Project

General

Profile

Actions
Copy link

Bug #892

closed

Power: tvheadend is constantly waking the system

Added by Frank Meerköter about 13 years ago. Updated about 9 years ago.

Status:
Fixed
Priority:
Normal
Assignee:
Adam Sutton
Category:
DVB
Target version:
3.2
Start date:
2012-03-06
Due date:
% Done:

100%

Estimated time:
Found in version:
git-fdf89b2
Affected Versions:

Description

I noticed when checking my NAS-box with "powertop" that tvheadend is constantly waking
up the system (wasting energy) even if its not in active use (neither recordings nor live tv).

Cn                Avg residency       P-states (frequencies)
C0 (cpu running)        ( 0.0%)
polling           1.8ms ( 0.1%)
C1 mwait          1.7ms (136.6%)

Wakeups-from-idle per second : 797.2    interval: 5.0s
no ACPI power usage estimate available

Top causes for wakeups:
  38.9% (936.0)   tvheadend
  28.6% (686.8)   USB device  1-7 : MediaTV Digital Home (Sundtek)
  18.9% (455.0)   [ehci_hcd:usb1, uhci_hcd:usb2] <interrupt>
  12.2% (294.6)   mediasrv

An strace on tvheadend shows this activity over and over

[...]
sendto(6, "\0\0\0\0", 4, MSG_NOSIGNAL, NULL, 0) = 4
recvfrom(6, "\1Fo\4\200\4\0\0\0\0\0", 11, MSG_WAITALL, NULL, NULL) = 11
recvfrom(6, "\0\0\0\0", 4, MSG_WAITALL, NULL, NULL) = 4
fcntl(6, F_SETLK, {type=F_UNLCK, whence=SEEK_CUR, start=0, len=0}) = 0
semop(720898, {{0, 0, SEM_UNDO}, {0, 1, SEM_UNDO}}, 2) = 0
semop(720898, {{0, -1, SEM_UNDO}}, 1)   = 0
semop(688129, {{0, 0, SEM_UNDO}, {0, 1, SEM_UNDO}}, 2) = 0
semop(688129, {{0, -1, SEM_UNDO}}, 1)   = 0
fcntl(6, F_SETLKW, {type=F_WRLCK, whence=SEEK_CUR, start=0, len=0}) = 0
sendto(6, "\1Go\2\200\2\0\0\0\0\0", 11, MSG_NOSIGNAL, NULL, 0) = 11
sendto(6, "\334\377", 2, MSG_NOSIGNAL, NULL, 0) = 2
recvfrom(6, "\1Go\2\200\2\0\0\0\0\0", 11, MSG_WAITALL, NULL, NULL) = 11
recvfrom(6, "\334\377", 2, MSG_WAITALL, NULL, NULL) = 2
fcntl(6, F_SETLK, {type=F_UNLCK, whence=SEEK_CUR, start=0, len=0}) = 0
semop(720898, {{0, 0, SEM_UNDO}, {0, 1, SEM_UNDO}}, 2) = 0
semop(720898, {{0, -1, SEM_UNDO}}, 1)   = 0
semop(688129, {{0, 0, SEM_UNDO}, {0, 1, SEM_UNDO}}, 2) = 0
semop(688129, {{0, -1, SEM_UNDO}}, 1)   = 0
fcntl(6, F_SETLKW, {type=F_WRLCK, whence=SEEK_CUR, start=0, len=0}) = 0
sendto(6, "\1Ho\2\200\2\0\0\0\0\0", 11, MSG_NOSIGNAL, NULL, 0) = 11
sendto(6, "\334\377", 2, MSG_NOSIGNAL, NULL, 0) = 2
recvfrom(6, "\1Ho\2\200\2\0\0\0\0\0", 11, MSG_WAITALL, NULL, NULL) = 11
recvfrom(6, "\334\377", 2, MSG_WAITALL, NULL, NULL) = 2
fcntl(6, F_SETLK, {type=F_UNLCK, whence=SEEK_CUR, start=0, len=0}) = 0
futex(0x7bb9e0, FUTEX_WAKE_PRIVATE, 1)  = 1

When attaching gdb i noticed one thread that had constant activity:

Thread 11 (Thread 0x7f3255f5f700 (LWP 32028)):
#0  0x00007f32584a85ad in nanosleep () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x00007f32584d9984 in usleep () from /lib/x86_64-linux-gnu/libc.so.6
#2  0x00007f3259a4720e in __net_read () from /opt/lib/libmediaclient.so
#3  0x00007f3259a3f5c5 in read () from /opt/lib/libmediaclient.so
#4  0x000000000043c57c in read (aux=0x880c50) at /usr/include/bits/unistd.h:
#5  dvb_adapter_input_dvr (aux=0x880c50) at /home/frank/tvheadend/src/dvb/dvb_adapter.c:533
#6  0x00007f3258a1ad8c in start_thread () from /lib/x86_64-linux-gnu/libpthread
#7  0x00007f32584e104d in clone () from /lib/x86_64-linux-gnu/libc.so.6
#8  0x0000000000000000 in ?? ()

The code dvb_adapter_input_dvr() looks like this:

  while(1) {
    r = read(fd, tsb, sizeof(tsb));
    [...]

I understand that EPG-data comes in from DVB but still i wonder if tvheadend
really has to read from the dvb device all the time?

Files

log.jpg (138 KB) log.jpg Piotr Kuchciak, 2016-02-27 11:12
Actions
Copy link

Also available in: Atom PDF