[SRU][m/n][PATCH 0/2] arm64: TCP memory leak, slow network

[Philip Cox]

BugLink: BugLink: https://bugs.launchpad.net/bugs/2045560


SRU Justification:

[Impact]
There is a slow performance regression in the arm64 TCP code path. It appears to slowly leak memory as well.

This was caused to do amd64 and arm64 behaving differently in the codepaths and being IRQ safe.

The regression was introduced in kernel v6.0, and the fix is in v6.9.


[Fix]
The fix is to bring the arm64 behavior inline with the arm64 behavior, and remove the preempt_disable()/preempt_enable() pairs.

There are two patches required from the 6.8.y stable branch for this fix.   The two patches from the stable 6.8.y branch are:
e830c804e267     net: make SK_MEMORY_PCPU_RESERV tunable 
d2fa3493811ec     net: fix sk_memory_allocated_{add|sub} vs softirqs

[Test Plan]
I have tested this patch, as has AWS.

[Where problems could occur]
Due to the differences of how irq preemption is being handled, future code may conflict with the new helpers introduced.


--


Adam Li (1):
  net: make SK_MEMORY_PCPU_RESERV tunable

Eric Dumazet (1):
  net: fix sk_memory_allocated_{add|sub} vs softirqs

 Documentation/admin-guide/sysctl/net.rst |  5 +++
 include/net/sock.h                       | 39 +++++++++++++-----------
 net/core/sock.c                          |  1 +
 net/core/sysctl_net_core.c               |  9 ++++++
 4 files changed, 36 insertions(+), 18 deletions(-)

-- 
2.34.1