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Re: [PATCH v2] net:Add sysctl_tcp_sg_max_skb_frags

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From	Eric Dumazet <eric.dumazet@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v2] net:Add sysctl_tcp_sg_max_skb_frags
Date	Wed, 27 Jan 2016 16:20:02 +0100
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On Wed, 2016-01-27 at 14:20 +0100, Hans Westgaard Ry wrote:
> Devices may have limits on the number of fragments in an skb they support.
> Current codebase uses a constant as maximum for number of fragments one
> skb can hold and use.
> When enabling scatter/gather and running traffic with many small messages
> the codebase uses the maximum number of fragments and may thereby violate
> the max for certain devices.
> The patch introduces a global variable as max number of fragments in
> scatter/gather.

Principle looks good, but we have to ask if other skb providers [1] will
add other sysctl, or if we could share a common one ?

If it is a common one, it should be /proc/sys/net/core/... instead
of /proc/sys/net/ipv4/tcp_....

Other providers include :

1) GRO stack
2) callers of sock_alloc_send_pskb(), alloc_skb_with_frags(),
sock_alloc_send_skb() ..

Thanks !

Thread

[PATCH v2] net:Add sysctl_tcp_sg_max_skb_frags Hans Westgaard Ry <hans.westgaard.ry@oracle.com> - 2016-01-27 14:30 +0100
  Re: [PATCH v2] net:Add sysctl_tcp_sg_max_skb_frags Eric Dumazet <eric.dumazet@gmail.com> - 2016-01-27 16:20 +0100
    Re: [PATCH v2] net:Add sysctl_tcp_sg_max_skb_frags Hannes Frederic Sowa <hannes@stressinduktion.org> - 2016-01-27 19:20 +0100
  Re: [PATCH v2] net:Add sysctl_tcp_sg_max_skb_frags David Miller <davem@davemloft.net> - 2016-01-27 21:20 +0100

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