[ Upstream commit b49960a05e32121d29316cfdf653894b88ac9190 ] tcp_adv_win_scale default value is 2, meaning we expect a good citizen skb to have skb->len / skb->truesize ratio of 75% (3/4) In 2.6 kernels we (mis)accounted for typical MSS=1460 frame : 1536 + 64 + 256 = 1856 'estimated truesize', and 1856 * 3/4 = 1392. So these skbs were considered as not bloated. With recent truesize fixes, a typical MSS=1460 frame truesize is now the more precise : 2048 + 256 = 2304. But 2304 * 3/4 = 1728. So these skb are not good citizen anymore, because 1460 < 1728 (GRO can escape this problem because it build skbs with a too low truesize.) This also means tcp advertises a too optimistic window for a given allocated rcvspace : When receiving frames, sk_rmem_alloc can hit sk_rcvbuf limit and we call tcp_prune_queue()/tcp_collapse() too often, especially when application is slow to drain its receive queue or in case of losses (netperf is fast, scp is slow). This is a major latency source. We should adjust the len/truesize ratio to 50% instead of 75% This patch : 1) changes tcp_adv_win_scale default to 1 instead of 2 2) increase tcp_rmem[2] limit from 4MB to 6MB to take into account better truesize tracking and to allow autotuning tcp receive window to reach same value than before. Note that same amount of kernel memory is consumed compared to 2.6 kernels. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Since commit c5ed63d66f24(tcp: fix three tcp sysctls tuning), sysctl_max_syn_backlog is determined by tcp_hashinfo->ehash_mask, and the minimal value is 128, and it will increase in proportion to the memory of machine. The original description for tcp_max_syn_backlog and sysctl_max_syn_backlog are out of date. Changelog: V2: update description for sysctl_max_syn_backlog Signed-off-by: Weiping Pan <panweiping3@gmail.com> Reviewed-by: Shan Wei <shanwei88@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Small fix in Documentation, since min_pmtu is 512 + 20 + 20 = 552 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Reported-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Simon Horman <horms@verge.net.au> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Also reword the test to make it read more easily (to me) Signed-off-by: Simon Horman <horms@verge.net.au> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add missing documentation for conntrack, snat_reroute and sync_version. Also fix up a typo, IPVS_DEBUG should be IP_VS_DEBUG. Acked-by: Julian Anastasov <ja@ssi.bg> Acked-by Hans Schillstrom <hans@schillstrom.com> Signed-off-by: Simon Horman <horms@verge.net.au> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Updated qlcnic's license file. Signed-off-by: Sritej Velaga <sritej.velaga@qlogic.com> Signed-off-by: Anirban Chakraborty <anirban.chakraborty@qlogic.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1745 commits) dp83640: free packet queues on remove dp83640: use proper function to free transmit time stamping packets ipv6: Do not use routes from locally generated RAs |PATCH net-next] tg3: add tx_dropped counter be2net: don't create multiple RX/TX rings in multi channel mode be2net: don't create multiple TXQs in BE2 be2net: refactor VF setup/teardown code into be_vf_setup/clear() be2net: add vlan/rx-mode/flow-control config to be_setup() net_sched: cls_flow: use skb_header_pointer() ipv4: avoid useless call of the function check_peer_pmtu TCP: remove TCP_DEBUG net: Fix driver name for mdio-gpio.c ipv4: tcp: fix TOS value in ACK messages sent from TIME_WAIT rtnetlink: Add missing manual netlink notification in dev_change_net_namespaces ipv4: fix ipsec forward performance regression jme: fix irq storm after suspend/resume route: fix ICMP redirect validation net: hold sock reference while processing tx timestamps tcp: md5: add more const attributes Add ethtool -g support to virtio_net ... Fix up conflicts in: - drivers/net/Kconfig: The split-up generated a trivial conflict with removal of a stale reference to Documentation/networking/net-modules.txt. Remove it from the new location instead. - fs/sysfs/dir.c: Fairly nasty conflicts with the sysfs rb-tree usage, conflicting with Eric Biederman's changes for tagged directories.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (59 commits) MAINTAINERS: linux-m32r is moderated for non-subscribers linux@lists.openrisc.net is moderated for non-subscribers Drop default from "DM365 codec select" choice parisc: Kconfig: cleanup Kernel page size default Kconfig: remove redundant CONFIG_ prefix on two symbols cris: remove arch/cris/arch-v32/lib/nand_init.S microblaze: add missing CONFIG_ prefixes h8300: drop puzzling Kconfig dependencies MAINTAINERS: microblaze-uclinux@itee.uq.edu.au is moderated for non-subscribers tty: drop superfluous dependency in Kconfig ARM: mxc: fix Kconfig typo 'i.MX51' Fix file references in Kconfig files aic7xxx: fix Kconfig references to READMEs Fix file references in drivers/ide/ thinkpad_acpi: Fix printk typo 'bluestooth' bcmring: drop commented out line in Kconfig btmrvl_sdio: fix typo 'btmrvl_sdio_sd6888' doc: raw1394: Trivial typo fix CIFS: Don't free volume_info->UNC until we are entirely done with it. treewide: Correct spelling of successfully in comments ...
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com> Signed-off-by: David S. Miller <davem@davemloft.net>