Commit 251d6a47 authored by Wu Fengguang's avatar Wu Fengguang

writeback: trace event writeback_single_inode

It is valuable to know how the dirty inodes are iterated and their IO size.

"writeback_single_inode: bdi 8:0: ino=134246746 state=I_DIRTY_SYNC|I_SYNC age=414 index=0 to_write=1024 wrote=0"

- "state" reflects inode->i_state at the end of writeback_single_inode()
- "index" reflects mapping->writeback_index after the ->writepages() call
- "to_write" is the wbc->nr_to_write at entrance of writeback_single_inode()
- "wrote" is the number of pages actually written

v2: add trace event writeback_single_inode_requeue as proposed by Dave.

CC: Dave Chinner <david@fromorbit.com>
Signed-off-by: default avatarWu Fengguang <fengguang.wu@intel.com>
parent 846d5a09
......@@ -346,6 +346,7 @@ writeback_single_inode(struct inode *inode, struct bdi_writeback *wb,
struct writeback_control *wbc)
{
struct address_space *mapping = inode->i_mapping;
long nr_to_write = wbc->nr_to_write;
unsigned dirty;
int ret;
......@@ -368,6 +369,8 @@ writeback_single_inode(struct inode *inode, struct bdi_writeback *wb,
*/
if (wbc->sync_mode != WB_SYNC_ALL) {
requeue_io(inode, wb);
trace_writeback_single_inode_requeue(inode, wbc,
nr_to_write);
return 0;
}
......@@ -467,6 +470,7 @@ writeback_single_inode(struct inode *inode, struct bdi_writeback *wb,
}
}
inode_sync_complete(inode);
trace_writeback_single_inode(inode, wbc, nr_to_write);
return ret;
}
......
......@@ -8,6 +8,19 @@
#include <linux/device.h>
#include <linux/writeback.h>
#define show_inode_state(state) \
__print_flags(state, "|", \
{I_DIRTY_SYNC, "I_DIRTY_SYNC"}, \
{I_DIRTY_DATASYNC, "I_DIRTY_DATASYNC"}, \
{I_DIRTY_PAGES, "I_DIRTY_PAGES"}, \
{I_NEW, "I_NEW"}, \
{I_WILL_FREE, "I_WILL_FREE"}, \
{I_FREEING, "I_FREEING"}, \
{I_CLEAR, "I_CLEAR"}, \
{I_SYNC, "I_SYNC"}, \
{I_REFERENCED, "I_REFERENCED"} \
)
struct wb_writeback_work;
DECLARE_EVENT_CLASS(writeback_work_class,
......@@ -184,6 +197,63 @@ DEFINE_EVENT(writeback_congest_waited_template, writeback_wait_iff_congested,
TP_ARGS(usec_timeout, usec_delayed)
);
DECLARE_EVENT_CLASS(writeback_single_inode_template,
TP_PROTO(struct inode *inode,
struct writeback_control *wbc,
unsigned long nr_to_write
),
TP_ARGS(inode, wbc, nr_to_write),
TP_STRUCT__entry(
__array(char, name, 32)
__field(unsigned long, ino)
__field(unsigned long, state)
__field(unsigned long, age)
__field(unsigned long, writeback_index)
__field(long, nr_to_write)
__field(unsigned long, wrote)
),
TP_fast_assign(
strncpy(__entry->name,
dev_name(inode->i_mapping->backing_dev_info->dev), 32);
__entry->ino = inode->i_ino;
__entry->state = inode->i_state;
__entry->age = (jiffies - inode->dirtied_when) *
1000 / HZ;
__entry->writeback_index = inode->i_mapping->writeback_index;
__entry->nr_to_write = nr_to_write;
__entry->wrote = nr_to_write - wbc->nr_to_write;
),
TP_printk("bdi %s: ino=%lu state=%s age=%lu "
"index=%lu to_write=%ld wrote=%lu",
__entry->name,
__entry->ino,
show_inode_state(__entry->state),
__entry->age,
__entry->writeback_index,
__entry->nr_to_write,
__entry->wrote
)
);
DEFINE_EVENT(writeback_single_inode_template, writeback_single_inode_requeue,
TP_PROTO(struct inode *inode,
struct writeback_control *wbc,
unsigned long nr_to_write),
TP_ARGS(inode, wbc, nr_to_write)
);
DEFINE_EVENT(writeback_single_inode_template, writeback_single_inode,
TP_PROTO(struct inode *inode,
struct writeback_control *wbc,
unsigned long nr_to_write),
TP_ARGS(inode, wbc, nr_to_write)
);
#endif /* _TRACE_WRITEBACK_H */
/* This part must be outside protection */
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment