c36207bd87
In tcp_select_initial_window(), we only set rcv_wnd to tcp_default_init_rwnd() if current mss > (1 << wscale). Otherwise, rcv_wnd is kept at the full receive space of the socket which is a value way larger than tcp_default_init_rwnd(). With larger initial rcv_wnd value, receive buffer autotuning logic takes longer to kick in and increase the receive buffer. In a TCP throughput test where receiver has rmem[2] set to 125MB (wscale is 11), we see the connection gets recvbuf limited at the beginning of the connection and gets less throughput overall. Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.