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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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583396f4ca
Add a new attribute to control the fq qdisc hrtimer slack. Default is set to 10 usec. When/if packets are throttled, fq set up an hrtimer that can lead to one interrupt per packet in the throttled queue. By using a timer slack, we allow better use of timer interrupts, by giving them a chance to call multiple timer callbacks at each hardware interrupt. Also, giving a slack allows FQ to dequeue batches of packets instead of a single one, thus increasing xmit_more efficiency. This has no negative effect on the rate a TCP flow can sustain, since each TCP flow maintains its own precise vtime (tp->tcp_wstamp_ns) v2: added strict netlink checking (as feedback from Jakub Kicinski) Tested: 1000 concurrent flows all using paced packets. 1,000,000 packets sent per second. Before the patch : $ vmstat 2 10 procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 0 0 0 60726784 23628 3485992 0 0 138 1 977 535 0 12 87 0 0 0 0 0 60714700 23628 3485628 0 0 0 0 1568827 26462 0 22 78 0 0 1 0 0 60716012 23628 3485656 0 0 0 0 1570034 26216 0 22 78 0 0 0 0 0 60722420 23628 3485492 0 0 0 0 1567230 26424 0 22 78 0 0 0 0 0 60727484 23628 3485556 0 0 0 0 1568220 26200 0 22 78 0 0 2 0 0 60718900 23628 3485380 0 0 0 40 1564721 26630 0 22 78 0 0 2 0 0 60718096 23628 3485332 0 0 0 0 1562593 26432 0 22 78 0 0 0 0 0 60719608 23628 3485064 0 0 0 0 1563806 26238 0 22 78 0 0 1 0 0 60722876 23628 3485236 0 0 0 130 1565874 26566 0 22 78 0 0 1 0 0 60722752 23628 3484908 0 0 0 0 1567646 26247 0 22 78 0 0 After the patch, slack of 10 usec, we can see a reduction of interrupts per second, and a small decrease of reported cpu usage. $ vmstat 2 10 procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 1 0 0 60722564 23628 3484728 0 0 133 1 696 545 0 13 87 0 0 1 0 0 60722568 23628 3484824 0 0 0 0 977278 25469 0 20 80 0 0 0 0 0 60716396 23628 3484764 0 0 0 0 979997 25326 0 20 80 0 0 0 0 0 60713844 23628 3484960 0 0 0 0 981394 25249 0 20 80 0 0 2 0 0 60720468 23628 3484916 0 0 0 0 982860 25062 0 20 80 0 0 1 0 0 60721236 23628 3484856 0 0 0 0 982867 25100 0 20 80 0 0 1 0 0 60722400 23628 3484456 0 0 0 8 982698 25303 0 20 80 0 0 0 0 0 60715396 23628 3484428 0 0 0 0 981777 25176 0 20 80 0 0 0 0 0 60716520 23628 3486544 0 0 0 36 978965 27857 0 21 79 0 0 0 0 0 60719592 23628 3486516 0 0 0 22 977318 25106 0 20 80 0 0 Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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| 6lowpan | ||
| 9p | ||
| 802 | ||
| 8021q | ||
| appletalk | ||
| atm | ||
| ax25 | ||
| batman-adv | ||
| bluetooth | ||
| bpf | ||
| bpfilter | ||
| bridge | ||
| caif | ||
| can | ||
| ceph | ||
| core | ||
| dcb | ||
| dccp | ||
| decnet | ||
| dns_resolver | ||
| dsa | ||
| ethernet | ||
| ethtool | ||
| hsr | ||
| ieee802154 | ||
| ife | ||
| ipv4 | ||
| ipv6 | ||
| iucv | ||
| kcm | ||
| key | ||
| l2tp | ||
| l3mdev | ||
| lapb | ||
| llc | ||
| mac80211 | ||
| mac802154 | ||
| mpls | ||
| mptcp | ||
| ncsi | ||
| netfilter | ||
| netlabel | ||
| netlink | ||
| netrom | ||
| nfc | ||
| nsh | ||
| openvswitch | ||
| packet | ||
| phonet | ||
| psample | ||
| qrtr | ||
| rds | ||
| rfkill | ||
| rose | ||
| rxrpc | ||
| sched | ||
| sctp | ||
| smc | ||
| strparser | ||
| sunrpc | ||
| switchdev | ||
| tipc | ||
| tls | ||
| unix | ||
| vmw_vsock | ||
| wimax | ||
| wireless | ||
| x25 | ||
| xdp | ||
| xfrm | ||
| compat.c | ||
| Kconfig | ||
| Makefile | ||
| socket.c | ||
| sysctl_net.c | ||