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-rw-r--r--fs/fs-writeback.c38
-rw-r--r--include/trace/events/writeback.h91
-rw-r--r--mm/backing-dev.c3
3 files changed, 124 insertions, 8 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index c8471b3ddcc..73acab4dc2b 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -26,15 +26,9 @@
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include <linux/buffer_head.h>
+#include <linux/tracepoint.h>
#include "internal.h"
-#define inode_to_bdi(inode) ((inode)->i_mapping->backing_dev_info)
-
-/*
- * We don't actually have pdflush, but this one is exported though /proc...
- */
-int nr_pdflush_threads;
-
/*
* Passed into wb_writeback(), essentially a subset of writeback_control
*/
@@ -50,6 +44,21 @@ struct wb_writeback_work {
struct completion *done; /* set if the caller waits */
};
+/*
+ * Include the creation of the trace points after defining the
+ * wb_writeback_work structure so that the definition remains local to this
+ * file.
+ */
+#define CREATE_TRACE_POINTS
+#include <trace/events/writeback.h>
+
+#define inode_to_bdi(inode) ((inode)->i_mapping->backing_dev_info)
+
+/*
+ * We don't actually have pdflush, but this one is exported though /proc...
+ */
+int nr_pdflush_threads;
+
/**
* writeback_in_progress - determine whether there is writeback in progress
* @bdi: the device's backing_dev_info structure.
@@ -65,6 +74,8 @@ int writeback_in_progress(struct backing_dev_info *bdi)
static void bdi_queue_work(struct backing_dev_info *bdi,
struct wb_writeback_work *work)
{
+ trace_writeback_queue(bdi, work);
+
spin_lock(&bdi->wb_lock);
list_add_tail(&work->list, &bdi->work_list);
spin_unlock(&bdi->wb_lock);
@@ -74,6 +85,7 @@ static void bdi_queue_work(struct backing_dev_info *bdi,
* it gets created and wakes up, we'll run this work.
*/
if (unlikely(!bdi->wb.task)) {
+ trace_writeback_nothread(bdi, work);
wake_up_process(default_backing_dev_info.wb.task);
} else {
struct bdi_writeback *wb = &bdi->wb;
@@ -95,8 +107,10 @@ __bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
*/
work = kzalloc(sizeof(*work), GFP_ATOMIC);
if (!work) {
- if (bdi->wb.task)
+ if (bdi->wb.task) {
+ trace_writeback_nowork(bdi);
wake_up_process(bdi->wb.task);
+ }
return;
}
@@ -751,6 +765,8 @@ long wb_do_writeback(struct bdi_writeback *wb, int force_wait)
if (force_wait)
work->sync_mode = WB_SYNC_ALL;
+ trace_writeback_exec(bdi, work);
+
wrote += wb_writeback(wb, work);
/*
@@ -805,9 +821,13 @@ int bdi_writeback_thread(void *data)
smp_mb__after_clear_bit();
wake_up_bit(&bdi->state, BDI_pending);
+ trace_writeback_thread_start(bdi);
+
while (!kthread_should_stop()) {
pages_written = wb_do_writeback(wb, 0);
+ trace_writeback_pages_written(pages_written);
+
if (pages_written)
last_active = jiffies;
else if (wait_jiffies != -1UL) {
@@ -845,6 +865,8 @@ int bdi_writeback_thread(void *data)
*/
if (!list_empty(&bdi->work_list))
wb_do_writeback(wb, 1);
+
+ trace_writeback_thread_stop(bdi);
return 0;
}
diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h
new file mode 100644
index 00000000000..562fcae10d9
--- /dev/null
+++ b/include/trace/events/writeback.h
@@ -0,0 +1,91 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM writeback
+
+#if !defined(_TRACE_WRITEBACK_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_WRITEBACK_H
+
+#include <linux/backing-dev.h>
+#include <linux/writeback.h>
+
+struct wb_writeback_work;
+
+DECLARE_EVENT_CLASS(writeback_work_class,
+ TP_PROTO(struct backing_dev_info *bdi, struct wb_writeback_work *work),
+ TP_ARGS(bdi, work),
+ TP_STRUCT__entry(
+ __array(char, name, 32)
+ __field(long, nr_pages)
+ __field(dev_t, sb_dev)
+ __field(int, sync_mode)
+ __field(int, for_kupdate)
+ __field(int, range_cyclic)
+ __field(int, for_background)
+ ),
+ TP_fast_assign(
+ strncpy(__entry->name, dev_name(bdi->dev), 32);
+ __entry->nr_pages = work->nr_pages;
+ __entry->sb_dev = work->sb ? work->sb->s_dev : 0;
+ __entry->sync_mode = work->sync_mode;
+ __entry->for_kupdate = work->for_kupdate;
+ __entry->range_cyclic = work->range_cyclic;
+ __entry->for_background = work->for_background;
+ ),
+ TP_printk("bdi %s: sb_dev %d:%d nr_pages=%ld sync_mode=%d "
+ "kupdate=%d range_cyclic=%d background=%d",
+ __entry->name,
+ MAJOR(__entry->sb_dev), MINOR(__entry->sb_dev),
+ __entry->nr_pages,
+ __entry->sync_mode,
+ __entry->for_kupdate,
+ __entry->range_cyclic,
+ __entry->for_background
+ )
+);
+#define DEFINE_WRITEBACK_WORK_EVENT(name) \
+DEFINE_EVENT(writeback_work_class, name, \
+ TP_PROTO(struct backing_dev_info *bdi, struct wb_writeback_work *work), \
+ TP_ARGS(bdi, work))
+DEFINE_WRITEBACK_WORK_EVENT(writeback_nothread);
+DEFINE_WRITEBACK_WORK_EVENT(writeback_queue);
+DEFINE_WRITEBACK_WORK_EVENT(writeback_exec);
+
+TRACE_EVENT(writeback_pages_written,
+ TP_PROTO(long pages_written),
+ TP_ARGS(pages_written),
+ TP_STRUCT__entry(
+ __field(long, pages)
+ ),
+ TP_fast_assign(
+ __entry->pages = pages_written;
+ ),
+ TP_printk("%ld", __entry->pages)
+);
+
+DECLARE_EVENT_CLASS(writeback_class,
+ TP_PROTO(struct backing_dev_info *bdi),
+ TP_ARGS(bdi),
+ TP_STRUCT__entry(
+ __array(char, name, 32)
+ ),
+ TP_fast_assign(
+ strncpy(__entry->name, dev_name(bdi->dev), 32);
+ ),
+ TP_printk("bdi %s",
+ __entry->name
+ )
+);
+#define DEFINE_WRITEBACK_EVENT(name) \
+DEFINE_EVENT(writeback_class, name, \
+ TP_PROTO(struct backing_dev_info *bdi), \
+ TP_ARGS(bdi))
+
+DEFINE_WRITEBACK_EVENT(writeback_nowork);
+DEFINE_WRITEBACK_EVENT(writeback_bdi_register);
+DEFINE_WRITEBACK_EVENT(writeback_bdi_unregister);
+DEFINE_WRITEBACK_EVENT(writeback_thread_start);
+DEFINE_WRITEBACK_EVENT(writeback_thread_stop);
+
+#endif /* _TRACE_WRITEBACK_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index bceac647e4d..ac78a333618 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -10,6 +10,7 @@
#include <linux/module.h>
#include <linux/writeback.h>
#include <linux/device.h>
+#include <trace/events/writeback.h>
static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0);
@@ -518,6 +519,7 @@ int bdi_register(struct backing_dev_info *bdi, struct device *parent,
bdi_debug_register(bdi, dev_name(dev));
set_bit(BDI_registered, &bdi->state);
+ trace_writeback_bdi_register(bdi);
exit:
return ret;
}
@@ -578,6 +580,7 @@ static void bdi_prune_sb(struct backing_dev_info *bdi)
void bdi_unregister(struct backing_dev_info *bdi)
{
if (bdi->dev) {
+ trace_writeback_bdi_unregister(bdi);
bdi_prune_sb(bdi);
if (!bdi_cap_flush_forker(bdi))