Re: Network latency on 5.4 and 5.10

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



hi Christoph,

what's your command to get this log? it seems to have better information than mine.

Is it "trace-cmd start -e all -p function -l "kmem""? would you mind to share yours, many thanks.

BR

Song

在 2021/5/25 下午10:30, Christoph Mathys 写道:
I did some more testing on 5.10 and it seems my
network irq thread runs into some kind of PI with
the RCU thread and thus cannot run for ~200us.

Some questions:
  - Why does this PI happen?
  - Can I avoid it? How?
  - Can I avoid that the RCU runs for such a long
    time at once?

I'm playing around with NOHZ_FULL and RCU callback
offloading at the moment to see if this helps somehow.
But with only two cores my options on juggling
threads onto CPUs are somewhat limited.


          rcuc/1-20      [001] .....12 16017.277265: kmem_cache_free: call_site=rcu_do_batch+0x194/0x480 ptr=000000000c04e43c           rcuc/1-20      [001] .....12 16017.277265: kmem_cache_free: call_site=rcu_do_batch+0x194/0x480 ptr=00000000c6b95ab2           rcuc/1-20      [001] .....12 16017.277266: kmem_cache_free: call_site=rcu_do_batch+0x194/0x480 ptr=00000000f9863725           rcuc/1-20      [001] d..h212 16017.277266: irq_handler_entry: irq=130 name=ecat0-rx-0           rcuc/1-20      [001] d..h212 16017.277266: irq_handler_exit: irq=130 ret=handled           rcuc/1-20      [001] d..h412 16017.277266: sched_waking: comm=irq/130-ecat0-r pid=25665 prio=19 target_cpu=001           rcuc/1-20      [001] dN.h512 16017.277267: sched_wakeup: comm=irq/130-ecat0-r pid=25665 prio=19 target_cpu=001           rcuc/1-20      [001] dN..112 16017.277267: rcu_utilization: Start context switch           rcuc/1-20      [001] dN..112 16017.277267: rcu_utilization: End context switch           rcuc/1-20      [001] d...212 16017.277268: sched_switch: prev_comm=rcuc/1 prev_pid=20 prev_prio=98 prev_state=R+ ==> next_comm=irq/130-ecat0-r next_pid=25665 next_prio=19  irq/130-ecat0-r-25665   [001] d...311 16017.277269: sched_pi_setprio: comm=rcuc/1 pid=20 oldprio=98 newprio=19  irq/130-ecat0-r-25665   [001] d...111 16017.277270: rcu_utilization: Start context switch  irq/130-ecat0-r-25665   [001] d...111 16017.277270: rcu_utilization: End context switch  irq/130-ecat0-r-25665   [001] d...211 16017.277270: sched_switch: prev_comm=irq/130-ecat0-r prev_pid=25665 prev_prio=19 prev_state=R+ ==> next_comm=rcuc/1 next_pid=20 next_prio=19           rcuc/1-20      [001] .....12 16017.277271: kmem_cache_free: call_site=rcu_do_batch+0x194/0x480 ptr=000000008900a49c
<lots of similar lines>
          rcuc/1-20      [001] d...112 16017.277288: workqueue_queue_work: work struct=0000000093763c71 function=css_killed_work_fn workqueue=0000000040d70e90 req_cpu=16 cpu=1           rcuc/1-20      [001] d...112 16017.277289: workqueue_activate_work: work struct 0000000093763c71           rcuc/1-20      [001] d...312 16017.277289: sched_waking: comm=kworker/1:2 pid=13240 prio=120 target_cpu=001           rcuc/1-20      [001] d...412 16017.277290: sched_wakeup: comm=kworker/1:2 pid=13240 prio=120 target_cpu=001           rcuc/1-20      [001] .....13 16017.277290: percpu_free_percpu: base_addr=0000000026e5557e off=111288 ptr=00000000cb224c7a           rcuc/1-20      [001] .....13 16017.277290: percpu_free_percpu: base_addr=0000000026e5557e off=111280 ptr=000000001ea01103           rcuc/1-20      [001] .....12 16017.277290: kmem_cache_free: call_site=rcu_do_batch+0x194/0x480 ptr=00000000f7fe2da7
<lots of similar lines>
          rcuc/1-20      [001] .....12 16017.277299: kmem_cache_free: call_site=rcu_do_batch+0x194/0x480 ptr=000000004363b5fd           rcuc/1-20      [001] d..h212 16017.277300: local_timer_entry: vector=236           rcuc/1-20      [001] d..h312 16017.277300: softirq_raise: vec=8 [action=HRTIMER]           rcuc/1-20      [001] d..h212 16017.277300: write_msr: 6e0, value 304f993b507a           rcuc/1-20      [001] d..h212 16017.277300: local_timer_exit: vector=236           rcuc/1-20      [001] .....12 16017.277301: kmem_cache_free: call_site=rcu_do_batch+0x194/0x480 ptr=00000000407b3531
<lots of similar lines>
          rcuc/1-20      [001] .....12 16017.277305: kmem_cache_free: call_site=rcu_do_batch+0x194/0x480 ptr=00000000af2cd46f           rcuc/1-20      [001] d..h.12 16017.277305: local_timer_entry: vector=236           rcuc/1-20      [001] d..h112 16017.277306: hrtimer_cancel: hrtimer=0000000082cde4bc           rcuc/1-20      [001] d..h.12 16017.277306: hrtimer_expire_entry: hrtimer=0000000082cde4bc function=hrtimer_wakeup now=16017273215561           rcuc/1-20      [001] d..h212 16017.277306: sched_waking: comm=cyclictest pid=20680 prio=19 target_cpu=001           rcuc/1-20      [001] d..h312 16017.277306: sched_wakeup: comm=cyclictest pid=20680 prio=19 target_cpu=001           rcuc/1-20      [001] d..h.12 16017.277307: hrtimer_expire_exit: hrtimer=0000000082cde4bc           rcuc/1-20      [001] d..h.12 16017.277307: write_msr: 6e0, value 304f996a73c6           rcuc/1-20      [001] d..h.12 16017.277307: local_timer_exit: vector=236           rcuc/1-20      [001] .....12 16017.277307: kmem_cache_free: call_site=rcu_do_batch+0x194/0x480 ptr=000000008da0302a
<lots of similar lines>
          rcuc/1-20      [001] .....12 16017.277418: kmem_cache_free: call_site=rcu_do_batch+0x194/0x480 ptr=00000000994b1e7d           rcuc/1-20      [001] .....12 16017.277418: mm_page_free: page=00000000a7e4a633 pfn=104560 order=2           rcuc/1-20      [001] .....12 16017.277418: kmem_cache_free: call_site=rcu_do_batch+0x194/0x480 ptr=0000000054b769bf           rcuc/1-20      [001] .....12 16017.277419: sched_process_free: comm=kill pid=14926 prio=120           rcuc/1-20      [001] d...113 16017.277421: workqueue_queue_work: work struct=00000000d2b86e8a function=css_release_work_fn workqueue=0000000040d70e90 req_cpu=16 cpu=1           rcuc/1-20      [001] .....13 16017.277421: kfree: call_site=put_css_set_locked+0x155/0x2b0 ptr=000000000b628ae9           rcuc/1-20      [001] d...113 16017.277422: workqueue_queue_work: work struct=00000000d6255bb4 function=css_release_work_fn workqueue=0000000040d70e90 req_cpu=16 cpu=1           rcuc/1-20      [001] .....13 16017.277422: kfree: call_site=put_css_set_locked+0x155/0x2b0 ptr=00000000d844ad24           rcuc/1-20      [001] .....13 16017.277422: kfree: call_site=put_css_set_locked+0x155/0x2b0 ptr=00000000a49f8139           rcuc/1-20      [001] .....13 16017.277422: kfree: call_site=put_css_set_locked+0x155/0x2b0 ptr=00000000f2b3224d           rcuc/1-20      [001] .....13 16017.277422: kfree: call_site=put_css_set_locked+0x155/0x2b0 ptr=00000000d2397b3c           rcuc/1-20      [001] .....13 16017.277423: kfree: call_site=put_css_set_locked+0x155/0x2b0 ptr=00000000a367555e           rcuc/1-20      [001] .....13 16017.277423: kfree: call_site=put_css_set_locked+0x155/0x2b0 ptr=000000002aaa5cac           rcuc/1-20      [001] .....13 16017.277423: kfree: call_site=put_css_set_locked+0x155/0x2b0 ptr=00000000430e91ae           rcuc/1-20      [001] .....13 16017.277423: kfree: call_site=put_css_set_locked+0x155/0x2b0 ptr=00000000f8512c96           rcuc/1-20      [001] .....13 16017.277423: kfree: call_site=put_css_set_locked+0x155/0x2b0 ptr=000000005e5ac681           rcuc/1-20      [001] d...213 16017.277424: timer_start: timer=0000000098e46346 function=delayed_work_timer_fn expires=4310684537 [timeout=20] cpu=1 idx=58 flags=I           rcuc/1-20      [001] .....12 16017.277425: kfree: call_site=security_task_free+0x36/0x50 ptr=00000000e928d73e           rcuc/1-20      [001] .....12 16017.277425: kmem_cache_free: call_site=__put_task_struct+0x88/0x190 ptr=00000000d32d025d
<lots of similar lines>
          rcuc/1-20      [001] .....12 16017.277452: kmem_cache_free: call_site=rcu_do_batch+0x194/0x480 ptr=00000000097691fb           rcuc/1-20      [001] .....12 16017.277453: sched_process_free: comm=(sd-pam) pid=14847 prio=120           rcuc/1-20      [001] d...112 16017.277454: workqueue_queue_work: work struct=0000000077c15f97 function=free_work workqueue=00000000f605602a req_cpu=16 cpu=1           rcuc/1-20      [001] d...112 16017.277454: workqueue_activate_work: work struct 0000000077c15f97           rcuc/1-20      [001] .....12 16017.277454: kfree: call_site=security_task_free+0x36/0x50 ptr=000000003016d2cc           rcuc/1-20      [001] .....12 16017.277454: kmem_cache_free: call_site=__put_task_struct+0x88/0x190 ptr=000000008d44c92c           rcuc/1-20      [001] .....12 16017.277455: kmem_cache_free: call_site=__put_task_struct+0x101/0x190 ptr=00000000bf1f1ae9           rcuc/1-20      [001] .....12 16017.277455: kfree: call_site=free_task+0x1b/0x60 ptr=0000000000000000           rcuc/1-20      [001] .....12 16017.277455: kmem_cache_free: call_site=rcu_do_batch+0x194/0x480 ptr=00000000eb792cfc           rcuc/1-20      [001] .....12 16017.277456: sched_process_free: comm=systemd pid=14846 prio=120           rcuc/1-20      [001] d...113 16017.277457: workqueue_queue_work: work struct=00000000a65dcda5 function=css_release_work_fn workqueue=0000000040d70e90 req_cpu=16 cpu=1           rcuc/1-20      [001] .....13 16017.277457: kfree: call_site=put_css_set_locked+0x155/0x2b0 ptr=00000000a29d18ed           rcuc/1-20      [001] d...113 16017.277457: workqueue_queue_work: work struct=0000000000e1ccca function=css_release_work_fn workqueue=0000000040d70e90 req_cpu=16 cpu=1           rcuc/1-20      [001] .....13 16017.277457: kfree: call_site=put_css_set_locked+0x155/0x2b0 ptr=00000000cfeca6c9
<lots of similar lines>
          rcuc/1-20      [001] .....12 16017.277461: kmem_cache_free: call_site=rcu_do_batch+0x194/0x480 ptr=000000009e31b81e           rcuc/1-20      [001] .....12 16017.277461: rcu_utilization: End RCU core           rcuc/1-20      [001] ...s.12 16017.277462: softirq_entry: vec=8 [action=HRTIMER]           rcuc/1-20      [001] d..s113 16017.277462: hrtimer_cancel: hrtimer=000000009862add4           rcuc/1-20      [001] ...s.13 16017.277462: hrtimer_expire_entry: hrtimer=000000009862add4 function=hrtimer_wakeup now=16017273371650           rcuc/1-20      [001] d..s213 16017.277462: sched_waking: comm=EtherlabDaemon pid=25770 prio=120 target_cpu=001           rcuc/1-20      [001] d..s313 16017.277464: sched_wakeup: comm=EtherlabDaemon pid=25770 prio=120 target_cpu=001           rcuc/1-20      [001] ...s.13 16017.277464: hrtimer_expire_exit: hrtimer=000000009862add4           rcuc/1-20      [001] d..s113 16017.277464: write_msr: 6e0, value 304f994bc448           rcuc/1-20      [001] ...s.12 16017.277464: softirq_exit: vec=8 [action=HRTIMER]           rcuc/1-20      [001] dN..311 16017.277465: sched_pi_setprio: comm=rcuc/1 pid=20 oldprio=19 newprio=98           rcuc/1-20      [001] dN..311 16017.277466: sched_waking: comm=irq/130-ecat0-r pid=25665 prio=19 target_cpu=001           rcuc/1-20      [001] dN..411 16017.277466: sched_wakeup: comm=irq/130-ecat0-r pid=25665 prio=19 target_cpu=001           rcuc/1-20      [001] .N..... 16017.277467: rcu_utilization: End CPU kthread@rcu_wait           rcuc/1-20      [001] dN..1.. 16017.277467: rcu_utilization: Start context switch           rcuc/1-20      [001] dN..1.. 16017.277467: rcu_utilization: End context switch           rcuc/1-20      [001] d...2.. 16017.277468: sched_switch: prev_comm=rcuc/1 prev_pid=20 prev_prio=98 prev_state=R+ ==> next_comm=cyclictest next_pid=20680 next_prio=19           rcuc/1-20      [001] d...2.. 16017.277468: tlb_flush: pages:0 reason:flush on task switch (0)       cyclictest-20680   [001] ....1.. 16017.277469: sys_clock_nanosleep -> 0x0
       cyclictest-20680   [001] ....... 16017.277470: sys_exit: NR 230 = 0
      cyclictest-20680   [001] d...... 16017.277470: x86_fpu_regs_activated: x86/fpu: 000000001e825867 load: 1 xfeatures: 2 xcomp_bv: 8000000000000003       cyclictest-20680   [001] d..h... 16017.277474: call_function_single_entry: vector=251       cyclictest-20680   [001] d..h... 16017.277475: call_function_single_exit: vector=251       cyclictest-20680   [001] d..h... 16017.277476: irq_work_entry: vector=246       cyclictest-20680   [001] d..h2.. 16017.277479: sched_migrate_task: comm=EtherCATControl pid=25916 prio=20 orig_cpu=1 dest_cpu=0       cyclictest-20680   [001] d..h... 16017.277480: irq_work_exit: vector=246       cyclictest-20680   [001] ....1.. 16017.277485: sys_write(fd: 4, buf: 7f98e50e0300, count: 21)       cyclictest-20680   [001] ....... 16017.277485: sys_enter: NR 1 (4, 7f98e50e0300, 21, 0, 0, 0)       cyclictest-20680   [001] ....... 16017.277486: tracing_mark_write: hit latency threshold (165 > 150)
       cyclictest-20680   [001] ....1.. 16017.277487: sys_write -> 0x21
       cyclictest-20680   [001] ....... 16017.277487: sys_exit: NR 1 = 33
      cyclictest-20680   [001] ....1.. 16017.277487: sys_write(fd: 5, buf: 409a8a, count: 2)       cyclictest-20680   [001] ....... 16017.277487: sys_enter: NR 1 (5, 409a8a, 2, 0, 0, 0)




[Index of Archives]     [RT Stable]     [Kernel Newbies]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Samba]     [Video 4 Linux]     [Device Mapper]

  Powered by Linux