49:41 EST


On Wed 23-02-22 02:04:16, Ritesh Harjani wrote:
> One should use DECLARE_EVENT_CLASS for similar event types instead of
> defining TRACE_EVENT for each event type. This is helpful in reducing
> the text section footprint for e.g. [1]
>
> [1]: https://lwn.net/Articles/381064/
>
> Signed-off-by: Ritesh Harjani <riteshh@xxxxxxxxxxxxx>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

Honza

> ---
> include/trace/events/ext4.h | 57 +++++++++++++++++++++----------------
> 1 file changed, 32 insertions(+), 25 deletions(-)
>
> diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h
> index 233dbffa5ceb..33a059d845d6 100644
> --- a/include/trace/events/ext4.h
> +++ b/include/trace/events/ext4.h
> @@ -2783,33 +2783,40 @@ TRACE_EVENT(ext4_fc_stats,
> __entry->fc_numblks)
> );
>
> -#define DEFINE_TRACE_DENTRY_EVENT(__type) \
> - TRACE_EVENT(ext4_fc_track_##__type, \
> - TP_PROTO(struct inode *inode, struct dentry *dentry, int ret), \
> - \
> - TP_ARGS(inode, dentry, ret), \
> - \
> - TP_STRUCT__entry( \
> - __field(dev_t, dev) \
> - __field(int, ino) \
> - __field(int, error) \
> - ), \
> - \
> - TP_fast_assign( \
> - __entry->dev = inode->i_sb->s_dev; \
> - __entry->ino = inode->i_ino; \
> - __entry->error = ret; \
> - ), \
> - \
> - TP_printk("dev %d:%d, inode %d, error %d, fc_%s", \
> - MAJOR(__entry->dev), MINOR(__entry->dev), \
> - __entry->ino, __entry->error, \
> - #__type) \
> +DECLARE_EVENT_CLASS(ext4_fc_track_dentry,
> +
> + TP_PROTO(struct inode *inode, struct dentry *dentry, int ret),
> +
> + TP_ARGS(inode, dentry, ret),
> +
> + TP_STRUCT__entry(
> + __field(dev_t, dev)
> + __field(int, ino)
> + __field(int, error)
> + ),
> +
> + TP_fast_assign(
> + __entry->dev = inode->i_sb->s_dev;
> + __entry->ino = inode->i_ino;
> + __entry->error = ret;
> + ),
> +
> + TP_printk("dev %d,%d, inode %d, error %d",
> + MAJOR(__entry->dev), MINOR(__entry->dev),
> + __entry->ino, __entry->error
> )
> +);
> +
> +#define DEFINE_EVENT_CLASS_TYPE(__type) \
> +DEFINE_EVENT(ext4_fc_track_dentry, ext4_fc_track_##__type, \
> + TP_PROTO(struct inode *inode, struct dentry *dentry, int ret), \
> + TP_ARGS(inode, dentry, ret) \
> +)
> +
>
> -DEFINE_TRACE_DENTRY_EVENT(create);
> -DEFINE_TRACE_DENTRY_EVENT(link);
> -DEFINE_TRACE_DENTRY_EVENT(unlink);
> +DEFINE_EVENT_CLASS_TYPE(create);
> +DEFINE_EVENT_CLASS_TYPE(link);
> +DEFINE_EVENT_CLASS_TYPE(unlink);
>
> TRACE_EVENT(ext4_fc_track_inode,
> TP_PROTO(struct inode *inode, int ret),
> --
> 2.31.1
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR