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2018-06-28netem: slotting with non-uniform distributionYousuk Seung1-24/+49
Extend slotting with support for non-uniform distributions. This is similar to netem's non-uniform distribution delay feature. Commit f043efeae2f1 ("netem: support delivering packets in delayed time slots") added the slotting feature to approximate the behaviors of media with packet aggregation but only supported a uniform distribution for delays between transmission attempts. Tests with TCP BBR with emulated wifi links with non-uniform distributions produced more useful results. Syntax: slot dist DISTRIBUTION DELAY JITTER [packets MAX_PACKETS] \ [bytes MAX_BYTES] The syntax and use of the distribution table is the same as in the non-uniform distribution delay feature. A file DISTRIBUTION must be present in TC_LIB_DIR (e.g. /usr/lib/tc) containing numbers scaled by NETEM_DIST_SCALE. A random value x is selected from the table and it takes DELAY + ( x * JITTER ) as delay. Correlation between values is not supported. Examples: Normal distribution delay with mean = 800us and stdev = 100us. > tc qdisc add dev eth0 root netem slot dist normal 800us 100us Optionally set the max slot size in bytes and/or packets. > tc qdisc add dev eth0 root netem slot dist normal 800us 100us \ bytes 64k packets 42 Signed-off-by: Yousuk Seung <ysseung@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-07sch_netem: fix skb leak in netem_enqueue()Alexey Kodanev1-1/+1
When we exceed current packets limit and we have more than one segment in the list returned by skb_gso_segment(), netem drops only the first one, skipping the rest, hence kmemleak reports: unreferenced object 0xffff880b5d23b600 (size 1024): comm "softirq", pid 0, jiffies 4384527763 (age 2770.629s) hex dump (first 32 bytes): 00 80 23 5d 0b 88 ff ff 00 00 00 00 00 00 00 00 ..#]............ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000d8a19b9d>] __alloc_skb+0xc9/0x520 [<000000001709b32f>] skb_segment+0x8c8/0x3710 [<00000000c7b9bb88>] tcp_gso_segment+0x331/0x1830 [<00000000c921cba1>] inet_gso_segment+0x476/0x1370 [<000000008b762dd4>] skb_mac_gso_segment+0x1f9/0x510 [<000000002182660a>] __skb_gso_segment+0x1dd/0x620 [<00000000412651b9>] netem_enqueue+0x1536/0x2590 [sch_netem] [<0000000005d3b2a9>] __dev_queue_xmit+0x1167/0x2120 [<00000000fc5f7327>] ip_finish_output2+0x998/0xf00 [<00000000d309e9d3>] ip_output+0x1aa/0x2c0 [<000000007ecbd3a4>] tcp_transmit_skb+0x18db/0x3670 [<0000000042d2a45f>] tcp_write_xmit+0x4d4/0x58c0 [<0000000056a44199>] tcp_tasklet_func+0x3d9/0x540 [<0000000013d06d02>] tasklet_action+0x1ca/0x250 [<00000000fcde0b8b>] __do_softirq+0x1b4/0x5a3 [<00000000e7ed027c>] irq_exit+0x1e2/0x210 Fix it by adding the rest of the segments, if any, to skb 'to_free' list. Add new __qdisc_drop_all() and qdisc_drop_all() functions because they can be useful in the future if we need to drop segmented GSO packets in other places. Fixes: 6071bd1aa13e ("netem: Segment GSO packets on enqueue") Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-07sch_netem: Bug fixing in calculating Netem intervalMd. Islam1-1/+1
In Kernel 4.15.0+, Netem does not work properly. Netem setup: tc qdisc add dev h1-eth0 root handle 1: netem delay 10ms 2ms Result: PING 172.16.101.2 (172.16.101.2) 56(84) bytes of data. 64 bytes from 172.16.101.2: icmp_seq=1 ttl=64 time=22.8 ms 64 bytes from 172.16.101.2: icmp_seq=2 ttl=64 time=10.9 ms 64 bytes from 172.16.101.2: icmp_seq=3 ttl=64 time=10.9 ms 64 bytes from 172.16.101.2: icmp_seq=5 ttl=64 time=11.4 ms 64 bytes from 172.16.101.2: icmp_seq=6 ttl=64 time=11.8 ms 64 bytes from 172.16.101.2: icmp_seq=4 ttl=64 time=4303 ms 64 bytes from 172.16.101.2: icmp_seq=10 ttl=64 time=11.2 ms 64 bytes from 172.16.101.2: icmp_seq=11 ttl=64 time=10.3 ms 64 bytes from 172.16.101.2: icmp_seq=7 ttl=64 time=4304 ms 64 bytes from 172.16.101.2: icmp_seq=8 ttl=64 time=4303 ms Patch: (rnd % (2 * sigma)) - sigma was overflowing s32. After applying the patch, I found following output which is desirable. PING 172.16.101.2 (172.16.101.2) 56(84) bytes of data. 64 bytes from 172.16.101.2: icmp_seq=1 ttl=64 time=21.1 ms 64 bytes from 172.16.101.2: icmp_seq=2 ttl=64 time=8.46 ms 64 bytes from 172.16.101.2: icmp_seq=3 ttl=64 time=9.00 ms 64 bytes from 172.16.101.2: icmp_seq=4 ttl=64 time=11.8 ms 64 bytes from 172.16.101.2: icmp_seq=5 ttl=64 time=8.36 ms 64 bytes from 172.16.101.2: icmp_seq=6 ttl=64 time=11.8 ms 64 bytes from 172.16.101.2: icmp_seq=7 ttl=64 time=8.11 ms 64 bytes from 172.16.101.2: icmp_seq=8 ttl=64 time=10.0 ms 64 bytes from 172.16.101.2: icmp_seq=9 ttl=64 time=11.3 ms 64 bytes from 172.16.101.2: icmp_seq=10 ttl=64 time=11.5 ms 64 bytes from 172.16.101.2: icmp_seq=11 ttl=64 time=10.2 ms Reviewed-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-21net: sched: sch: add extack for graft callbackAlexander Aring1-1/+1
This patch adds extack support for graft callback to prepare per-qdisc specific changes for extack. Cc: David Ahern <dsahern@gmail.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Alexander Aring <aring@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-21net: sched: sch: add extack for change qdisc opsAlexander Aring1-2/+3
This patch adds extack support for change callback for qdisc ops structtur to prepare per-qdisc specific changes for extack. Cc: David Ahern <dsahern@gmail.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Alexander Aring <aring@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-21net: sched: sch: add extack for init callbackAlexander Aring1-1/+2
This patch adds extack support for init callback to prepare per-qdisc specific changes for extack. Cc: David Ahern <dsahern@gmail.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Alexander Aring <aring@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-15netem: remove unnecessary 64 bit modulusStephen Hemminger1-3/+3
Fix compilation on 32 bit platforms (where doing modulus operation with 64 bit requires extra glibc functions) by truncation. The jitter for table distribution is limited to a 32 bit value because random numbers are scaled as 32 bit value. Also fix some whitespace. Fixes: 99803171ef04 ("netem: add uapi to express delay and jitter in nanoseconds") Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-15netem: use 64 bit divide by rateStephen Hemminger1-7/+4
Since times are now expressed in nanosecond, need to now do true 64 bit divide. Old code would truncate rate at 32 bits. Rename function to better express current usage. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-13netem: support delivering packets in delayed time slotsDave Taht1-3/+71
Slotting is a crude approximation of the behaviors of shared media such as cable, wifi, and LTE, which gather up a bunch of packets within a varying delay window and deliver them, relative to that, nearly all at once. It works within the existing loss, duplication, jitter and delay parameters of netem. Some amount of inherent latency must be specified, regardless. The new "slot" parameter specifies a minimum and maximum delay between transmission attempts. The "bytes" and "packets" parameters can be used to limit the amount of information transferred per slot. Examples of use: tc qdisc add dev eth0 root netem delay 200us \ slot 800us 10ms bytes 64k packets 42 A more correct example, using stacked netem instances and a packet limit to emulate a tail drop wifi queue with slots and variable packet delivery, with a 200Mbit isochronous underlying rate, and 20ms path delay: tc qdisc add dev eth0 root handle 1: netem delay 20ms rate 200mbit \ limit 10000 tc qdisc add dev eth0 parent 1:1 handle 10:1 netem delay 200us \ slot 800us 10ms bytes 64k packets 42 limit 512 Signed-off-by: Dave Taht <dave.taht@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-13netem: add uapi to express delay and jitter in nanosecondsDave Taht1-0/+14
netem userspace has long relied on a horrible /proc/net/psched hack to translate the current notion of "ticks" to nanoseconds. Expressing latency and jitter instead, in well defined nanoseconds, increases the dynamic range of emulated delays and jitter in netem. It will also ease a transition where reducing a tick to nsec equivalence would constrain the max delay in prior versions of netem to only 4.3 seconds. Signed-off-by: Dave Taht <dave.taht@gmail.com> Suggested-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-13netem: convert to qdisc_watchdog_schedule_nsDave Taht1-28/+28
Upgrade the internal netem scheduler to use nanoseconds rather than ticks throughout. Convert to and from the std "ticks" userspace api automatically, while allowing for finer grained scheduling to take place. Signed-off-by: Dave Taht <dave.taht@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-07net: add rb_to_skb() and other rb tree helpersEric Dumazet1-10/+4
Geeralize private netem_rb_to_skb() TCP rtx queue will soon be converted to rb-tree, so we will need skb_rbtree_walk() helpers. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-25sch_netem: faster rb tree removalEric Dumazet1-3/+4
While running TCP tests involving netem storing millions of packets, I had the idea to speed up tfifo_reset() and did experiments. I tried the rbtree_postorder_for_each_entry_safe() method that is used in skb_rbtree_purge() but discovered it was slower than the current tfifo_reset() method. I measured time taken to release skbs with three occupation levels : 10^4, 10^5 and 10^6 skbs with three methods : 1) (current 'naive' method) while ((p = rb_first(&q->t_root))) { struct sk_buff *skb = netem_rb_to_skb(p); rb_erase(p, &q->t_root); rtnl_kfree_skbs(skb, skb); } 2) Use rb_next() instead of rb_first() in the loop : p = rb_first(&q->t_root); while (p) { struct sk_buff *skb = netem_rb_to_skb(p); p = rb_next(p); rb_erase(&skb->rbnode, &q->t_root); rtnl_kfree_skbs(skb, skb); } 3) "optimized" method using rbtree_postorder_for_each_entry_safe() struct sk_buff *skb, *next; rbtree_postorder_for_each_entry_safe(skb, next, &q->t_root, rbnode) { rtnl_kfree_skbs(skb, skb); } q->t_root = RB_ROOT; Results : method_1:while (rb_first()) rb_erase() 10000 skbs in 690378 ns (69 ns per skb) method_2:rb_first; while (p) { p = rb_next(p); ...} 10000 skbs in 541846 ns (54 ns per skb) method_3:rbtree_postorder_for_each_entry_safe() 10000 skbs in 868307 ns (86 ns per skb) method_1:while (rb_first()) rb_erase() 99996 skbs in 7804021 ns (78 ns per skb) method_2:rb_first; while (p) { p = rb_next(p); ...} 100000 skbs in 5942456 ns (59 ns per skb) method_3:rbtree_postorder_for_each_entry_safe() 100000 skbs in 11584940 ns (115 ns per skb) method_1:while (rb_first()) rb_erase() 1000000 skbs in 108577838 ns (108 ns per skb) method_2:rb_first; while (p) { p = rb_next(p); ...} 1000000 skbs in 82619635 ns (82 ns per skb) method_3:rbtree_postorder_for_each_entry_safe() 1000000 skbs in 127328743 ns (127 ns per skb) Method 2) is simply faster, probably because it maintains a smaller working size set. Note that this is the method we use in tcp_ofo_queue() already. I will also change skb_rbtree_purge() in a second patch. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-19net: sk_buff rbnode reorgEric Dumazet1-3/+4
skb->rbnode shares space with skb->next, skb->prev and skb->tstamp Current uses (TCP receive ofo queue and netem) need to save/restore tstamp, while skb->dev is either NULL (TCP) or a constant for a given queue (netem). Since we plan using an RB tree for TCP retransmit queue to speedup SACK processing with large BDP, this patch exchanges skb->dev and skb->tstamp. This saves some overhead in both TCP and netem. v2: removes the swtstamp field from struct tcp_skb_cb Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Soheil Hassas Yeganeh <soheil@google.com> Cc: Wei Wang <weiwan@google.com> Cc: Willem de Bruijn <willemb@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-2/+2
Three cases of simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-30sch_netem: avoid null pointer deref on init failureNikolay Aleksandrov1-2/+2
netem can fail in ->init due to missing options (either not supplied by user-space or used as a default qdisc) causing a timer->base null pointer deref in its ->destroy() and ->reset() callbacks. Reproduce: $ sysctl net.core.default_qdisc=netem $ ip l set ethX up Crash log: [ 1814.846943] BUG: unable to handle kernel NULL pointer dereference at (null) [ 1814.847181] IP: hrtimer_active+0x17/0x8a [ 1814.847270] PGD 59c34067 [ 1814.847271] P4D 59c34067 [ 1814.847337] PUD 37374067 [ 1814.847403] PMD 0 [ 1814.847468] [ 1814.847582] Oops: 0000 [#1] SMP [ 1814.847655] Modules linked in: sch_netem(O) sch_fq_codel(O) [ 1814.847761] CPU: 3 PID: 1573 Comm: ip Tainted: G O 4.13.0-rc6+ #62 [ 1814.847884] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [ 1814.848043] task: ffff88003723a700 task.stack: ffff88005adc8000 [ 1814.848235] RIP: 0010:hrtimer_active+0x17/0x8a [ 1814.848407] RSP: 0018:ffff88005adcb590 EFLAGS: 00010246 [ 1814.848590] RAX: 0000000000000000 RBX: ffff880058e359d8 RCX: 0000000000000000 [ 1814.848793] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880058e359d8 [ 1814.848998] RBP: ffff88005adcb5b0 R08: 00000000014080c0 R09: 00000000ffffffff [ 1814.849204] R10: ffff88005adcb660 R11: 0000000000000020 R12: 0000000000000000 [ 1814.849410] R13: ffff880058e359d8 R14: 00000000ffffffff R15: 0000000000000001 [ 1814.849616] FS: 00007f733bbca740(0000) GS:ffff88005d980000(0000) knlGS:0000000000000000 [ 1814.849919] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1814.850107] CR2: 0000000000000000 CR3: 0000000059f0d000 CR4: 00000000000406e0 [ 1814.850313] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1814.850518] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 1814.850723] Call Trace: [ 1814.850875] hrtimer_try_to_cancel+0x1a/0x93 [ 1814.851047] hrtimer_cancel+0x15/0x20 [ 1814.851211] qdisc_watchdog_cancel+0x12/0x14 [ 1814.851383] netem_reset+0xe6/0xed [sch_netem] [ 1814.851561] qdisc_destroy+0x8b/0xe5 [ 1814.851723] qdisc_create_dflt+0x86/0x94 [ 1814.851890] ? dev_activate+0x129/0x129 [ 1814.852057] attach_one_default_qdisc+0x36/0x63 [ 1814.852232] netdev_for_each_tx_queue+0x3d/0x48 [ 1814.852406] dev_activate+0x4b/0x129 [ 1814.852569] __dev_open+0xe7/0x104 [ 1814.852730] __dev_change_flags+0xc6/0x15c [ 1814.852899] dev_change_flags+0x25/0x59 [ 1814.853064] do_setlink+0x30c/0xb3f [ 1814.853228] ? check_chain_key+0xb0/0xfd [ 1814.853396] ? check_chain_key+0xb0/0xfd [ 1814.853565] rtnl_newlink+0x3a4/0x729 [ 1814.853728] ? rtnl_newlink+0x117/0x729 [ 1814.853905] ? ns_capable_common+0xd/0xb1 [ 1814.854072] ? ns_capable+0x13/0x15 [ 1814.854234] rtnetlink_rcv_msg+0x188/0x197 [ 1814.854404] ? rcu_read_unlock+0x3e/0x5f [ 1814.854572] ? rtnl_newlink+0x729/0x729 [ 1814.854737] netlink_rcv_skb+0x6c/0xce [ 1814.854902] rtnetlink_rcv+0x23/0x2a [ 1814.855064] netlink_unicast+0x103/0x181 [ 1814.855230] netlink_sendmsg+0x326/0x337 [ 1814.855398] sock_sendmsg_nosec+0x14/0x3f [ 1814.855584] sock_sendmsg+0x29/0x2e [ 1814.855747] ___sys_sendmsg+0x209/0x28b [ 1814.855912] ? do_raw_spin_unlock+0xcd/0xf8 [ 1814.856082] ? _raw_spin_unlock+0x27/0x31 [ 1814.856251] ? __handle_mm_fault+0x651/0xdb1 [ 1814.856421] ? check_chain_key+0xb0/0xfd [ 1814.856592] __sys_sendmsg+0x45/0x63 [ 1814.856755] ? __sys_sendmsg+0x45/0x63 [ 1814.856923] SyS_sendmsg+0x19/0x1b [ 1814.857083] entry_SYSCALL_64_fastpath+0x23/0xc2 [ 1814.857256] RIP: 0033:0x7f733b2dd690 [ 1814.857419] RSP: 002b:00007ffe1d3387d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 1814.858238] RAX: ffffffffffffffda RBX: ffffffff810d278c RCX: 00007f733b2dd690 [ 1814.858445] RDX: 0000000000000000 RSI: 00007ffe1d338820 RDI: 0000000000000003 [ 1814.858651] RBP: ffff88005adcbf98 R08: 0000000000000001 R09: 0000000000000003 [ 1814.858856] R10: 00007ffe1d3385a0 R11: 0000000000000246 R12: 0000000000000002 [ 1814.859060] R13: 000000000066f1a0 R14: 00007ffe1d3408d0 R15: 0000000000000000 [ 1814.859267] ? trace_hardirqs_off_caller+0xa7/0xcf [ 1814.859446] Code: 10 55 48 89 c7 48 89 e5 e8 45 a1 fb ff 31 c0 5d c3 31 c0 c3 66 66 66 66 90 55 48 89 e5 41 56 41 55 41 54 53 49 89 fd 49 8b 45 30 <4c> 8b 20 41 8b 5c 24 38 31 c9 31 d2 48 c7 c7 50 8e 1d 82 41 89 [ 1814.860022] RIP: hrtimer_active+0x17/0x8a RSP: ffff88005adcb590 [ 1814.860214] CR2: 0000000000000000 Fixes: 87b60cfacf9f ("net_sched: fix error recovery at qdisc creation") Fixes: 0fbbeb1ba43b ("[PKT_SCHED]: Fix missing qdisc_destroy() in qdisc_create_dflt()") Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25net_sched: remove tc class reference countingWANG Cong1-7/+2
For TC classes, their ->get() and ->put() are always paired, and the reference counting is completely useless, because: 1) For class modification and dumping paths, we already hold RTNL lock, so all of these ->get(),->change(),->put() are atomic. 2) For filter bindiing/unbinding, we use other reference counter than this one, and they should have RTNL lock too. 3) For ->qlen_notify(), it is special because it is called on ->enqueue() path, but we already hold qdisc tree lock there, and we hold this tree lock when graft or delete the class too, so it should not be gone or changed until we release the tree lock. Therefore, this patch removes ->get() and ->put(), but: 1) Adds a new ->find() to find the pointer to a class by classid, no refcnt. 2) Move the original class destroy upon the last refcnt into ->delete(), right after releasing tree lock. This is fine because the class is already removed from hash when holding the lock. For those who also use ->put() as ->unbind(), just rename them to reflect this change. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-08treewide: use kv[mz]alloc* rather than opencoded variantsMichal Hocko1-5/+1
There are many code paths opencoding kvmalloc. Let's use the helper instead. The main difference to kvmalloc is that those users are usually not considering all the aspects of the memory allocator. E.g. allocation requests <= 32kB (with 4kB pages) are basically never failing and invoke OOM killer to satisfy the allocation. This sounds too disruptive for something that has a reasonable fallback - the vmalloc. On the other hand those requests might fallback to vmalloc even when the memory allocator would succeed after several more reclaim/compaction attempts previously. There is no guarantee something like that happens though. This patch converts many of those places to kv[mz]alloc* helpers because they are more conservative. Link: http://lkml.kernel.org/r/20170306103327.2766-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> # Xen bits Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Andreas Dilger <andreas.dilger@intel.com> # Lustre Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> # KVM/s390 Acked-by: Dan Williams <dan.j.williams@intel.com> # nvdim Acked-by: David Sterba <dsterba@suse.com> # btrfs Acked-by: Ilya Dryomov <idryomov@gmail.com> # Ceph Acked-by: Tariq Toukan <tariqt@mellanox.com> # mlx4 Acked-by: Leon Romanovsky <leonro@mellanox.com> # mlx5 Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Tony Luck <tony.luck@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Santosh Raspatur <santosh@chelsio.com> Cc: Hariprasad S <hariprasad@chelsio.com> Cc: Yishai Hadas <yishaih@mellanox.com> Cc: Oleg Drokin <oleg.drokin@intel.com> Cc: "Yan, Zheng" <zyan@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-04-13netlink: pass extended ACK struct to parsing functionsJohannes Berg1-1/+1
Pass the new extended ACK reporting struct to all of the generic netlink parsing functions. For now, pass NULL in almost all callers (except for some in the core.) Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-16netem: apply correct delay when rate throttlingNik Unger1-8/+18
I recently reported on the netem list that iperf network benchmarks show unexpected results when a bandwidth throttling rate has been configured for netem. Specifically: 1) The measured link bandwidth *increases* when a higher delay is added 2) The measured link bandwidth appears higher than the specified limit 3) The measured link bandwidth for the same very slow settings varies significantly across machines The issue can be reproduced by using tc to configure netem with a 512kbit rate and various (none, 1us, 50ms, 100ms, 200ms) delays on a veth pair between network namespaces, and then using iperf (or any other network benchmarking tool) to test throughput. Complete detailed instructions are in the original email chain here: https://lists.linuxfoundation.org/pipermail/netem/2017-February/001672.html There appear to be two underlying bugs causing these effects: - The first issue causes long delays when the rate is slow and no delay is configured (e.g., "rate 512kbit"). This is because SKBs are not orphaned when no delay is configured, so orphaning does not occur until *after* the rate-induced delay has been applied. For this reason, adding a tiny delay (e.g., "rate 512kbit delay 1us") dramatically increases the measured bandwidth. - The second issue is that rate-induced delays are not correctly applied, allowing SKB delays to occur in parallel. The indended approach is to compute the delay for an SKB and to add this delay to the end of the current queue. However, the code does not detect existing SKBs in the queue due to improperly testing sch->q.qlen, which is nonzero even when packets exist only in the rbtree. Consequently, new SKBs do not wait for the current queue to empty. When packet delays vary significantly (e.g., if packet sizes are different), then this also causes unintended reordering. I modified the code to expect a delay (and orphan the SKB) when a rate is configured. I also added some defensive tests that correctly find the latest scheduled delivery time, even if it is (unexpectedly) for a packet in sch->q. I have tested these changes on the latest kernel (4.11.0-rc1+) and the iperf / ping test results are as expected. Signed-off-by: Nik Unger <njunger@uwaterloo.ca> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-08net-tc: convert tc_from to tc_from_ingress and tc_redirectedWillem de Bruijn1-1/+1
The tc_from field fulfills two roles. It encodes whether a packet was redirected by an act_mirred device and, if so, whether act_mirred was called on ingress or egress. Split it into separate fields. The information is needed by the special IFB loop, where packets are taken out of the normal path by act_mirred, forwarded to IFB, then reinjected at their original location (ingress or egress) by IFB. The IFB device cannot use skb->tc_at_ingress, because that may have been overwritten as the packet travels from act_mirred to ifb_xmit, when it passes through tc_classify on the IFB egress path. Cache this value in skb->tc_from_ingress. That field is valid only if a packet arriving at ifb_xmit came from act_mirred. Other packets can be crafted to reach ifb_xmit. These must be dropped. Set tc_redirected on redirection and drop all packets that do not have this bit set. Both fields are set only on cloned skbs in tc actions, so original packet sources do not have to clear the bit when reusing packets (notably, pktgen and octeon). Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-08net-tc: convert tc_verd to integer bitfieldsWillem de Bruijn1-1/+1
Extract the remaining two fields from tc_verd and remove the __u16 completely. TC_AT and TC_FROM are converted to equivalent two-bit integer fields tc_at and tc_from. Where possible, use existing helper skb_at_tc_ingress when reading tc_at. Introduce helper skb_reset_tc to clear fields. Not documenting tc_from and tc_at, because they will be replaced with single bit fields in follow-on patches. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-25ktime: Get rid of the unionThomas Gleixner1-1/+1
ktime is a union because the initial implementation stored the time in scalar nanoseconds on 64 bit machine and in a endianess optimized timespec variant for 32bit machines. The Y2038 cleanup removed the timespec variant and switched everything to scalar nanoseconds. The union remained, but become completely pointless. Get rid of the union and just keep ktime_t as simple typedef of type s64. The conversion was done with coccinelle and some manual mopping up. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
2016-12-20net_sched: sch_netem: use rb_entry()Geliang Tang1-1/+1
To make the code clearer, use rb_entry() instead of container_of() to deal with rbtree. Signed-off-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-19sched: add and use qdisc_skb_head helpersFlorian Westphal1-2/+12
This change replaces sk_buff_head struct in Qdiscs with new qdisc_skb_head. Its similar to the skb_buff_head api, but does not use skb->prev pointers. Qdiscs will commonly enqueue at the tail of a list and dequeue at head. While skb_buff_head works fine for this, enqueue/dequeue needs to also adjust the prev pointer of next element. The ->prev pointer is not required for qdiscs so we can just leave it undefined and avoid one cacheline write access for en/dequeue. Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-19sched: replace __skb_dequeue with __qdisc_dequeue_headFlorian Westphal1-1/+1
After previous patch these functions are identical. Replace __skb_dequeue in qdiscs with __qdisc_dequeue_head. Next patch will then make __qdisc_dequeue_head handle single-linked list instead of strcut sk_buff_head argument. Doesn't change generated code. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-19sched: don't use skb queue helpersFlorian Westphal1-2/+2
A followup change will replace the sk_buff_head in the qdisc struct with a slightly different list. Use of the sk_buff_head helpers will thus cause compiler warnings. Open-code these accesses in an extra change to ease review. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-6/+6
Several cases of overlapping changes, except the packet scheduler conflicts which deal with the addition of the free list parameter to qdisc_enqueue(). Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-29net_sched: netem: do not call qdisc_drop() with a NULL skbEric Dumazet1-4/+8
If skb_unshare() fails, we call qdisc_drop() with a NULL skb, which is no longer supported. Fixes: 520ac30f4551 ("net_sched: drop packets after root qdisc lock is released") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-25net_sched: drop packets after root qdisc lock is releasedEric Dumazet1-10/+15
Qdisc performance suffers when packets are dropped at enqueue() time because drops (kfree_skb()) are done while qdisc lock is held, delaying a dequeue() draining the queue. Nominal throughput can be reduced by 50 % when this happens, at a time we would like the dequeue() to proceed as fast as possible. Even FQ is vulnerable to this problem, while one of FQ goals was to provide some flow isolation. This patch adds a 'struct sk_buff **to_free' parameter to all qdisc->enqueue(), and in qdisc_drop() helper. I measured a performance increase of up to 12 %, but this patch is a prereq so that future batches in enqueue() can fly. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-23netem: fix a use after freeEric Dumazet1-6/+6
If the packet was dropped by lower qdisc, then we must not access it later. Save qdisc_pkt_len(skb) in a temp variable. Fixes: 2ccccf5fb43f ("net_sched: update hierarchical backlog too") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: WANG Cong <xiyou.wangcong@gmail.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-15net_sched: sch_netem: defer skb freeingEric Dumazet1-3/+1
rtnl_kfree_skbs() can be used in tfifo_reset() It would be nice if we could iterate through rb tree instead of removing one skb at a time, and build a single skb chain. But this is left for a future patch. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-10net_sched: remove generic throttled managementEric Dumazet1-1/+0
__QDISC_STATE_THROTTLED bit manipulation is rather expensive for HTB and few others. I already removed it for sch_fq in commit f2600cf02b5b ("net: sched: avoid costly atomic operation in fq_dequeue()") and so far nobody complained. When one ore more packets are stuck in one or more throttled HTB class, a htb dequeue() performs two atomic operations to clear/set __QDISC_STATE_THROTTLED bit, while root qdisc lock is held. Removing this pair of atomic operations bring me a 8 % performance increase on 200 TCP_RR tests, in presence of throttled classes. This patch has no side effect, since nothing actually uses disc_is_throttled() anymore. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-10net_sched: netem: remove qdisc_is_throttled() useEric Dumazet1-3/+0
Looks like it is only there as some optimization attempt. Since __QDISC_STATE_THROTTLED set/unset is way too expensive, and netem is the last user, just remove this check. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-08sched: remove qdisc->dropFlorian Westphal1-30/+0
after removal of TCA_CBQ_OVL_STRATEGY from cbq scheduler, there are no more callers of ->drop() outside of other ->drop functions, i.e. nothing calls them. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-08sched: remove qdisc_rehape_failFlorian Westphal1-2/+2
After the removal of TCA_CBQ_POLICE in cbq scheduler qdisc->reshape_fail is always NULL, i.e. qdisc_rehape_fail is now the same as qdisc_drop. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-2/+59
Conflicts: net/ipv4/ip_gre.c Minor conflicts between tunnel bug fixes in net and ipv6 tunnel cleanups in net-next. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-03netem: Segment GSO packets on enqueueNeil Horman1-2/+59
This was recently reported to me, and reproduced on the latest net kernel, when attempting to run netperf from a host that had a netem qdisc attached to the egress interface: [ 788.073771] ---------------------[ cut here ]--------------------------- [ 788.096716] WARNING: at net/core/dev.c:2253 skb_warn_bad_offload+0xcd/0xda() [ 788.129521] bnx2: caps=(0x00000001801949b3, 0x0000000000000000) len=2962 data_len=0 gso_size=1448 gso_type=1 ip_summed=3 [ 788.182150] Modules linked in: sch_netem kvm_amd kvm crc32_pclmul ipmi_ssif ghash_clmulni_intel sp5100_tco amd64_edac_mod aesni_intel lrw gf128mul glue_helper ablk_helper edac_mce_amd cryptd pcspkr sg edac_core hpilo ipmi_si i2c_piix4 k10temp fam15h_power hpwdt ipmi_msghandler shpchp acpi_power_meter pcc_cpufreq nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c sd_mod crc_t10dif crct10dif_generic mgag200 syscopyarea sysfillrect sysimgblt i2c_algo_bit drm_kms_helper ahci ata_generic pata_acpi ttm libahci crct10dif_pclmul pata_atiixp tg3 libata crct10dif_common drm crc32c_intel ptp serio_raw bnx2 r8169 hpsa pps_core i2c_core mii dm_mirror dm_region_hash dm_log dm_mod [ 788.465294] CPU: 16 PID: 0 Comm: swapper/16 Tainted: G W ------------ 3.10.0-327.el7.x86_64 #1 [ 788.511521] Hardware name: HP ProLiant DL385p Gen8, BIOS A28 12/17/2012 [ 788.542260] ffff880437c036b8 f7afc56532a53db9 ffff880437c03670 ffffffff816351f1 [ 788.576332] ffff880437c036a8 ffffffff8107b200 ffff880633e74200 ffff880231674000 [ 788.611943] 0000000000000001 0000000000000003 0000000000000000 ffff880437c03710 [ 788.647241] Call Trace: [ 788.658817] <IRQ> [<ffffffff816351f1>] dump_stack+0x19/0x1b [ 788.686193] [<ffffffff8107b200>] warn_slowpath_common+0x70/0xb0 [ 788.713803] [<ffffffff8107b29c>] warn_slowpath_fmt+0x5c/0x80 [ 788.741314] [<ffffffff812f92f3>] ? ___ratelimit+0x93/0x100 [ 788.767018] [<ffffffff81637f49>] skb_warn_bad_offload+0xcd/0xda [ 788.796117] [<ffffffff8152950c>] skb_checksum_help+0x17c/0x190 [ 788.823392] [<ffffffffa01463a1>] netem_enqueue+0x741/0x7c0 [sch_netem] [ 788.854487] [<ffffffff8152cb58>] dev_queue_xmit+0x2a8/0x570 [ 788.880870] [<ffffffff8156ae1d>] ip_finish_output+0x53d/0x7d0 ... The problem occurs because netem is not prepared to handle GSO packets (as it uses skb_checksum_help in its enqueue path, which cannot manipulate these frames). The solution I think is to simply segment the skb in a simmilar fashion to the way we do in __dev_queue_xmit (via validate_xmit_skb), with some minor changes. When we decide to corrupt an skb, if the frame is GSO, we segment it, corrupt the first segment, and enqueue the remaining ones. tested successfully by myself on the latest net kernel, to which this applies Signed-off-by: Neil Horman <nhorman@tuxdriver.com> CC: Jamal Hadi Salim <jhs@mojatatu.com> CC: "David S. Miller" <davem@davemloft.net> CC: netem@lists.linux-foundation.org CC: eric.dumazet@gmail.com CC: stephen@networkplumber.org Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-25sched: use nla_put_u64_64bit()Nicolas Dichtel1-1/+2
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-29net_sched: update hierarchical backlog tooWANG Cong1-1/+2
When the bottom qdisc decides to, for example, drop some packet, it calls qdisc_tree_decrease_qlen() to update the queue length for all its ancestors, we need to update the backlog too to keep the stats on root qdisc accurate. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-29net_sched: introduce qdisc_replace() helperWANG Cong1-9/+1
Remove nearly duplicated code and prepare for the following patch. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11net: sched: deprecate enqueue_root()Eric Dumazet1-2/+2
Only left enqueue_root() user is netem, and it looks not necessary : qdisc_skb_cb(skb)->pkt_len is preserved after one skb_clone() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-07netem: Fixes byte backlog accounting for the first of two chained netem instancesBeshay, Joseph1-1/+2
Fixes byte backlog accounting for the first of two chained netem instances. Bytes backlog reported now corresponds to the number of queued packets. When two netem instances are chained, for instance to apply rate and queue limitation followed by packet delay, the number of backlogged bytes reported by the first netem instance is wrong. It reports the sum of bytes in the queues of the first and second netem. The first netem reports the correct number of backlogged packets but not bytes. This is shown in the example below. Consider a chain of two netem schedulers created using the following commands: $ tc -s qdisc replace dev veth2 root handle 1:0 netem rate 10000kbit limit 100 $ tc -s qdisc add dev veth2 parent 1:0 handle 2: netem delay 50ms Start an iperf session to send packets out on the specified interface and monitor the backlog using tc: $ tc -s qdisc show dev veth2 Output using unpatched netem: qdisc netem 1: root refcnt 2 limit 100 rate 10000Kbit Sent 98422639 bytes 65434 pkt (dropped 123, overlimits 0 requeues 0) backlog 172694b 73p requeues 0 qdisc netem 2: parent 1: limit 1000 delay 50.0ms Sent 98422639 bytes 65434 pkt (dropped 0, overlimits 0 requeues 0) backlog 63588b 42p requeues 0 The interface used to produce this output has an MTU of 1500. The output for backlogged bytes behind netem 1 is 172694b. This value is not correct. Consider the total number of sent bytes and packets. By dividing the number of sent bytes by the number of sent packets, we get an average packet size of ~=1504. If we divide the number of backlogged bytes by packets, we get ~=2365. This is due to the first netem incorrectly counting the 63588b which are in netem 2's queue as being in its own queue. To verify this is the case, we subtract them from the reported value and divide by the number of packets as follows: 172694 - 63588 = 109106 bytes actualled backlogged in netem 1 109106 / 73 packets ~= 1494 bytes (which matches our MTU) The root cause is that the byte accounting is not done at the same time with packet accounting. The solution is to update the backlog value every time the packet queue is updated. Signed-off-by: Joseph D Beshay <joseph.beshay@utdallas.edu> Acked-by: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-03net: add rbnode to struct sk_buffEric Dumazet1-20/+7
Yaogong replaces TCP out of order receive queue by an RB tree. As netem already does a private skb->{next/prev/tstamp} union with a 'struct rb_node', lets do this in a cleaner way. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Yaogong Wang <wygivan@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-30net: sched: implement qstat helper routinesJohn Fastabend1-8/+7
This adds helpers to manipulate qstats logic and replaces locations that touch the counters directly. This simplifies future patches to push qstats onto per cpu counters. Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-05net: use the new API kvfree()WANG Cong1-6/+1
It is available since v3.15-rc5. Cc: Pablo Neira Ayuso <pablo@netfilter.org> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-17sch_netem: replace magic numbers with enumerate in get_loss_clgYang Yingliang1-2/+2
Replace two magic numbers which intialize clgstate::state. Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-14sch_netem: replace magic numbers with enumerate in GE modelYang Yingliang1-4/+9
Replace some magic numbers which describe states of GE model loss generator with enumerate. Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-14sch_netem: change some func's param from "struct Qdisc *" to "struct netem_sched_data *"Yang Yingliang1-15/+10
In netem_change(), we have already get "struct netem_sched_data *q". Replace params of get_correlation() and other similar functions with "struct netem_sched_data *q". Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-14sch_netem: return errcode before setting paramsYang Yingliang1-10/+29
get_dist_table() and get_loss_clg() may be failed. These two functions should be called after setting the members of qdisc_priv(sch), or it will break the old settings while either of them is failed. Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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