On Mon 03-03-25 18:06:16, Tang Yizhou wrote:
> From: Tang Yizhou <yizhou.tang@xxxxxxxxxx>
>
> Currently, trace_balance_dirty_pages() already has 12 parameters. In the
> next patch, I initially attempted to introduce an additional parameter.
> However, in include/linux/trace_events.h, bpf_trace_run12() only supports
> up to 12 parameters and bpf_trace_run13() does not exist.
>
> To reduce the number of parameters in trace_balance_dirty_pages(), we can
> make it accept a pointer to struct dirty_throttle_control as a parameter.
> To achieve this, we need to move the definition of struct
> dirty_throttle_control from mm/page-writeback.c to
> include/linux/writeback.h.
>
> By the way, rename bdi_setpoint and bdi_dirty in the tracepoint to
> wb_setpoint and wb_dirty, respectively. These changes were omitted by
> Tejun in the cgroup writeback patchset.
>
> Signed-off-by: Tang Yizhou <yizhou.tang@xxxxxxxxxx>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> include/linux/writeback.h | 23 +++++++++++++++++++++
> include/trace/events/writeback.h | 28 +++++++++++--------------
> mm/page-writeback.c | 35 ++------------------------------
> 3 files changed, 37 insertions(+), 49 deletions(-)
>
> diff --git a/include/linux/writeback.h b/include/linux/writeback.h
> index d11b903c2edb..32095928365c 100644
> --- a/include/linux/writeback.h
> +++ b/include/linux/writeback.h
> @@ -313,6 +313,29 @@ static inline void cgroup_writeback_umount(struct super_block *sb)
> /*
> * mm/page-writeback.c
> */
> +/* consolidated parameters for balance_dirty_pages() and its subroutines */
> +struct dirty_throttle_control {
> +#ifdef CONFIG_CGROUP_WRITEBACK
> + struct wb_domain *dom;
> + struct dirty_throttle_control *gdtc; /* only set in memcg dtc's */
> +#endif
> + struct bdi_writeback *wb;
> + struct fprop_local_percpu *wb_completions;
> +
> + unsigned long avail; /* dirtyable */
> + unsigned long dirty; /* file_dirty + write + nfs */
> + unsigned long thresh; /* dirty threshold */
> + unsigned long bg_thresh; /* dirty background threshold */
> +
> + unsigned long wb_dirty; /* per-wb counterparts */
> + unsigned long wb_thresh;
> + unsigned long wb_bg_thresh;
> +
> + unsigned long pos_ratio;
> + bool freerun;
> + bool dirty_exceeded;
> +};
> +
> void laptop_io_completion(struct backing_dev_info *info);
> void laptop_sync_completion(void);
> void laptop_mode_timer_fn(struct timer_list *t);
> diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h
> index a261e86e61fa..3046ca6b08ea 100644
> --- a/include/trace/events/writeback.h
> +++ b/include/trace/events/writeback.h
> @@ -629,11 +629,7 @@ TRACE_EVENT(bdi_dirty_ratelimit,
> TRACE_EVENT(balance_dirty_pages,
>
> TP_PROTO(struct bdi_writeback *wb,
> - unsigned long thresh,
> - unsigned long bg_thresh,
> - unsigned long dirty,
> - unsigned long bdi_thresh,
> - unsigned long bdi_dirty,
> + struct dirty_throttle_control *dtc,
> unsigned long dirty_ratelimit,
> unsigned long task_ratelimit,
> unsigned long dirtied,
> @@ -641,7 +637,7 @@ TRACE_EVENT(balance_dirty_pages,
> long pause,
> unsigned long start_time),
>
> - TP_ARGS(wb, thresh, bg_thresh, dirty, bdi_thresh, bdi_dirty,
> + TP_ARGS(wb, dtc,
> dirty_ratelimit, task_ratelimit,
> dirtied, period, pause, start_time),
>
> @@ -650,8 +646,8 @@ TRACE_EVENT(balance_dirty_pages,
> __field(unsigned long, limit)
> __field(unsigned long, setpoint)
> __field(unsigned long, dirty)
> - __field(unsigned long, bdi_setpoint)
> - __field(unsigned long, bdi_dirty)
> + __field(unsigned long, wb_setpoint)
> + __field(unsigned long, wb_dirty)
> __field(unsigned long, dirty_ratelimit)
> __field(unsigned long, task_ratelimit)
> __field(unsigned int, dirtied)
> @@ -664,16 +660,16 @@ TRACE_EVENT(balance_dirty_pages,
> ),
>
> TP_fast_assign(
> - unsigned long freerun = (thresh + bg_thresh) / 2;
> + unsigned long freerun = (dtc->thresh + dtc->bg_thresh) / 2;
> strscpy_pad(__entry->bdi, bdi_dev_name(wb->bdi), 32);
>
> __entry->limit = global_wb_domain.dirty_limit;
> __entry->setpoint = (global_wb_domain.dirty_limit +
> freerun) / 2;
> - __entry->dirty = dirty;
> - __entry->bdi_setpoint = __entry->setpoint *
> - bdi_thresh / (thresh + 1);
> - __entry->bdi_dirty = bdi_dirty;
> + __entry->dirty = dtc->dirty;
> + __entry->wb_setpoint = __entry->setpoint *
> + dtc->wb_thresh / (dtc->thresh + 1);
> + __entry->wb_dirty = dtc->wb_dirty;
> __entry->dirty_ratelimit = KBps(dirty_ratelimit);
> __entry->task_ratelimit = KBps(task_ratelimit);
> __entry->dirtied = dirtied;
> @@ -689,7 +685,7 @@ TRACE_EVENT(balance_dirty_pages,
>
> TP_printk("bdi %s: "
> "limit=%lu setpoint=%lu dirty=%lu "
> - "bdi_setpoint=%lu bdi_dirty=%lu "
> + "wb_setpoint=%lu wb_dirty=%lu "
> "dirty_ratelimit=%lu task_ratelimit=%lu "
> "dirtied=%u dirtied_pause=%u "
> "paused=%lu pause=%ld period=%lu think=%ld cgroup_ino=%lu",
> @@ -697,8 +693,8 @@ TRACE_EVENT(balance_dirty_pages,
> __entry->limit,
> __entry->setpoint,
> __entry->dirty,
> - __entry->bdi_setpoint,
> - __entry->bdi_dirty,
> + __entry->wb_setpoint,
> + __entry->wb_dirty,
> __entry->dirty_ratelimit,
> __entry->task_ratelimit,
> __entry->dirtied,
> diff --git a/mm/page-writeback.c b/mm/page-writeback.c
> index eb55ece39c56..e980b2aec352 100644
> --- a/mm/page-writeback.c
> +++ b/mm/page-writeback.c
> @@ -120,29 +120,6 @@ EXPORT_SYMBOL(laptop_mode);
>
> struct wb_domain global_wb_domain;
>
> -/* consolidated parameters for balance_dirty_pages() and its subroutines */
> -struct dirty_throttle_control {
> -#ifdef CONFIG_CGROUP_WRITEBACK
> - struct wb_domain *dom;
> - struct dirty_throttle_control *gdtc; /* only set in memcg dtc's */
> -#endif
> - struct bdi_writeback *wb;
> - struct fprop_local_percpu *wb_completions;
> -
> - unsigned long avail; /* dirtyable */
> - unsigned long dirty; /* file_dirty + write + nfs */
> - unsigned long thresh; /* dirty threshold */
> - unsigned long bg_thresh; /* dirty background threshold */
> -
> - unsigned long wb_dirty; /* per-wb counterparts */
> - unsigned long wb_thresh;
> - unsigned long wb_bg_thresh;
> -
> - unsigned long pos_ratio;
> - bool freerun;
> - bool dirty_exceeded;
> -};
> -
> /*
> * Length of period for aging writeout fractions of bdis. This is an
> * arbitrarily chosen number. The longer the period, the slower fractions will
> @@ -1962,11 +1939,7 @@ static int balance_dirty_pages(struct bdi_writeback *wb,
> */
> if (pause < min_pause) {
> trace_balance_dirty_pages(wb,
> - sdtc->thresh,
> - sdtc->bg_thresh,
> - sdtc->dirty,
> - sdtc->wb_thresh,
> - sdtc->wb_dirty,
> + sdtc,
> dirty_ratelimit,
> task_ratelimit,
> pages_dirtied,
> @@ -1991,11 +1964,7 @@ static int balance_dirty_pages(struct bdi_writeback *wb,
>
> pause:
> trace_balance_dirty_pages(wb,
> - sdtc->thresh,
> - sdtc->bg_thresh,
> - sdtc->dirty,
> - sdtc->wb_thresh,
> - sdtc->wb_dirty,
> + sdtc,
> dirty_ratelimit,
> task_ratelimit,
> pages_dirtied,
> --
> 2.25.1
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
