mainlining shenanigans
cff04e2da3
Current 1ms clock feeds ca->round_start, ca->delay_min, ca->last_ack. This is quite problematic for data-center flows, where delay_min is way below 1 ms. This means Hystart Train detection triggers every time jiffies value is updated, since "((s32)(now - ca->round_start) > ca->delay_min >> 4)" expression becomes true. This kind of random behavior can be solved by reusing the existing usec timestamp that TCP keeps in tp->tcp_mstamp Note that a followup patch will tweak things a bit, because during slow start, GRO aggregation on receivers naturally increases the RTT as TSO packets gradually come to ~64KB size. To recap, right after this patch CUBIC Hystart train detection is more aggressive, since short RTT flows might exit slow start at cwnd = 20, instead of being possibly unbounded. Following patch will address this problem. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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.
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.