On Fri, Jul 29, 2016 at 9:21 AM, Neal Cardwell <ncardw...@google.com> wrote:
>
> On Thu, Jul 28, 2016 at 11:11 PM, Soheil Hassas Yeganeh
> <soheil.k...@gmail.com> wrote:
> >
> > From: Soheil Hassas Yeganeh <soh...@google.com>
> >
> > tcp_select_initial_window() intends to advertise a window
> > scaling for the maximum possible window size. To do so,
> > it considers the maximum of net.ipv4.tcp_rmem[2] and
> > net.core.rmem_max as the only possible upper-bounds.
> > However, users with CAP_NET_ADMIN can use SO_RCVBUFFORCE
> > to set the socket's receive buffer size to values
> > larger than net.ipv4.tcp_rmem[2] and net.core.rmem_max.
> > Thus, SO_RCVBUFFORCE is effectively ignored by
> > tcp_select_initial_window().
> >
> > To fix this, consider the maximum of net.ipv4.tcp_rmem[2],
> > net.core.rmem_max and socket's initial buffer space.
> >
> > This part of the code does not have git history and as a
> > result this patch does not have a `Fixes:` tag.
> >
> > Signed-off-by: Soheil Hassas Yeganeh <soh...@google.com>
> > Suggested-by: Neal Cardwell <ncardw...@google.com>
>
> I think it makes sense to tag this commit with:
>
> Fixes: b0573dea1fb3 ("[NET]: Introduce SO_{SND,RCV}BUFFORCE socket options")Thanks for noting the SHA1. I'll send a v2. Thanks, Soheil > ... because that's the moment at which this line of code started > failing to achieve its stated objective of setting the window scaling > factor based on the max possible window. > > And having a Fixes tag would help maintainers figure out that the > patch makes sense to apply to kernels after that commit. > > thanks, > neal
