From: Kent Overstreet <kent.overstreet@linux.dev>
Date: Wed, 22 Jan 2025 19:38:59 +0000 (-0500)
Subject: bcachefs: Separate running/runnable in wp stats
X-Git-Tag: v6.15-rc1~146^2~173
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=999cc1bb6888c484fbd5dd9c8397c200772bd243;p=thirdparty%2Fkernel%2Flinux.git

bcachefs: Separate running/runnable in wp stats

We've got per-writepoint statistics to see how well the writepoint index
update threads are pipelining; this separates running vs. runnable so we
can see at a glance if they're blocking.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
---

diff --git a/fs/bcachefs/alloc_types.h b/fs/bcachefs/alloc_types.h
index 4aa8ee026cb84..8f79f46c2a781 100644
--- a/fs/bcachefs/alloc_types.h
+++ b/fs/bcachefs/alloc_types.h
@@ -90,6 +90,7 @@ struct dev_stripe_state {
 	x(stopped)			\
 	x(waiting_io)			\
 	x(waiting_work)			\
+	x(runnable)			\
 	x(running)
 
 enum write_point_state {
@@ -125,6 +126,7 @@ struct write_point {
 		enum write_point_state	state;
 		u64			last_state_change;
 		u64			time[WRITE_POINT_STATE_NR];
+		u64			last_runtime;
 	} __aligned(SMP_CACHE_BYTES);
 };
 
diff --git a/fs/bcachefs/io_write.c b/fs/bcachefs/io_write.c
index 970f3f0959a42..a903f39caa3e8 100644
--- a/fs/bcachefs/io_write.c
+++ b/fs/bcachefs/io_write.c
@@ -587,7 +587,15 @@ err:
 static inline void __wp_update_state(struct write_point *wp, enum write_point_state state)
 {
 	if (state != wp->state) {
+		struct task_struct *p = current;
 		u64 now = ktime_get_ns();
+		u64 runtime = p->se.sum_exec_runtime +
+			(now - p->se.exec_start);
+
+		if (state == WRITE_POINT_runnable)
+			wp->last_runtime = runtime;
+		else if (wp->state == WRITE_POINT_runnable)
+			wp->time[WRITE_POINT_running] += runtime - wp->last_runtime;
 
 		if (wp->last_state_change &&
 		    time_after64(now, wp->last_state_change))
@@ -601,7 +609,7 @@ static inline void wp_update_state(struct write_point *wp, bool running)
 {
 	enum write_point_state state;
 
-	state = running			 ? WRITE_POINT_running :
+	state = running			 ? WRITE_POINT_runnable:
 		!list_empty(&wp->writes) ? WRITE_POINT_waiting_io
 					 : WRITE_POINT_stopped;