This is a note to let you know that I've just added the patch titled
hv_balloon: rate-limit "Unhandled message" warning
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
hv_balloon-rate-limit-unhandled-message-warning.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 154a5e84ddc71ea418246fd24205c175716b2160
Author: Anssi Hannula <anssi.hannula@xxxxxxxxxx>
Date: Tue Feb 22 16:14:00 2022 +0200
hv_balloon: rate-limit "Unhandled message" warning
[ Upstream commit 1d7286729aa616772be334eb908e11f527e1e291 ]
For a couple of times I have encountered a situation where
hv_balloon: Unhandled message: type: 12447
is being flooded over 1 million times per second with various values,
filling the log and consuming cycles, making debugging difficult.
Add rate limiting to the message.
Most other Hyper-V drivers already have similar rate limiting in their
message callbacks.
The cause of the floods in my case was probably fixed by 96d9d1fa5cd5
("Drivers: hv: balloon: account for vmbus packet header in
max_pkt_size").
Fixes: 9aa8b50b2b3d ("Drivers: hv: Add Hyper-V balloon driver")
Signed-off-by: Anssi Hannula <anssi.hannula@xxxxxxxxxx>
Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220222141400.98160-1-anssi.hannula@xxxxxxxxxx
Signed-off-by: Wei Liu <wei.liu@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index f2d05bff4245..439f99b8b5de 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -1563,7 +1563,7 @@ static void balloon_onchannelcallback(void *context)
break;
default:
- pr_warn("Unhandled message: type: %d\n", dm_hdr->type);
+ pr_warn_ratelimited("Unhandled message: type: %d\n", dm_hdr->type);
}
}
