diff options
| author | Kuniyuki Iwashima <kuniyu@google.com> | 2025-10-15 02:54:56 +0300 |
|---|---|---|
| committer | Martin KaFai Lau <martin.lau@kernel.org> | 2025-10-16 22:04:47 +0300 |
| commit | b46ab63181ff973ddce44ebc9ac24b269d42f481 (patch) | |
| tree | f0dd1c7eb51f2db2cb3fdc9f33ed0b2306957c93 /include | |
| parent | 7c268eaeec6388b7bee36aef3fb5e62c9222ad3b (diff) | |
| download | linux-b46ab63181ff973ddce44ebc9ac24b269d42f481.tar.xz | |
net: Introduce net.core.bypass_prot_mem sysctl.
If a socket has sk->sk_bypass_prot_mem flagged, the socket opts out
of the global protocol memory accounting.
Let's control the flag by a new sysctl knob.
The flag is written once during socket(2) and is inherited to child
sockets.
Tested with a script that creates local socket pairs and send()s a
bunch of data without recv()ing.
Setup:
# mkdir /sys/fs/cgroup/test
# echo $$ >> /sys/fs/cgroup/test/cgroup.procs
# sysctl -q net.ipv4.tcp_mem="1000 1000 1000"
# ulimit -n 524288
Without net.core.bypass_prot_mem, charged to tcp_mem & memcg
# python3 pressure.py &
# cat /sys/fs/cgroup/test/memory.stat | grep sock
sock 22642688 <-------------------------------------- charged to memcg
# cat /proc/net/sockstat| grep TCP
TCP: inuse 2006 orphan 0 tw 0 alloc 2008 mem 5376 <-- charged to tcp_mem
# ss -tn | head -n 5
State Recv-Q Send-Q Local Address:Port Peer Address:Port
ESTAB 2000 0 127.0.0.1:34479 127.0.0.1:53188
ESTAB 2000 0 127.0.0.1:34479 127.0.0.1:49972
ESTAB 2000 0 127.0.0.1:34479 127.0.0.1:53868
ESTAB 2000 0 127.0.0.1:34479 127.0.0.1:53554
# nstat | grep Pressure || echo no pressure
TcpExtTCPMemoryPressures 1 0.0
With net.core.bypass_prot_mem=1, charged to memcg only:
# sysctl -q net.core.bypass_prot_mem=1
# python3 pressure.py &
# cat /sys/fs/cgroup/test/memory.stat | grep sock
sock 2757468160 <------------------------------------ charged to memcg
# cat /proc/net/sockstat | grep TCP
TCP: inuse 2006 orphan 0 tw 0 alloc 2008 mem 0 <- NOT charged to tcp_mem
# ss -tn | head -n 5
State Recv-Q Send-Q Local Address:Port Peer Address:Port
ESTAB 111000 0 127.0.0.1:36019 127.0.0.1:49026
ESTAB 110000 0 127.0.0.1:36019 127.0.0.1:45630
ESTAB 110000 0 127.0.0.1:36019 127.0.0.1:44870
ESTAB 111000 0 127.0.0.1:36019 127.0.0.1:45274
# nstat | grep Pressure || echo no pressure
no pressure
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Link: https://patch.msgid.link/20251014235604.3057003-4-kuniyu@google.com
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/netns/core.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/net/netns/core.h b/include/net/netns/core.h index cb9c3e4cd738..9ef3d70e5e9c 100644 --- a/include/net/netns/core.h +++ b/include/net/netns/core.h @@ -17,6 +17,7 @@ struct netns_core { int sysctl_optmem_max; u8 sysctl_txrehash; u8 sysctl_tstamp_allow_data; + u8 sysctl_bypass_prot_mem; #ifdef CONFIG_PROC_FS struct prot_inuse __percpu *prot_inuse; |