writeback: Add a 'reason' to wb_writeback_work
This creates a new 'reason' field in a wb_writeback_work
structure, which unambiguously identifies who initiates
writeback activity. A 'wb_reason' enumeration has been
added to writeback.h, to enumerate the possible reasons.
The 'writeback_work_class' and tracepoint event class and
'writeback_queue_io' tracepoints are updated to include the
symbolic 'reason' in all trace events.
And the 'writeback_inodes_sbXXX' family of routines has had
a wb_stats parameter added to them, so callers can specify
why writeback is being started.
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Curt Wohlgemuth <curtw@google.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
diff --git a/fs/buffer.c b/fs/buffer.c
index 1a80b04..f5dcee6 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -285,7 +285,7 @@
struct zone *zone;
int nid;
- wakeup_flusher_threads(1024);
+ wakeup_flusher_threads(1024, WB_REASON_FREE_MORE_MEM);
yield();
for_each_online_node(nid) {