I have used this tracepoint for verifying other patches in the series. Useful. The patch looks good.
Reviewed-by: Artem Blagodarenko <artem.blagodarenko@xxxxxxxxx>
> On 17 Jul 2020, at 18:53, Theodore Ts'o <tytso@xxxxxxx> wrote:
>
> Modify the ext4_read_block_bitmap_load tracepoint so that it tells us
> whether a block bitmap is being prefetched.
>
> Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
> ---
> fs/ext4/balloc.c | 2 +-
> include/trace/events/ext4.h | 24 ++++++++++++++++++++----
> 2 files changed, 21 insertions(+), 5 deletions(-)
>
> diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
> index aaa9ec5212c8..5a2f8837200c 100644
> --- a/fs/ext4/balloc.c
> +++ b/fs/ext4/balloc.c
> @@ -494,7 +494,7 @@ ext4_read_block_bitmap_nowait(struct super_block *sb, ext4_group_t block_group,
> * submit the buffer_head for reading
> */
> set_buffer_new(bh);
> - trace_ext4_read_block_bitmap_load(sb, block_group);
> + trace_ext4_read_block_bitmap_load(sb, block_group, ignore_locked);
> bh->b_end_io = ext4_end_bitmap_read;
> get_bh(bh);
> submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO |
> diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h
> index cc41d692ae8e..cbcd2e1a608d 100644
> --- a/include/trace/events/ext4.h
> +++ b/include/trace/events/ext4.h
> @@ -1312,18 +1312,34 @@ DEFINE_EVENT(ext4__bitmap_load, ext4_mb_buddy_bitmap_load,
> TP_ARGS(sb, group)
> );
>
> -DEFINE_EVENT(ext4__bitmap_load, ext4_read_block_bitmap_load,
> +DEFINE_EVENT(ext4__bitmap_load, ext4_load_inode_bitmap,
>
> TP_PROTO(struct super_block *sb, unsigned long group),
>
> TP_ARGS(sb, group)
> );
>
> -DEFINE_EVENT(ext4__bitmap_load, ext4_load_inode_bitmap,
> +TRACE_EVENT(ext4_read_block_bitmap_load,
> + TP_PROTO(struct super_block *sb, unsigned long group, bool prefetch),
>
> - TP_PROTO(struct super_block *sb, unsigned long group),
> + TP_ARGS(sb, group, prefetch),
>
> - TP_ARGS(sb, group)
> + TP_STRUCT__entry(
> + __field( dev_t, dev )
> + __field( __u32, group )
> + __field( bool, prefetch )
> +
> + ),
> +
> + TP_fast_assign(
> + __entry->dev = sb->s_dev;
> + __entry->group = group;
> + __entry->prefetch = prefetch;
> + ),
> +
> + TP_printk("dev %d,%d group %u prefetch %d",
> + MAJOR(__entry->dev), MINOR(__entry->dev),
> + __entry->group, __entry->prefetch)
> );
>
> TRACE_EVENT(ext4_direct_IO_enter,
> --
> 2.24.1
>
