kernel.git/include/trace/events/qdisc.h, branch linux-6.8.y

tracing/net_sched: Fix tracepoints that save qdisc_dev() as a string

2024-03-04T09:35:54Z

I'm updating __assign_str() and will be removing the second parameter. To make sure that it does not break anything, I make sure that it matches the __string() field, as that is where the string is actually going to be saved in. To make sure there's nothing that breaks, I added a WARN_ON() to make sure that what was used in __string() is the same that is used in __assign_str(). In doing this change, an error was triggered as __assign_str() now expects the string passed in to be a char * value. I instead had the following warning: include/trace/events/qdisc.h: In function ‘trace_event_raw_event_qdisc_reset’: include/trace/events/qdisc.h:91:35: error: passing argument 1 of 'strcmp' from incompatible pointer type [-Werror=incompatible-pointer-types] 91 | __assign_str(dev, qdisc_dev(q)); That's because the qdisc_enqueue() and qdisc_reset() pass in qdisc_dev(q) to __assign_str() and to __string(). But that function returns a pointer to struct net_device and not a string. It appears that these events are just saving the pointer as a string and then reading it as a string as well. Use qdisc_dev(q)->name to save the device instead. Fixes: a34dac0b90552 ("net_sched: add tracepoints for qdisc_reset() and qdisc_destroy()") Signed-off-by: Steven Rostedt (Google) Reviewed-by: Jamal Hadi Salim Signed-off-by: David S. Miller

net: Print hashed skb addresses for all net and qdisc events

2022-06-27T10:57:06Z

The following commits added support for printing the real address- 65875073eddd ("net: use %px to print skb address in trace_netif_receive_skb") 70713dddf3d2 ("net_sched: introduce tracepoint trace_qdisc_enqueue()") 851f36e40962 ("net_sched: use %px to print skb address in trace_qdisc_dequeue()") However, tracing the packet traversal shows a mix of hashes and real addresses. Pasting a sample trace for reference- ping-14249 [002] ..... 3424.046612: netif_rx_entry: dev=lo napi_id=0x3 queue_mapping=0 skbaddr=00000000dcbed83e vlan_tagged=0 vlan_proto=0x0000 vlan_tci=0x0000 protocol=0x0800 ip_summed=0 hash=0x00000000 l4_hash=0 len=84 data_len=0 truesize=768 mac_header_valid=1 mac_header=-14 nr_frags=0 gso_size=0 gso_type=0x0 ping-14249 [002] ..... 3424.046615: netif_rx: dev=lo skbaddr=ffffff888e5d1000 len=84 Switch the trace print formats to %p for all the events to have a consistent format of printing the hashed addresses in all cases. Signed-off-by: Sean Tranchetti Signed-off-by: Subash Abhinov Kasiviswanathan Signed-off-by: David S. Miller

qdisc: add new field for qdisc_enqueue tracepoint

2021-07-27T13:16:38Z

qdisc_enqueue tracepoint can work with qdisc:qdisc_dequeue to measure packets latency in qdisc queues. Add a new field txq for it, then we can retrieve more info. Signed-off-by: Tonghao Zhang Signed-off-by: David S. Miller

net_sched: introduce tracepoint trace_qdisc_enqueue()

2021-07-15T17:32:38Z

Tracepoint trace_qdisc_enqueue() is introduced to trace skb at the entrance of TC layer on TX side. This is similar to trace_qdisc_dequeue(): 1. For both we only trace successful cases. The failure cases can be traced via trace_kfree_skb(). 2. They are called at entrance or exit of TC layer, not for each ->enqueue() or ->dequeue(). This is intentional, because we want to make trace_qdisc_enqueue() symmetric to trace_qdisc_dequeue(), which is easier to use. The return value of qdisc_enqueue() is not interesting here, we have Qdisc's drop packets in ->dequeue(), it is impossible to trace them even if we have the return value, the only way to trace them is tracing kfree_skb(). We only add information we need to trace ring buffer. If any other information is needed, it is easy to extend it without breaking ABI, see commit 3dd344ea84e1 ("net: tracepoint: exposing sk_family in all tcp:tracepoints"). Reviewed-by: Cong Wang Signed-off-by: Qitao Xu Signed-off-by: David S. Miller

net_sched: use %px to print skb address in trace_qdisc_dequeue()

2021-07-15T17:31:23Z

Print format of skbaddr is changed to %px from %p, because we want to use skb address as a quick way to identify a packet. Note, trace ring buffer is only accessible to privileged users, it is safe to use a real kernel address here. Reviewed-by: Cong Wang Signed-off-by: Qitao Xu Signed-off-by: David S. Miller

net_sched: add a tracepoint for qdisc creation

2020-05-27T22:05:49Z

With this tracepoint, we could know when qdisc's are created, especially those default qdisc's. Sample output: tc-736 [001] ...1 56.230107: qdisc_create: dev=ens3 kind=pfifo parent=1:0 tc-736 [001] ...1 56.230113: qdisc_create: dev=ens3 kind=hfsc parent=ffff:ffff tc-738 [001] ...1 56.256816: qdisc_create: dev=ens3 kind=pfifo parent=1:100 tc-739 [001] ...1 56.267584: qdisc_create: dev=ens3 kind=pfifo parent=1:200 tc-740 [001] ...1 56.279649: qdisc_create: dev=ens3 kind=fq_codel parent=1:100 tc-741 [001] ...1 56.289996: qdisc_create: dev=ens3 kind=pfifo_fast parent=1:200 tc-745 [000] .N.1 111.687483: qdisc_create: dev=ens3 kind=ingress parent=ffff:fff1 Cc: Jamal Hadi Salim Cc: Jiri Pirko Signed-off-by: Cong Wang Signed-off-by: David S. Miller

net_sched: add tracepoints for qdisc_reset() and qdisc_destroy()

2020-05-27T22:05:49Z

Add two tracepoints for qdisc_reset() and qdisc_destroy() to track qdisc resetting and destroying. Sample output: tc-756 [000] ...3 138.355662: qdisc_reset: dev=ens3 kind=pfifo_fast parent=ffff:ffff handle=0:0 tc-756 [000] ...1 138.355720: qdisc_reset: dev=ens3 kind=pfifo_fast parent=ffff:ffff handle=0:0 tc-756 [000] ...1 138.355867: qdisc_reset: dev=ens3 kind=pfifo_fast parent=ffff:ffff handle=0:0 tc-756 [000] ...1 138.355930: qdisc_destroy: dev=ens3 kind=pfifo_fast parent=ffff:ffff handle=0:0 tc-757 [000] ...2 143.073780: qdisc_reset: dev=ens3 kind=fq_codel parent=ffff:ffff handle=8001:0 tc-757 [000] ...1 143.073878: qdisc_reset: dev=ens3 kind=fq_codel parent=ffff:ffff handle=8001:0 tc-757 [000] ...1 143.074114: qdisc_reset: dev=ens3 kind=fq_codel parent=ffff:ffff handle=8001:0 tc-757 [000] ...1 143.074228: qdisc_destroy: dev=ens3 kind=fq_codel parent=ffff:ffff handle=8001:0 Cc: Jamal Hadi Salim Cc: Jiri Pirko Signed-off-by: Cong Wang Signed-off-by: David S. Miller

tracing: Fix header include guards in trace event headers

2019-07-31T01:49:06Z

These include guards are broken. Match the #if !define() and #define lines so that they work correctly. Link: http://lkml.kernel.org/r/20190720103943.16982-1-yamada.masahiro@socionext.com Fixes: f54d1867005c3 ("dma-buf: Rename struct fence to dma_fence") Fixes: 2e26ca7150a4f ("tracing: Fix tracepoint.h DECLARE_TRACE() to allow more than one header") Fixes: e543002f77f46 ("qdisc: add tracepoint qdisc:qdisc_dequeue for dequeued SKBs") Fixes: 95f295f9fe081 ("dmaengine: tegra: add tracepoints to driver") Signed-off-by: Masahiro Yamada Signed-off-by: Steven Rostedt (VMware)

qdisc: add tracepoint qdisc:qdisc_dequeue for dequeued SKBs

2017-08-16T21:10:10Z

The main purpose of this tracepoint is to monitor bulk dequeue in the network qdisc layer, as it cannot be deducted from the existing qdisc stats. The txq_state can be used for determining the reason for zero packet dequeues, see enum netdev_queue_state_t. Notice all packets doesn't necessary activate this tracepoint. As qdiscs with flag TCQ_F_CAN_BYPASS, can directly invoke sch_direct_xmit() when qdisc_qlen is zero. Remember that perf record supports filters like: perf record -e qdisc:qdisc_dequeue \ --filter 'ifindex == 4 && (packets > 1 || txq_state > 0)' Signed-off-by: Jesper Dangaard Brouer Signed-off-by: David S. Miller