Re: [PATCH net-next] net: set net.core.rmem_max and net.core.wmem_max to 4 MB

Neal Cardwell
2025-08-19T18:17:40Z

On Tue, Aug 19, 2025 at 1:43 PM Eric Dumazet <edumazet@google.com> wrote:
>
> SO_RCVBUF and SO_SNDBUF have limited range today, unless
> distros or system admins change rmem_max and wmem_max.
>
> Even iproute2 uses 1 MB SO_RCVBUF which is capped by
> the kernel.
>
> Decouple [rw]mem_max and [rw]mem_default and increase
> [rw]mem_max to 4 MB.
>
> Before:
>
> $ sysctl net.core.rmem_default net.core.rmem_max net.core.wmem_default net.core.wmem_max
> net.core.rmem_default = 212992
> net.core.rmem_max = 212992
> net.core.wmem_default = 212992
> net.core.wmem_max = 212992
>
> After:
>
> $ sysctl net.core.rmem_default net.core.rmem_max net.core.wmem_default net.core.wmem_max
> net.core.rmem_default = 212992
> net.core.rmem_max = 4194304
> net.core.wmem_default = 212992
> net.core.wmem_max = 4194304
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---

Great! Thanks, Eric!

Reviewed-by: Neal Cardwell <ncardwell@google.com>

neal