No description
  • C 98.2%
  • Assembly 1%
  • Makefile 0.3%
  • Shell 0.2%
  • Python 0.1%
Find a file
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Neal Cardwell 2791d64e66 tcp: fix quick-ack counting to count actual ACKs of new data
[ Upstream commit 059217c18be6757b95bfd77ba53fb50b48b8a816 ]

This commit fixes quick-ack counting so that it only considers that a
quick-ack has been provided if we are sending an ACK that newly
acknowledges data.

The code was erroneously using the number of data segments in outgoing
skbs when deciding how many quick-ack credits to remove. This logic
does not make sense, and could cause poor performance in
request-response workloads, like RPC traffic, where requests or
responses can be multi-segment skbs.

When a TCP connection decides to send N quick-acks, that is to
accelerate the cwnd growth of the congestion control module
controlling the remote endpoint of the TCP connection. That quick-ack
decision is purely about the incoming data and outgoing ACKs. It has
nothing to do with the outgoing data or the size of outgoing data.

And in particular, an ACK only serves the intended purpose of allowing
the remote congestion control to grow the congestion window quickly if
the ACK is ACKing or SACKing new data.

The fix is simple: only count packets as serving the goal of the
quickack mechanism if they are ACKing/SACKing new data. We can tell
whether this is the case by checking inet_csk_ack_scheduled(), since
we schedule an ACK exactly when we are ACKing/SACKing new data.

Fixes: fc6415bcb0 ("[TCP]: Fix quick-ack decrementing with TSO.")
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Yuchung Cheng <ycheng@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20231001151239.1866845-1-ncardwell.sw@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-10 21:46:44 +02:00
arch powerpc/watchpoints: Annotate atomic context in more places 2023-10-10 21:46:40 +02:00
block block/partition: fix signedness issue for Amiga partitions 2023-07-27 08:37:29 +02:00
certs
crypto X.509: if signature is unsupported skip validation 2023-09-23 10:59:55 +02:00
Documentation perf/smmuv3: Enable HiSilicon Erratum 162001900 quirk for HIP08/09 2023-09-23 11:00:03 +02:00
drivers net: stmmac: dwmac-stm32: fix resume on STM32 MCU 2023-10-10 21:46:44 +02:00
fs NFSv4: Fix a nfs4_state_manager() race 2023-10-10 21:46:44 +02:00
include tcp: fix quick-ack counting to count actual ACKs of new data 2023-10-10 21:46:44 +02:00
init x86/mm: Initialize text poking earlier 2023-08-08 19:56:36 +02:00
ipc
kernel ring-buffer: Update "shortest_full" in polling 2023-10-10 21:46:41 +02:00
lib kobject: Add sanity check for kset->kobj.ktype in kset_register() 2023-09-23 11:00:05 +02:00
LICENSES
mm tmpfs: verify {g,u}id mount options correctly 2023-09-23 10:59:40 +02:00
net tcp: fix quick-ack counting to count actual ACKs of new data 2023-10-10 21:46:44 +02:00
samples samples/bpf: Fix buffer overflow in tcp_basertt 2023-07-27 08:37:07 +02:00
scripts modpost: add missing else to the "of" check 2023-10-10 21:46:44 +02:00
security ima: Finish deprecation of IMA_TRUSTED_KEYRING Kconfig 2023-10-10 21:46:43 +02:00
sound ALSA: hda: Disable power save for solving pop issue on Lenovo ThinkCentre M70q 2023-10-10 21:46:41 +02:00
tools bpf: Clarify error expectations from bpf_clone_redirect 2023-10-10 21:46:40 +02:00
usr
virt KVM: Destroy target device if coalesced MMIO unregistration fails 2023-03-11 16:44:01 +01:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS iio: stx104: Move to addac subdirectory 2023-08-30 16:27:12 +02:00
Makefile Linux 5.4.257 2023-09-23 11:00:07 +02:00
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.