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| author | Eric Dumazet <edumazet@google.com> | 2023-12-14 10:48:59 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2023-12-15 11:01:26 +0000 |
| commit | 4944566706b27918ca15eda913889db296792415 (patch) | |
| tree | 1e160c6b6ecaa5d209620e62a1a9f6a562de37aa | |
| parent | e16064c9af7fe5a2220f7ad5f9be6fd7516e427c (diff) | |
| download | linux-stable-4944566706b27918ca15eda913889db296792415.tar.gz linux-stable-4944566706b27918ca15eda913889db296792415.tar.bz2 linux-stable-4944566706b27918ca15eda913889db296792415.zip | |
net: increase optmem_max default value
For many years, /proc/sys/net/core/optmem_max default value
on a 64bit kernel has been 20 KB.
Regular usage of TCP tx zerocopy needs a bit more.
Google has used 128KB as the default value for 7 years without
any problem.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | Documentation/admin-guide/sysctl/net.rst | 5 | ||||
| -rw-r--r-- | net/core/sock.c | 6 |
2 files changed, 8 insertions, 3 deletions
diff --git a/Documentation/admin-guide/sysctl/net.rst b/Documentation/admin-guide/sysctl/net.rst index c7525942f12c..396091651955 100644 --- a/Documentation/admin-guide/sysctl/net.rst +++ b/Documentation/admin-guide/sysctl/net.rst @@ -345,7 +345,10 @@ optmem_max ---------- Maximum ancillary buffer size allowed per socket. Ancillary data is a sequence -of struct cmsghdr structures with appended data. +of struct cmsghdr structures with appended data. TCP tx zerocopy also uses +optmem_max as a limit for its internal structures. + +Default : 128 KB fb_tunnels_only_for_init_net ---------------------------- diff --git a/net/core/sock.c b/net/core/sock.c index fef349dd72fa..08ecdc68d2df 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -283,8 +283,10 @@ EXPORT_SYMBOL(sysctl_rmem_max); __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX; __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX; -/* Maximal space eaten by iovec or ancillary data plus some space */ -int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512); +/* Limits per socket sk_omem_alloc usage. + * TCP zerocopy regular usage needs 128 KB. + */ +int sysctl_optmem_max __read_mostly = 128 * 1024; EXPORT_SYMBOL(sysctl_optmem_max); int sysctl_tstamp_allow_data __read_mostly = 1; |