From 3a8e9ac89e6a5106cfb6b85d4c9cf9bfa3519bc7 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 29 Aug 2019 15:47:19 -0700 Subject: writeback: add tracepoints for cgroup foreign writebacks cgroup foreign inode handling has quite a bit of heuristics and internal states which sometimes makes it difficult to understand what's going on. Add tracepoints to improve visibility. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- fs/fs-writeback.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'fs') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 658dc16c9e6d..8aaa7eec7b74 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -389,6 +389,8 @@ static void inode_switch_wbs_work_fn(struct work_struct *work) if (unlikely(inode->i_state & I_FREEING)) goto skip_switch; + trace_inode_switch_wbs(inode, old_wb, new_wb); + /* * Count and transfer stats. Note that PAGECACHE_TAG_DIRTY points * to possibly dirty pages while PAGECACHE_TAG_WRITEBACK points to @@ -673,6 +675,9 @@ void wbc_detach_inode(struct writeback_control *wbc) if (wbc->wb_id != max_id) history |= (1U << slots) - 1; + if (history) + trace_inode_foreign_history(inode, wbc, history); + /* * Switch if the current wb isn't the consistent winner. * If there are multiple closely competing dirtiers, the -- cgit