writeback: add more tracepoints

Add tracepoints for page dirtying, writeback_single_inode start, inode
dirtying and writeback.  For the latter two inode events, a pair of
events are defined to denote start and end of the operations (the
starting one has _start suffix and the one w/o suffix happens after
the operation is complete).  These inode ops are FS specific and can
be non-trivial and having enclosing tracepoints is useful for external
tracers.

This is part of tracepoint additions to improve visiblity into
dirtying / writeback operations for io tracer and userland.

v2: writeback_dirty_inode[_start] TPs may be called for files on
    pseudo FSes w/ unregistered bdi.  Check whether bdi->dev is %NULL
    before dereferencing.

v3: buffer dirtying moved to a block TP.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Tejun Heo 2013-01-11 13:06:37 -08:00 committed by Jens Axboe
parent 5305cb8308
commit 9fb0a7da0c
3 changed files with 132 additions and 2 deletions

View file

@ -318,8 +318,14 @@ static void queue_io(struct bdi_writeback *wb, struct wb_writeback_work *work)
static int write_inode(struct inode *inode, struct writeback_control *wbc)
{
if (inode->i_sb->s_op->write_inode && !is_bad_inode(inode))
return inode->i_sb->s_op->write_inode(inode, wbc);
int ret;
if (inode->i_sb->s_op->write_inode && !is_bad_inode(inode)) {
trace_writeback_write_inode_start(inode, wbc);
ret = inode->i_sb->s_op->write_inode(inode, wbc);
trace_writeback_write_inode(inode, wbc);
return ret;
}
return 0;
}
@ -450,6 +456,8 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
WARN_ON(!(inode->i_state & I_SYNC));
trace_writeback_single_inode_start(inode, wbc, nr_to_write);
ret = do_writepages(mapping, wbc);
/*
@ -1150,8 +1158,12 @@ void __mark_inode_dirty(struct inode *inode, int flags)
* dirty the inode itself
*/
if (flags & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) {
trace_writeback_dirty_inode_start(inode, flags);
if (sb->s_op->dirty_inode)
sb->s_op->dirty_inode(inode, flags);
trace_writeback_dirty_inode(inode, flags);
}
/*

View file

@ -32,6 +32,115 @@
struct wb_writeback_work;
TRACE_EVENT(writeback_dirty_page,
TP_PROTO(struct page *page, struct address_space *mapping),
TP_ARGS(page, mapping),
TP_STRUCT__entry (
__array(char, name, 32)
__field(unsigned long, ino)
__field(pgoff_t, index)
),
TP_fast_assign(
strncpy(__entry->name,
mapping ? dev_name(mapping->backing_dev_info->dev) : "(unknown)", 32);
__entry->ino = mapping ? mapping->host->i_ino : 0;
__entry->index = page->index;
),
TP_printk("bdi %s: ino=%lu index=%lu",
__entry->name,
__entry->ino,
__entry->index
)
);
DECLARE_EVENT_CLASS(writeback_dirty_inode_template,
TP_PROTO(struct inode *inode, int flags),
TP_ARGS(inode, flags),
TP_STRUCT__entry (
__array(char, name, 32)
__field(unsigned long, ino)
__field(unsigned long, flags)
),
TP_fast_assign(
struct backing_dev_info *bdi = inode->i_mapping->backing_dev_info;
/* may be called for files on pseudo FSes w/ unregistered bdi */
strncpy(__entry->name,
bdi->dev ? dev_name(bdi->dev) : "(unknown)", 32);
__entry->ino = inode->i_ino;
__entry->flags = flags;
),
TP_printk("bdi %s: ino=%lu flags=%s",
__entry->name,
__entry->ino,
show_inode_state(__entry->flags)
)
);
DEFINE_EVENT(writeback_dirty_inode_template, writeback_dirty_inode_start,
TP_PROTO(struct inode *inode, int flags),
TP_ARGS(inode, flags)
);
DEFINE_EVENT(writeback_dirty_inode_template, writeback_dirty_inode,
TP_PROTO(struct inode *inode, int flags),
TP_ARGS(inode, flags)
);
DECLARE_EVENT_CLASS(writeback_write_inode_template,
TP_PROTO(struct inode *inode, struct writeback_control *wbc),
TP_ARGS(inode, wbc),
TP_STRUCT__entry (
__array(char, name, 32)
__field(unsigned long, ino)
__field(int, sync_mode)
),
TP_fast_assign(
strncpy(__entry->name,
dev_name(inode->i_mapping->backing_dev_info->dev), 32);
__entry->ino = inode->i_ino;
__entry->sync_mode = wbc->sync_mode;
),
TP_printk("bdi %s: ino=%lu sync_mode=%d",
__entry->name,
__entry->ino,
__entry->sync_mode
)
);
DEFINE_EVENT(writeback_write_inode_template, writeback_write_inode_start,
TP_PROTO(struct inode *inode, struct writeback_control *wbc),
TP_ARGS(inode, wbc)
);
DEFINE_EVENT(writeback_write_inode_template, writeback_write_inode,
TP_PROTO(struct inode *inode, struct writeback_control *wbc),
TP_ARGS(inode, wbc)
);
DECLARE_EVENT_CLASS(writeback_work_class,
TP_PROTO(struct backing_dev_info *bdi, struct wb_writeback_work *work),
TP_ARGS(bdi, work),
@ -479,6 +588,13 @@ DECLARE_EVENT_CLASS(writeback_single_inode_template,
)
);
DEFINE_EVENT(writeback_single_inode_template, writeback_single_inode_start,
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,

View file

@ -1982,6 +1982,8 @@ int __set_page_dirty_no_writeback(struct page *page)
*/
void account_page_dirtied(struct page *page, struct address_space *mapping)
{
trace_writeback_dirty_page(page, mapping);
if (mapping_cap_account_dirty(mapping)) {
__inc_zone_page_state(page, NR_FILE_DIRTY);
__inc_zone_page_state(page, NR_DIRTIED);