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Eric Dumazet ec00ed472b tcp: avoid premature drops in tcp_add_backlog()
While testing TCP performance with latest trees,
I saw suspect SOCKET_BACKLOG drops.

tcp_add_backlog() computes its limit with :

    limit = (u32)READ_ONCE(sk->sk_rcvbuf) +
            (u32)(READ_ONCE(sk->sk_sndbuf) >> 1);
    limit += 64 * 1024;

This does not take into account that sk->sk_backlog.len
is reset only at the very end of __release_sock().

Both sk->sk_backlog.len and sk->sk_rmem_alloc could reach
sk_rcvbuf in normal conditions.

We should double sk->sk_rcvbuf contribution in the formula
to absorb bubbles in the backlog, which happen more often
for very fast flows.

This change maintains decent protection against abuses.

Fixes: c377411f24 ("net: sk_add_backlog() take rmem_alloc into account")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240423125620.3309458-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-25 12:15:02 -07:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-04-18 13:12:24 -07:00
block block-6.9-20240412 2024-04-12 10:22:33 -07:00
certs This update includes the following changes: 2023-11-02 16:15:30 -10:00
crypto net: add sk_wake_async_rcu() helper 2024-03-29 15:03:11 -07:00
Documentation Merge branch '100GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/next-queue 2024-04-24 20:05:31 -07:00
drivers wireless-next patches for v6.10 2024-04-25 11:49:35 -07:00
fs Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-04-18 13:12:24 -07:00
include wireless-next patches for v6.10 2024-04-25 11:49:35 -07:00
init fs/proc: Skip bootloader comment if no embedded kernel parameters 2024-04-09 23:36:18 +09:00
io_uring net: extend ubuf_info callback to ops structure 2024-04-22 16:21:35 -07:00
ipc sysctl: treewide: constify ctl_table_header::ctl_table_arg 2024-04-22 08:56:31 +01:00
kernel sysctl: treewide: constify ctl_table_header::ctl_table_arg 2024-04-22 08:56:31 +01:00
lib net: dqs: make struct dql more cache efficient 2024-04-15 11:19:53 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm x86/mm/pat: fix VM_PAT handling in COW mappings 2024-04-05 11:21:31 -07:00
net tcp: avoid premature drops in tcp_add_backlog() 2024-04-25 12:15:02 -07:00
rust Kbuild updates for v6.9 2024-03-21 14:41:00 -07:00
samples Tracing updates for 6.9: 2024-03-18 15:11:44 -07:00
scripts Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-04-11 14:23:47 -07:00
security security: Place security_path_post_mknod() where the original IMA call was 2024-04-03 10:21:32 -07:00
sound ASoC: Fixes for v6.9 2024-04-05 08:48:12 +02:00
tools tools: testing: selftests: prefer TEST_PROGS for conntrack_dump_flush 2024-04-25 07:36:51 -07:00
usr Kbuild updates for v6.8 2024-01-18 17:57:07 -08:00
virt KVM Xen and pfncache changes for 6.9: 2024-03-11 10:42:55 -04:00
.clang-format clang-format: Update with v6.7-rc4's for_each macro list 2023-12-08 23:54:38 +01:00
.cocciconfig
.editorconfig Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: create a list of all built DTB files 2024-02-19 18:20:39 +09:00
.mailmap MAINTAINERS: change vmware.com addresses to broadcom.com 2024-04-05 11:21:31 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING
CREDITS MAINTAINERS: Drop Gustavo Pimentel as PCI DWC Maintainer 2024-03-27 13:41:02 -05:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: Add myself to pse networking maintainer 2024-04-18 18:27:02 -07:00
Makefile Linux 6.9-rc4 2024-04-14 13:38:39 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

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 reStructuredText 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.