<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/net/core/net_namespace.c, branch v6.19.11</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v6.19.11</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v6.19.11'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2025-12-04T01:24:33+00:00</updated>
<entry>
<title>Merge tag 'net-next-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next</title>
<updated>2025-12-04T01:24:33+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-12-04T01:24:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=8f7aa3d3c7323f4ca2768a9e74ebbe359c4f8f88'/>
<id>urn:sha1:8f7aa3d3c7323f4ca2768a9e74ebbe359c4f8f88</id>
<content type='text'>
Pull networking updates from Jakub Kicinski:
 "Core &amp; protocols:

   - Replace busylock at the Tx queuing layer with a lockless list.

     Resulting in a 300% (4x) improvement on heavy TX workloads, sending
     twice the number of packets per second, for half the cpu cycles.

   - Allow constantly busy flows to migrate to a more suitable CPU/NIC
     queue.

     Normally we perform queue re-selection when flow comes out of idle,
     but under extreme circumstances the flows may be constantly busy.

     Add sysctl to allow periodic rehashing even if it'd risk packet
     reordering.

   - Optimize the NAPI skb cache, make it larger, use it in more paths.

   - Attempt returning Tx skbs to the originating CPU (like we already
     did for Rx skbs).

   - Various data structure layout and prefetch optimizations from Eric.

   - Remove ktime_get() from the recvmsg() fast path, ktime_get() is
     sadly quite expensive on recent AMD machines.

   - Extend threaded NAPI polling to allow the kthread busy poll for
     packets.

   - Make MPTCP use Rx backlog processing. This lowers the lock
     pressure, improving the Rx performance.

   - Support memcg accounting of MPTCP socket memory.

   - Allow admin to opt sockets out of global protocol memory accounting
     (using a sysctl or BPF-based policy). The global limits are a poor
     fit for modern container workloads, where limits are imposed using
     cgroups.

   - Improve heuristics for when to kick off AF_UNIX garbage collection.

   - Allow users to control TCP SACK compression, and default to 33% of
     RTT.

   - Add tcp_rcvbuf_low_rtt sysctl to let datacenter users avoid
     unnecessarily aggressive rcvbuf growth and overshot when the
     connection RTT is low.

   - Preserve skb metadata space across skb_push / skb_pull operations.

   - Support for IPIP encapsulation in the nftables flowtable offload.

   - Support appending IP interface information to ICMP messages (RFC
     5837).

   - Support setting max record size in TLS (RFC 8449).

   - Remove taking rtnl_lock from RTM_GETNEIGHTBL and RTM_SETNEIGHTBL.

   - Use a dedicated lock (and RCU) in MPLS, instead of rtnl_lock.

   - Let users configure the number of write buffers in SMC.

   - Add new struct sockaddr_unsized for sockaddr of unknown length,
     from Kees.

   - Some conversions away from the crypto_ahash API, from Eric Biggers.

   - Some preparations for slimming down struct page.

   - YAML Netlink protocol spec for WireGuard.

   - Add a tool on top of YAML Netlink specs/lib for reporting commonly
     computed derived statistics and summarized system state.

  Driver API:

   - Add CAN XL support to the CAN Netlink interface.

   - Add uAPI for reporting PHY Mean Square Error (MSE) diagnostics, as
     defined by the OPEN Alliance's "Advanced diagnostic features for
     100BASE-T1 automotive Ethernet PHYs" specification.

   - Add DPLL phase-adjust-gran pin attribute (and implement it in
     zl3073x).

   - Refactor xfrm_input lock to reduce contention when NIC offloads
     IPsec and performs RSS.

   - Add info to devlink params whether the current setting is the
     default or a user override. Allow resetting back to default.

   - Add standard device stats for PSP crypto offload.

   - Leverage DSA frame broadcast to implement simple HSR frame
     duplication for a lot of switches without dedicated HSR offload.

   - Add uAPI defines for 1.6Tbps link modes.

  Device drivers:

   - Add Motorcomm YT921x gigabit Ethernet switch support.

   - Add MUCSE driver for N500/N210 1GbE NIC series.

   - Convert drivers to support dedicated ops for timestamping control,
     and away from the direct IOCTL handling. While at it support GET
     operations for PHY timestamping.

   - Add (and convert most drivers to) a dedicated ethtool callback for
     reading the Rx ring count.

   - Significant refactoring efforts in the STMMAC driver, which
     supports Synopsys turn-key MAC IP integrated into a ton of SoCs.

   - Ethernet high-speed NICs:
      - Broadcom (bnxt):
         - support PPS in/out on all pins
      - Intel (100G, ice, idpf):
         - ice: implement standard ethtool and timestamping stats
         - i40e: support setting the max number of MAC addresses per VF
         - iavf: support RSS of GTP tunnels for 5G and LTE deployments
      - nVidia/Mellanox (mlx5):
         - reduce downtime on interface reconfiguration
         - disable being an XDP redirect target by default (same as
           other drivers) to avoid wasting resources if feature is
           unused
      - Meta (fbnic):
         - add support for Linux-managed PCS on 25G, 50G, and 100G links
      - Wangxun:
         - support Rx descriptor merge, and Tx head writeback
         - support Rx coalescing offload
         - support 25G SPF and 40G QSFP modules

   - Ethernet virtual:
      - Google (gve):
         - allow ethtool to configure rx_buf_len
         - implement XDP HW RX Timestamping support for DQ descriptor
           format
      - Microsoft vNIC (mana):
         - support HW link state events
         - handle hardware recovery events when probing the device

   - Ethernet NICs consumer, and embedded:
      - usbnet: add support for Byte Queue Limits (BQL)
      - AMD (amd-xgbe):
         - add device selftests
      - NXP (enetc):
         - add i.MX94 support
      - Broadcom integrated MACs (bcmgenet, bcmasp):
         - bcmasp: add support for PHY-based Wake-on-LAN
      - Broadcom switches (b53):
         - support port isolation
         - support BCM5389/97/98 and BCM63XX ARL formats
      - Lantiq/MaxLinear switches:
         - support bridge FDB entries on the CPU port
         - use regmap for register access
         - allow user to enable/disable learning
         - support Energy Efficient Ethernet
         - support configuring RMII clock delays
         - add tagging driver for MaxLinear GSW1xx switches
      - Synopsys (stmmac):
         - support using the HW clock in free running mode
         - add Eswin EIC7700 support
         - add Rockchip RK3506 support
         - add Altera Agilex5 support
      - Cadence (macb):
         - cleanup and consolidate descriptor and DMA address handling
         - add EyeQ5 support
      - TI:
         - icssg-prueth: support AF_XDP
      - Airoha access points:
         - add missing Ethernet stats and link state callback
         - add AN7583 support
         - support out-of-order Tx completion processing
      - Power over Ethernet:
         - pd692x0: preserve PSE configuration across reboots
         - add support for TPS23881B devices

   - Ethernet PHYs:
      - Open Alliance OATC14 10BASE-T1S PHY cable diagnostic support
      - Support 50G SerDes and 100G interfaces in Linux-managed PHYs
      - micrel:
         - support for non PTP SKUs of lan8814
         - enable in-band auto-negotiation on lan8814
      - realtek:
         - cable testing support on RTL8224
         - interrupt support on RTL8221B
      - motorcomm: support for PHY LEDs on YT853
      - microchip: support for LAN867X Rev.D0 PHYs w/ SQI and cable diag
      - mscc: support for PHY LED control

   - CAN drivers:
      - m_can: add support for optional reset and system wake up
      - remove can_change_mtu() obsoleted by core handling
      - mcp251xfd: support GPIO controller functionality

   - Bluetooth:
      - add initial support for PASTa

   - WiFi:
      - split ieee80211.h file, it's way too big
      - improvements in VHT radiotap reporting, S1G, Channel Switch
        Announcement handling, rate tracking in mesh networks
      - improve multi-radio monitor mode support, and add a cfg80211
        debugfs interface for it
      - HT action frame handling on 6 GHz
      - initial chanctx work towards NAN
      - MU-MIMO sniffer improvements

   - WiFi drivers:
      - RealTek (rtw89):
         - support USB devices RTL8852AU and RTL8852CU
         - initial work for RTL8922DE
         - improved injection support
      - Intel:
         - iwlwifi: new sniffer API support
      - MediaTek (mt76):
         - WED support for &gt;32-bit DMA
         - airoha NPU support
         - regdomain improvements
         - continued WiFi7/MLO work
      - Qualcomm/Atheros:
         - ath10k: factory test support
         - ath11k: TX power insertion support
         - ath12k: BSS color change support
         - ath12k: statistics improvements
      - brcmfmac: Acer A1 840 tablet quirk
      - rtl8xxxu: 40 MHz connection fixes/support"

* tag 'net-next-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1381 commits)
  net: page_pool: sanitise allocation order
  net: page pool: xa init with destroy on pp init
  net/mlx5e: Support XDP target xmit with dummy program
  net/mlx5e: Update XDP features in switch channels
  selftests/tc-testing: Test CAKE scheduler when enqueue drops packets
  net/sched: sch_cake: Fix incorrect qlen reduction in cake_drop
  wireguard: netlink: generate netlink code
  wireguard: uapi: generate header with ynl-gen
  wireguard: uapi: move flag enums
  wireguard: uapi: move enum wg_cmd
  wireguard: netlink: add YNL specification
  selftests: drv-net: Fix tolerance calculation in devlink_rate_tc_bw.py
  selftests: drv-net: Fix and clarify TC bandwidth split in devlink_rate_tc_bw.py
  selftests: drv-net: Set shell=True for sysfs writes in devlink_rate_tc_bw.py
  selftests: drv-net: Use Iperf3Runner in devlink_rate_tc_bw.py
  selftests: drv-net: introduce Iperf3Runner for measurement use cases
  selftests: drv-net: Add devlink_rate_tc_bw.py to TEST_PROGS
  net: ps3_gelic_net: Use napi_alloc_skb() and napi_gro_receive()
  Documentation: net: dsa: mention simple HSR offload helpers
  Documentation: net: dsa: mention availability of RedBox
  ...
</content>
</entry>
<entry>
<title>tcp: add net.ipv4.tcp_rcvbuf_low_rtt</title>
<updated>2025-11-21T01:44:23+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2025-11-19T08:48:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=ecfea98b7d0d56c5bf2df3fc02c5501afa5cef6f'/>
<id>urn:sha1:ecfea98b7d0d56c5bf2df3fc02c5501afa5cef6f</id>
<content type='text'>
This is a follow up of commit aa251c84636c ("tcp: fix too slow
tcp_rcvbuf_grow() action") which brought again the issue that I tried
to fix in commit 65c5287892e9 ("tcp: fix sk_rcvbuf overshoot")

We also recently increased tcp_rmem[2] to 32 MB in commit 572be9bf9d0d
("tcp: increase tcp_rmem[2] to 32 MB")

Idea of this patch is to not let tcp_rcvbuf_grow() grow sk-&gt;sk_rcvbuf
too fast for small RTT flows. If sk-&gt;sk_rcvbuf is too big, this can
force NIC driver to not recycle pages from their page pool, and also
can cause cache evictions for DDIO enabled cpus/NIC, as receivers
are usually slower than senders.

Add net.ipv4.tcp_rcvbuf_low_rtt sysctl, set by default to 1000 usec (1 ms)

If RTT if smaller than the sysctl value, use the RTT/tcp_rcvbuf_low_rtt
ratio to control sk_rcvbuf inflation.

Tested:

Pair of hosts with a 200Gbit IDPF NIC. Using netperf/netserver

Client initiates 8 TCP bulk flows, asking netserver to use CPU #10 only.

super_netperf 8 -H server -T,10 -l 30

On server, use perf -e tcp:tcp_rcvbuf_grow while test is running.

Before:

sysctl -w net.ipv4.tcp_rcvbuf_low_rtt=1
perf record -a -e tcp:tcp_rcvbuf_grow sleep 30 ; perf script|tail -20|cut -c30-230
 1153.051201: tcp:tcp_rcvbuf_grow: time=398 rtt_us=382 copied=6905856 inq=180224 space=6115328 ooo=0 scaling_ratio=240 rcvbuf=27666235 rcv_ssthresh=25878235 window_clamp=25937095 rcv_wnd=25600000 famil
 1153.138752: tcp:tcp_rcvbuf_grow: time=446 rtt_us=413 copied=5529600 inq=180224 space=4505600 ooo=0 scaling_ratio=240 rcvbuf=23068672 rcv_ssthresh=21571860 window_clamp=21626880 rcv_wnd=21286912 famil
 1153.361484: tcp:tcp_rcvbuf_grow: time=415 rtt_us=380 copied=7061504 inq=204800 space=6725632 ooo=0 scaling_ratio=240 rcvbuf=27666235 rcv_ssthresh=25878235 window_clamp=25937095 rcv_wnd=25600000 famil
 1153.457642: tcp:tcp_rcvbuf_grow: time=483 rtt_us=421 copied=5885952 inq=720896 space=4407296 ooo=0 scaling_ratio=240 rcvbuf=23763511 rcv_ssthresh=22223271 window_clamp=22278291 rcv_wnd=21430272 famil
 1153.466002: tcp:tcp_rcvbuf_grow: time=308 rtt_us=281 copied=3244032 inq=180224 space=2883584 ooo=0 scaling_ratio=240 rcvbuf=44854314 rcv_ssthresh=41992059 window_clamp=42050919 rcv_wnd=41713664 famil
 1153.747792: tcp:tcp_rcvbuf_grow: time=394 rtt_us=332 copied=4460544 inq=585728 space=3063808 ooo=0 scaling_ratio=240 rcvbuf=44854314 rcv_ssthresh=41992059 window_clamp=42050919 rcv_wnd=41373696 famil
 1154.260747: tcp:tcp_rcvbuf_grow: time=652 rtt_us=226 copied=10977280 inq=737280 space=9486336 ooo=0 scaling_ratio=240 rcvbuf=31165538 rcv_ssthresh=29197743 window_clamp=29217691 rcv_wnd=28368896 fami
 1154.375019: tcp:tcp_rcvbuf_grow: time=461 rtt_us=443 copied=7573504 inq=507904 space=6856704 ooo=0 scaling_ratio=240 rcvbuf=27666235 rcv_ssthresh=25878235 window_clamp=25937095 rcv_wnd=25288704 famil
 1154.463072: tcp:tcp_rcvbuf_grow: time=494 rtt_us=408 copied=7983104 inq=200704 space=7065600 ooo=0 scaling_ratio=240 rcvbuf=27666235 rcv_ssthresh=25878235 window_clamp=25937095 rcv_wnd=25579520 famil
 1154.474658: tcp:tcp_rcvbuf_grow: time=507 rtt_us=459 copied=5586944 inq=540672 space=4718592 ooo=0 scaling_ratio=240 rcvbuf=17852266 rcv_ssthresh=16692999 window_clamp=16736499 rcv_wnd=16056320 famil
 1154.584657: tcp:tcp_rcvbuf_grow: time=494 rtt_us=427 copied=8126464 inq=204800 space=7782400 ooo=0 scaling_ratio=240 rcvbuf=27666235 rcv_ssthresh=25878235 window_clamp=25937095 rcv_wnd=25600000 famil
 1154.702117: tcp:tcp_rcvbuf_grow: time=480 rtt_us=406 copied=5734400 inq=180224 space=5349376 ooo=0 scaling_ratio=240 rcvbuf=23068672 rcv_ssthresh=21571860 window_clamp=21626880 rcv_wnd=21286912 famil
 1155.941595: tcp:tcp_rcvbuf_grow: time=717 rtt_us=670 copied=11042816 inq=3784704 space=7159808 ooo=0 scaling_ratio=240 rcvbuf=19581357 rcv_ssthresh=18333222 window_clamp=18357522 rcv_wnd=14614528 fam
 1156.384735: tcp:tcp_rcvbuf_grow: time=529 rtt_us=473 copied=9011200 inq=180224 space=7258112 ooo=0 scaling_ratio=240 rcvbuf=19581357 rcv_ssthresh=18333222 window_clamp=18357522 rcv_wnd=18018304 famil
 1157.821676: tcp:tcp_rcvbuf_grow: time=529 rtt_us=272 copied=8224768 inq=602112 space=6545408 ooo=0 scaling_ratio=240 rcvbuf=67000000 rcv_ssthresh=62793576 window_clamp=62812500 rcv_wnd=62115840 famil
 1158.906379: tcp:tcp_rcvbuf_grow: time=710 rtt_us=445 copied=11845632 inq=540672 space=10240000 ooo=0 scaling_ratio=240 rcvbuf=31165538 rcv_ssthresh=29205935 window_clamp=29217691 rcv_wnd=28536832 fam
 1164.600160: tcp:tcp_rcvbuf_grow: time=841 rtt_us=430 copied=12976128 inq=1290240 space=11304960 ooo=0 scaling_ratio=240 rcvbuf=31165538 rcv_ssthresh=29212591 window_clamp=29217691 rcv_wnd=27856896 fa
 1165.163572: tcp:tcp_rcvbuf_grow: time=845 rtt_us=800 copied=12632064 inq=540672 space=7921664 ooo=0 scaling_ratio=240 rcvbuf=27666235 rcv_ssthresh=25912795 window_clamp=25937095 rcv_wnd=25260032 fami
 1165.653464: tcp:tcp_rcvbuf_grow: time=388 rtt_us=309 copied=4493312 inq=180224 space=3874816 ooo=0 scaling_ratio=240 rcvbuf=44854314 rcv_ssthresh=41995899 window_clamp=42050919 rcv_wnd=41713664 famil
 1166.651211: tcp:tcp_rcvbuf_grow: time=556 rtt_us=553 copied=6328320 inq=540672 space=5554176 ooo=0 scaling_ratio=240 rcvbuf=23068672 rcv_ssthresh=21571860 window_clamp=21626880 rcv_wnd=20946944 famil

After:

sysctl -w net.ipv4.tcp_rcvbuf_low_rtt=1000
perf record -a -e tcp:tcp_rcvbuf_grow sleep 30 ; perf script|tail -20|cut -c30-230
 1457.053149: tcp:tcp_rcvbuf_grow: time=128 rtt_us=24 copied=1441792 inq=40960 space=1269760 ooo=0 scaling_ratio=240 rcvbuf=2960741 rcv_ssthresh=2605474 window_clamp=2775694 rcv_wnd=2568192 family=AF_I
 1458.000778: tcp:tcp_rcvbuf_grow: time=128 rtt_us=31 copied=1441792 inq=24576 space=1400832 ooo=0 scaling_ratio=240 rcvbuf=3060163 rcv_ssthresh=2810042 window_clamp=2868902 rcv_wnd=2674688 family=AF_I
 1458.088059: tcp:tcp_rcvbuf_grow: time=190 rtt_us=110 copied=3227648 inq=385024 space=2781184 ooo=0 scaling_ratio=240 rcvbuf=6728240 rcv_ssthresh=6252705 window_clamp=6307725 rcv_wnd=5799936 family=AF
 1458.148549: tcp:tcp_rcvbuf_grow: time=232 rtt_us=129 copied=3956736 inq=237568 space=2842624 ooo=0 scaling_ratio=240 rcvbuf=6731333 rcv_ssthresh=6252705 window_clamp=6310624 rcv_wnd=5918720 family=AF
 1458.466861: tcp:tcp_rcvbuf_grow: time=193 rtt_us=83 copied=2949120 inq=180224 space=2457600 ooo=0 scaling_ratio=240 rcvbuf=5751438 rcv_ssthresh=5357689 window_clamp=5391973 rcv_wnd=5054464 family=AF_
 1458.775476: tcp:tcp_rcvbuf_grow: time=257 rtt_us=127 copied=4304896 inq=352256 space=3346432 ooo=0 scaling_ratio=240 rcvbuf=8067131 rcv_ssthresh=7523275 window_clamp=7562935 rcv_wnd=7061504 family=AF
 1458.776631: tcp:tcp_rcvbuf_grow: time=200 rtt_us=96 copied=3260416 inq=143360 space=2768896 ooo=0 scaling_ratio=240 rcvbuf=6397256 rcv_ssthresh=5938567 window_clamp=5997427 rcv_wnd=5828608 family=AF_
 1459.707973: tcp:tcp_rcvbuf_grow: time=215 rtt_us=96 copied=2506752 inq=163840 space=1388544 ooo=0 scaling_ratio=240 rcvbuf=3068867 rcv_ssthresh=2768282 window_clamp=2877062 rcv_wnd=2555904 family=AF_
 1460.246494: tcp:tcp_rcvbuf_grow: time=231 rtt_us=80 copied=3756032 inq=204800 space=3117056 ooo=0 scaling_ratio=240 rcvbuf=7288091 rcv_ssthresh=6773725 window_clamp=6832585 rcv_wnd=6471680 family=AF_
 1460.714596: tcp:tcp_rcvbuf_grow: time=270 rtt_us=110 copied=4714496 inq=311296 space=3719168 ooo=0 scaling_ratio=240 rcvbuf=8957739 rcv_ssthresh=8339020 window_clamp=8397880 rcv_wnd=7933952 family=AF
 1462.029977: tcp:tcp_rcvbuf_grow: time=101 rtt_us=19 copied=1105920 inq=40960 space=1036288 ooo=0 scaling_ratio=240 rcvbuf=2338970 rcv_ssthresh=2091684 window_clamp=2192784 rcv_wnd=1986560 family=AF_I
 1462.802385: tcp:tcp_rcvbuf_grow: time=89 rtt_us=45 copied=1069056 inq=0 space=1064960 ooo=0 scaling_ratio=240 rcvbuf=2338970 rcv_ssthresh=2091684 window_clamp=2192784 rcv_wnd=2035712 family=AF_INET6
 1462.918648: tcp:tcp_rcvbuf_grow: time=105 rtt_us=33 copied=1441792 inq=180224 space=1069056 ooo=0 scaling_ratio=240 rcvbuf=2383282 rcv_ssthresh=2091684 window_clamp=2234326 rcv_wnd=1896448 family=AF_
 1463.222533: tcp:tcp_rcvbuf_grow: time=273 rtt_us=144 copied=4603904 inq=385024 space=3469312 ooo=0 scaling_ratio=240 rcvbuf=8422564 rcv_ssthresh=7891053 window_clamp=7896153 rcv_wnd=7409664 family=AF
 1466.519312: tcp:tcp_rcvbuf_grow: time=130 rtt_us=23 copied=1343488 inq=0 space=1261568 ooo=0 scaling_ratio=240 rcvbuf=2780158 rcv_ssthresh=2493778 window_clamp=2606398 rcv_wnd=2494464 family=AF_INET6
 1466.681003: tcp:tcp_rcvbuf_grow: time=128 rtt_us=21 copied=1441792 inq=12288 space=1343488 ooo=0 scaling_ratio=240 rcvbuf=2932027 rcv_ssthresh=2578555 window_clamp=2748775 rcv_wnd=2568192 family=AF_I
 1470.689959: tcp:tcp_rcvbuf_grow: time=255 rtt_us=122 copied=3932160 inq=204800 space=3551232 ooo=0 scaling_ratio=240 rcvbuf=8182038 rcv_ssthresh=7647384 window_clamp=7670660 rcv_wnd=7442432 family=AF
 1471.754154: tcp:tcp_rcvbuf_grow: time=188 rtt_us=95 copied=2138112 inq=577536 space=1429504 ooo=0 scaling_ratio=240 rcvbuf=3113650 rcv_ssthresh=2806426 window_clamp=2919046 rcv_wnd=2248704 family=AF_
 1476.813542: tcp:tcp_rcvbuf_grow: time=269 rtt_us=99 copied=3088384 inq=180224 space=2564096 ooo=0 scaling_ratio=240 rcvbuf=6219470 rcv_ssthresh=5771893 window_clamp=5830753 rcv_wnd=5509120 family=AF_
 1477.738309: tcp:tcp_rcvbuf_grow: time=166 rtt_us=54 copied=1777664 inq=180224 space=1417216 ooo=0 scaling_ratio=240 rcvbuf=3117118 rcv_ssthresh=2874958 window_clamp=2922298 rcv_wnd=2613248 family=AF_

We can see sk_rcvbuf values are much smaller, and that rtt_us (estimation of rtt
from a receiver point of view) is kept small, instead of being bloated.

No difference in throughput.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Kuniyuki Iwashima &lt;kuniyu@google.com&gt;
Tested-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Link: https://patch.msgid.link/20251119084813.3684576-3-edumazet@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
</entry>
<entry>
<title>tcp: tcp_moderate_rcvbuf is only used in rx path</title>
<updated>2025-11-21T01:44:23+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2025-11-19T08:48:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=6d5dea68246ecb190a50a7fecbaf7f8c1ddb15e4'/>
<id>urn:sha1:6d5dea68246ecb190a50a7fecbaf7f8c1ddb15e4</id>
<content type='text'>
sysctl_tcp_moderate_rcvbuf is only used from tcp_rcvbuf_grow().

Move it to netns_ipv4_read_rx group.

Remove various CACHELINE_ASSERT_GROUP_SIZE() from netns_ipv4_struct_check(),
as they have no real benefit but cause pain for all changes.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Kuniyuki Iwashima &lt;kuniyu@google.com&gt;
Link: https://patch.msgid.link/20251119084813.3684576-2-edumazet@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
</entry>
<entry>
<title>nstree: assign fixed ids to the initial namespaces</title>
<updated>2025-11-03T16:41:17+00:00</updated>
<author>
<name>Christian Brauner</name>
<email>brauner@kernel.org</email>
</author>
<published>2025-10-29T12:20:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=3760342fd6312416491d536144e39297fa5b1950'/>
<id>urn:sha1:3760342fd6312416491d536144e39297fa5b1950</id>
<content type='text'>
The initial set of namespace comes with fixed inode numbers making it
easy for userspace to identify them solely based on that information.
This has long preceeded anything here.

Similarly, let's assign fixed namespace ids for the initial namespaces.

Kill the cookie and use a sequentially increasing number. This has the
nice side-effect that the owning user namespace will always have a
namespace id that is smaller than any of it's descendant namespaces.

Link: https://patch.msgid.link/20251029-work-namespace-nstree-listns-v4-15-2e6f823ebdc0@kernel.org
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</content>
</entry>
<entry>
<title>net: add /proc/sys/net/core/txq_reselection_ms control</title>
<updated>2025-10-15T16:04:21+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2025-10-13T15:22:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=2ddef3462b3a5d62e5485e22ce128a5c02276438'/>
<id>urn:sha1:2ddef3462b3a5d62e5485e22ce128a5c02276438</id>
<content type='text'>
Add a new sysctl to control how often a queue reselection
can happen even if a flow has a persistent queue of skbs
in a Qdisc or NIC queue.

A value of zero means the feature is disabled.

Default is 1000 (1 second).

This sysctl is used in the following patch.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Reviewed-by: Kuniyuki Iwashima &lt;kuniyu@google.com&gt;
Link: https://patch.msgid.link/20251013152234.842065-4-edumazet@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
</entry>
<entry>
<title>Merge tag 'namespace-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs</title>
<updated>2025-09-29T18:20:29+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-09-29T18:20:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=18b19abc3709b109676ffd1f48dcd332c2e477d4'/>
<id>urn:sha1:18b19abc3709b109676ffd1f48dcd332c2e477d4</id>
<content type='text'>
Pull namespace updates from Christian Brauner:
 "This contains a larger set of changes around the generic namespace
  infrastructure of the kernel.

  Each specific namespace type (net, cgroup, mnt, ...) embedds a struct
  ns_common which carries the reference count of the namespace and so
  on.

  We open-coded and cargo-culted so many quirks for each namespace type
  that it just wasn't scalable anymore. So given there's a bunch of new
  changes coming in that area I've started cleaning all of this up.

  The core change is to make it possible to correctly initialize every
  namespace uniformly and derive the correct initialization settings
  from the type of the namespace such as namespace operations, namespace
  type and so on. This leaves the new ns_common_init() function with a
  single parameter which is the specific namespace type which derives
  the correct parameters statically. This also means the compiler will
  yell as soon as someone does something remotely fishy.

  The ns_common_init() addition also allows us to remove ns_alloc_inum()
  and drops any special-casing of the initial network namespace in the
  network namespace initialization code that Linus complained about.

  Another part is reworking the reference counting. The reference
  counting was open-coded and copy-pasted for each namespace type even
  though they all followed the same rules. This also removes all open
  accesses to the reference count and makes it private and only uses a
  very small set of dedicated helpers to manipulate them just like we do
  for e.g., files.

  In addition this generalizes the mount namespace iteration
  infrastructure introduced a few cycles ago. As reminder, the vfs makes
  it possible to iterate sequentially and bidirectionally through all
  mount namespaces on the system or all mount namespaces that the caller
  holds privilege over. This allow userspace to iterate over all mounts
  in all mount namespaces using the listmount() and statmount() system
  call.

  Each mount namespace has a unique identifier for the lifetime of the
  systems that is exposed to userspace. The network namespace also has a
  unique identifier working exactly the same way. This extends the
  concept to all other namespace types.

  The new nstree type makes it possible to lookup namespaces purely by
  their identifier and to walk the namespace list sequentially and
  bidirectionally for all namespace types, allowing userspace to iterate
  through all namespaces. Looking up namespaces in the namespace tree
  works completely locklessly.

  This also means we can move the mount namespace onto the generic
  infrastructure and remove a bunch of code and members from struct
  mnt_namespace itself.

  There's a bunch of stuff coming on top of this in the future but for
  now this uses the generic namespace tree to extend a concept
  introduced first for pidfs a few cycles ago. For a while now we have
  supported pidfs file handles for pidfds. This has proven to be very
  useful.

  This extends the concept to cover namespaces as well. It is possible
  to encode and decode namespace file handles using the common
  name_to_handle_at() and open_by_handle_at() apis.

  As with pidfs file handles, namespace file handles are exhaustive,
  meaning it is not required to actually hold a reference to nsfs in
  able to decode aka open_by_handle_at() a namespace file handle.
  Instead the FD_NSFS_ROOT constant can be passed which will let the
  kernel grab a reference to the root of nsfs internally and thus decode
  the file handle.

  Namespaces file descriptors can already be derived from pidfds which
  means they aren't subject to overmount protection bugs. IOW, it's
  irrelevant if the caller would not have access to an appropriate
  /proc/&lt;pid&gt;/ns/ directory as they could always just derive the
  namespace based on a pidfd already.

  It has the same advantage as pidfds. It's possible to reliably and for
  the lifetime of the system refer to a namespace without pinning any
  resources and to compare them trivially.

  Permission checking is kept simple. If the caller is located in the
  namespace the file handle refers to they are able to open it otherwise
  they must hold privilege over the owning namespace of the relevant
  namespace.

  The namespace file handle layout is exposed as uapi and has a stable
  and extensible format. For now it simply contains the namespace
  identifier, the namespace type, and the inode number. The stable
  format means that userspace may construct its own namespace file
  handles without going through name_to_handle_at() as they are already
  allowed for pidfs and cgroup file handles"

* tag 'namespace-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (65 commits)
  ns: drop assert
  ns: move ns type into struct ns_common
  nstree: make struct ns_tree private
  ns: add ns_debug()
  ns: simplify ns_common_init() further
  cgroup: add missing ns_common include
  ns: use inode initializer for initial namespaces
  selftests/namespaces: verify initial namespace inode numbers
  ns: rename to __ns_ref
  nsfs: port to ns_ref_*() helpers
  net: port to ns_ref_*() helpers
  uts: port to ns_ref_*() helpers
  ipv4: use check_net()
  net: use check_net()
  net-sysfs: use check_net()
  user: port to ns_ref_*() helpers
  time: port to ns_ref_*() helpers
  pid: port to ns_ref_*() helpers
  ipc: port to ns_ref_*() helpers
  cgroup: port to ns_ref_*() helpers
  ...
</content>
</entry>
<entry>
<title>ns: move ns type into struct ns_common</title>
<updated>2025-09-25T07:23:54+00:00</updated>
<author>
<name>Christian Brauner</name>
<email>brauner@kernel.org</email>
</author>
<published>2025-09-24T11:33:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=4055526d35746ce8b04bfa5e14e14f28bb163186'/>
<id>urn:sha1:4055526d35746ce8b04bfa5e14e14f28bb163186</id>
<content type='text'>
It's misplaced in struct proc_ns_operations and ns-&gt;ops might be NULL if
the namespace is compiled out but we still want to know the type of the
namespace for the initial namespace struct.

Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</content>
</entry>
<entry>
<title>ns: simplify ns_common_init() further</title>
<updated>2025-09-22T12:47:10+00:00</updated>
<author>
<name>Christian Brauner</name>
<email>brauner@kernel.org</email>
</author>
<published>2025-09-22T12:42:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=d7610cb7454bbd8bf6d58f71b0ed57155d3c545f'/>
<id>urn:sha1:d7610cb7454bbd8bf6d58f71b0ed57155d3c545f</id>
<content type='text'>
Simply derive the ns operations from the namespace type.

Acked-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</content>
</entry>
<entry>
<title>net: use check_net()</title>
<updated>2025-09-19T14:22:37+00:00</updated>
<author>
<name>Christian Brauner</name>
<email>brauner@kernel.org</email>
</author>
<published>2025-09-18T10:11:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=dc41b844da530e94f5b8384deb2af602cbeb312a'/>
<id>urn:sha1:dc41b844da530e94f5b8384deb2af602cbeb312a</id>
<content type='text'>
Don't directly acess the namespace count. There's even a dedicated
helper for this.

Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</content>
</entry>
<entry>
<title>ns: add ns_common_free()</title>
<updated>2025-09-19T14:22:36+00:00</updated>
<author>
<name>Christian Brauner</name>
<email>brauner@kernel.org</email>
</author>
<published>2025-09-17T10:28:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=be5f21d3985f00827e09b798f7a07ebd6dd7f54a'/>
<id>urn:sha1:be5f21d3985f00827e09b798f7a07ebd6dd7f54a</id>
<content type='text'>
And drop ns_free_inum(). Anything common that can be wasted centrally
should be wasted in the new common helper.

Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</content>
</entry>
</feed>
