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>
---
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
