Hi, Tejun

在 2022/08/24 2:34, Tejun Heo 写道:

On Tue, Aug 23, 2022 at 09:38:10AM +0800, Yu Kuai wrote:

quoted

From: Yu Kuai <redacted>

Now that throtl_dequeue_tg() is called when the last bio is dispatched,
there is no need to check the flag THROTL_TG_PENDING, since it's ensured
to be set when bio is throttled.

There are no functional changes.

Signed-off-by: Yu Kuai <redacted>
---
  block/blk-throttle.c | 11 ++++-------
  1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 47142a1dd102..e47506a8ef47 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c

@@ -570,14 +570,11 @@ static void throtl_enqueue_tg(struct throtl_grp *tg)
  
  static void throtl_dequeue_tg(struct throtl_grp *tg)
  {
-	if (tg->flags & THROTL_TG_PENDING) {
-		struct throtl_service_queue *parent_sq =
-			tg->service_queue.parent_sq;
+	struct throtl_service_queue *parent_sq = tg->service_queue.parent_sq;
  
-		throtl_rb_erase(&tg->rb_node, parent_sq);
-		--parent_sq->nr_pending;
-		tg->flags &= ~THROTL_TG_PENDING;
-	}
+	throtl_rb_erase(&tg->rb_node, parent_sq);
+	--parent_sq->nr_pending;
+	tg->flags &= ~THROTL_TG_PENDING;

Yeah, I don't know about this one. This breaks the symmetry with
throtl_enqueue_tg() and it's a bit odd that we aren't at least
WARN_ON_ONCE() on the flag given what the flag tracks. If you want to do
this, I think the prev approach of just removing the flag is better as that
was symmetric at least.

Yes, you are right, thanks for the advice. Since now it's a bit
ambivalent, we might as well just remove this patch?

Thanks,
Kuai

Thanks.