From 0cee64c547e3c9cda646af3e075a64f445ee8148 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Fri, 12 Sep 2025 12:38:38 +0200 Subject: writeback: Add tracepoint to track pending inode switches Add trace_inode_switch_wbs_queue tracepoint to allow insight into how many inodes are queued to switch their bdi_writeback structure. Acked-by: Tejun Heo Signed-off-by: Jan Kara Signed-off-by: Christian Brauner --- include/trace/events/writeback.h | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'include/trace') diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h index 1e23919c0da9..c08aff044e80 100644 --- a/include/trace/events/writeback.h +++ b/include/trace/events/writeback.h @@ -213,6 +213,35 @@ TRACE_EVENT(inode_foreign_history, ) ); +TRACE_EVENT(inode_switch_wbs_queue, + + TP_PROTO(struct bdi_writeback *old_wb, struct bdi_writeback *new_wb, + unsigned int count), + + TP_ARGS(old_wb, new_wb, count), + + TP_STRUCT__entry( + __array(char, name, 32) + __field(ino_t, old_cgroup_ino) + __field(ino_t, new_cgroup_ino) + __field(unsigned int, count) + ), + + TP_fast_assign( + strscpy_pad(__entry->name, bdi_dev_name(old_wb->bdi), 32); + __entry->old_cgroup_ino = __trace_wb_assign_cgroup(old_wb); + __entry->new_cgroup_ino = __trace_wb_assign_cgroup(new_wb); + __entry->count = count; + ), + + TP_printk("bdi %s: old_cgroup_ino=%lu new_cgroup_ino=%lu count=%u", + __entry->name, + (unsigned long)__entry->old_cgroup_ino, + (unsigned long)__entry->new_cgroup_ino, + __entry->count + ) +); + TRACE_EVENT(inode_switch_wbs, TP_PROTO(struct inode *inode, struct bdi_writeback *old_wb, -- cgit v1.2.3