tcp: Add memory barrier to tcp_push()
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Invalid
|
Undecided
|
Unassigned | ||
Focal |
Invalid
|
Undecided
|
Philip Cox | ||
Jammy |
Invalid
|
Undecided
|
Philip Cox | ||
Mantic |
Invalid
|
Undecided
|
Philip Cox | ||
linux-aws (Ubuntu) |
Invalid
|
Undecided
|
Unassigned | ||
Focal |
Fix Released
|
Undecided
|
Philip Cox | ||
Jammy |
Fix Released
|
Undecided
|
Philip Cox | ||
Mantic |
Fix Released
|
Undecided
|
Philip Cox |
Bug Description
Recently a patch has been accepted on the Linux Kernel regarding the TCP stack which fix an additional +40ms latency on ARM64 CPU architecture without impacting other CPU types.
More information can be find in here: https://<email address hidden>/
Would be possible to include the following patch as part of Linux image on the most recent and LTS maintained Ubuntu versions?
Patch:
```
---
net/ipv4/tcp.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index ff6838ca2e58.
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -722,6 +722,7 @@ void tcp_push(struct sock *sk, int flags, int mss_now,
if (!test_
NET_
set_
+ smp_mb_
}
/* It is possible TX completion already happened
* before we set TSQ_THROTTLED.
--
```
Changed in linux (Ubuntu Focal): | |
assignee: | nobody → Philip Cox (philcox) |
Changed in linux (Ubuntu Jammy): | |
assignee: | nobody → Philip Cox (philcox) |
Changed in linux (Ubuntu Mantic): | |
assignee: | nobody → Philip Cox (philcox) |
Changed in linux (Ubuntu Focal): | |
status: | New → In Progress |
Changed in linux (Ubuntu Jammy): | |
status: | New → In Progress |
Changed in linux (Ubuntu Mantic): | |
status: | New → In Progress |
Changed in linux (Ubuntu Focal): | |
status: | In Progress → Fix Committed |
Changed in linux (Ubuntu Jammy): | |
status: | In Progress → Fix Committed |
Changed in linux (Ubuntu Mantic): | |
status: | In Progress → Fix Committed |
tags: |
added: verification-passed-focal-linux-aws verification-passed-focal-linux-aws-5.15 verification-passed-jammy-linux-aws-fips verification-passed-mantic-linux-aws removed: verification-needed-focal-linux-aws verification-needed-focal-linux-aws-5.15 verification-needed-jammy-linux-aws-fips verification-needed-mantic-linux-aws |
tags: |
added: verification-done-focal-linux-aws verification-done-focal-linux-aws-5.15 verification-done-jammy-linux-aws-fips verification-done-mantic-linux-aws removed: verification-passed-focal-linux-aws verification-passed-focal-linux-aws-5.15 verification-passed-jammy-linux-aws-fips verification-passed-mantic-linux-aws |
This bug is awaiting verification that the linux-aws/ 5.4.0-1122. 132 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification- needed- focal-linux- aws' to 'verification- done-focal- linux-aws' . If the problem still exists, change the tag 'verification- needed- focal-linux- aws' to 'verification- failed- focal-linux- aws'.
If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.
See https:/ /wiki.ubuntu. com/Testing/ EnableProposed for documentation how to enable and use -proposed. Thank you!