touch-packages team mailing list archive

[Colin Ian King <1364464@xxxxxxxxxxxxxxxxxx>]

Test scenario:

Clean install with developer mode so I can access the device via adb
shell.   Device is on the lock screen, sitting idle, so essentially is
should be doing not a lot.

I ran eventstat to see which processes are generating the most wakeups:

root@ubuntu-phablet:~# eventstat 60 1
 Event/s PID   Task            Init Function             Callback
   87.00     0 [swapper/0]     hrtimer_start_range_ns    tick_sched_timer
   39.05  3759 scopes_ng::Scop hrtimer_start_range_ns    hrtimer_wakeup
   16.68     5 [kworker/u:0]   hwmsen_work_func          hwmsen_poll
   10.00  3951 ubuntu-location hrtimer_start_range_ns    hrtimer_wakeup

Then I strace'd PID 3759, 
strace -p 3759 -e connect

-- 
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to unity-scopes-shell in
Ubuntu.
https://bugs.launchpad.net/bugs/1364464

Title:
  unity8-dash has a thread that is polling rather rapidly on epoll wait

Status in “unity-scopes-api” package in Ubuntu:
  New
Status in “unity-scopes-shell” package in Ubuntu:
  New
Status in “unity8” package in Ubuntu:
  Incomplete

Bug description:
  one of the threads to unity8-dash is creating quite a few wakeups per
  second:

  # eventstat 60 1

   Event/s PID   Task            Init Function             Callback
     13.02  2812 scopes_ng::Scop hrtimer_start_range_ns    hrtimer_wakeup

  process 2812 is a thread of unity8-dash

  attaching strace to the thread we see:

  root@ubuntu-phablet:/proc# strace -p 2812 
  Process 2812 attached
  clock_gettime(CLOCK_MONOTONIC, {925, 47970238}) = 0
  epoll_wait(57, {}, 256, 115)            = 0
  clock_gettime(CLOCK_MONOTONIC, {925, 165670469}) = 0
  socket(PF_LOCAL, SOCK_STREAM|SOCK_CLOEXEC, 0) = 50
  fcntl64(50, F_GETFL)                    = 0x2 (flags O_RDWR)
  fcntl64(50, F_SETFL, O_RDWR|O_NONBLOCK) = 0
  connect(50, {sa_family=AF_LOCAL, sun_path="/run/user/32011/zmq/priv/clickscope"}, 110) = -1 ENOENT (No such file or directory)
  close(50)                               = 0
  clock_gettime(CLOCK_MONOTONIC, {925, 174626930}) = 0
  epoll_wait(57, {}, 256, 39)             = 0
  clock_gettime(CLOCK_MONOTONIC, {925, 215561930}) = 0
  socket(PF_LOCAL, SOCK_STREAM|SOCK_CLOEXEC, 0) = 50
  fcntl64(50, F_GETFL)                    = 0x2 (flags O_RDWR)
  fcntl64(50, F_SETFL, O_RDWR|O_NONBLOCK) = 0
  connect(50, {sa_family=AF_LOCAL, sun_path="/run/user/32011/zmq/priv/clickscope"}, 110) = -1 ENOENT (No such file or directory)
  close(50)                               = 0
  clock_gettime(CLOCK_MONOTONIC, {925, 222932007}) = 0
  epoll_wait(57, {}, 256, 65)             = 0
  clock_gettime(CLOCK_MONOTONIC, {925, 290266777}) = 0
  socket(PF_LOCAL, SOCK_STREAM|SOCK_CLOEXEC, 0) = 50
  fcntl64(50, F_GETFL)                    = 0x2 (flags O_RDWR)
  fcntl64(50, F_SETFL, O_RDWR|O_NONBLOCK) = 0

  ..ad infinitum...

  the epoll_wait() is sleeping a very short while before a connect to a
  clickscope named socket path is attempted over and over again. Is this
  rapid polling really necessary?   It's contributing to 0.50%-1.00% of
  the CPU load of the phone.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/unity-scopes-api/+bug/1364464/+subscriptions