Linux mainline fork with MSM8998 patches | https://mainline.space | Currently supported devices:
OnePlus 5/5T, Xiaomi Mi 6, F(x)tec Pro¹ (2019 QX1000 model) & Sony Xperia XZ Premium (UNTESTED!)
240bfd134c
tcp_grow_window() is using skb->len/skb->truesize to increase tp->rcv_ssthresh which has a direct impact on advertized window sizes. We added TCP coalescing in linux-3.4 & linux-3.5: Instead of storing skbs with one or two MSS in receive queue (or OFO queue), we try to append segments together to reduce memory overhead. High performance network drivers tend to cook skb with 3 parts : 1) sk_buff structure (256 bytes) 2) skb->head contains room to copy headers as needed, and skb_shared_info 3) page fragment(s) containing the ~1514 bytes frame (or more depending on MTU) Once coalesced into a previous skb, 1) and 2) are freed. We can therefore tweak the way we compute len/truesize ratio knowing that skb->truesize is inflated by 1) and 2) soon to be freed. This is done only for in-order skb, or skb coalesced into OFO queue. The result is that low rate flows no longer pay the memory price of having low GRO aggregation factor. Same result for drivers not using GRO. This is critical to allow a big enough receiver window, typically tcp_rmem[2] / 2. We have been using this at Google for about 5 years, it is due time to make it upstream. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Soheil Hassas Yeganeh <soheil@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Yuchung Cheng <ycheng@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@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.