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| author | Adam Li <adamli@os.amperecomputing.com> | 2024-02-26 02:24:52 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-05-02 16:29:24 +0200 |
| commit | 82810873acb43f0a41802f11e200363e40892c9f (patch) | |
| tree | e158d55a45ef13cd137cc138c580e6c95de21436 /Documentation | |
| parent | 0d14f104027e30720582448706c7d6b43065c851 (diff) | |
| download | linux-stable-82810873acb43f0a41802f11e200363e40892c9f.tar.gz linux-stable-82810873acb43f0a41802f11e200363e40892c9f.tar.bz2 linux-stable-82810873acb43f0a41802f11e200363e40892c9f.zip | |
net: make SK_MEMORY_PCPU_RESERV tunable
[ Upstream commit 12a686c2e761f1f1f6e6e2117a9ab9c6de2ac8a7 ]
This patch adds /proc/sys/net/core/mem_pcpu_rsv sysctl file,
to make SK_MEMORY_PCPU_RESERV tunable.
Commit 3cd3399dd7a8 ("net: implement per-cpu reserves for
memory_allocated") introduced per-cpu forward alloc cache:
"Implement a per-cpu cache of +1/-1 MB, to reduce number
of changes to sk->sk_prot->memory_allocated, which
would otherwise be cause of false sharing."
sk_prot->memory_allocated points to global atomic variable:
atomic_long_t tcp_memory_allocated ____cacheline_aligned_in_smp;
If increasing the per-cpu cache size from 1MB to e.g. 16MB,
changes to sk->sk_prot->memory_allocated can be further reduced.
Performance may be improved on system with many cores.
Signed-off-by: Adam Li <adamli@os.amperecomputing.com>
Reviewed-by: Christoph Lameter (Ampere) <cl@linux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 3584718cf2ec ("net: fix sk_memory_allocated_{add|sub} vs softirqs")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/admin-guide/sysctl/net.rst | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/admin-guide/sysctl/net.rst b/Documentation/admin-guide/sysctl/net.rst index 6394f5dc2303..e3894c928118 100644 --- a/Documentation/admin-guide/sysctl/net.rst +++ b/Documentation/admin-guide/sysctl/net.rst @@ -205,6 +205,11 @@ Will increase power usage. Default: 0 (off) +mem_pcpu_rsv +------------ + +Per-cpu reserved forward alloc cache size in page units. Default 1MB per CPU. + rmem_default ------------ |