1STALLD(8)                   System Manager's Manual                  STALLD(8)
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NAME

6       stalld - detect starving threads and boost them
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SYNOPSIS

9       stalld  [  -l  ] [ -v ] [ -k ] [ -s ] [ -f ] [ -h ] [ -c cpu-list] [ -p
10       time-in-ns ] [ -r time-in-ns ] [ -d time-in-sec ] [ -t time-in-sec ]
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DESCRIPTION

14       stalld is a system daemon that monitors thread for the starvation  con‐
15       dition.   Starvation  occurs  when a thread sits on a cpu run-queue for
16       longer than the starvation-threshold, meaning the thread has  not  been
17       allowed  to  run for threshold seconds. The thread is boosted using the
18       SCHED_DEADLINE policy and given a time period to run. Once it uses this
19       boost period, the thread is returned to its original scheduling policy.
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OPTIONS

23       -t|--starving_threshold
24              how  long (in seconds) a thread must starve before being boosted
25              [60 s]
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27       -p|--boost_period
28              SCHED_DEADLINE period  in  nanoseconds  for  a  starving  thread
29              [1000000000 ns]
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31       -r|--boost_runtime
32              SCHED_DEADLINE  runtime  in  nanoseconds  for  a starving thread
33              [20000 ns]
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35       -d|--boost_duration
36              duration in seconds the starving thread will run [ 3 s]
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38       -F|--force_fifo
39              force using SCHED_FIFO for boosting
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41       -l|--log_only
42              only log information, do no boosting [false]
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44       -v|--verbose
45              print action informtion to stdout [false]
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47       -k|--log_kmsg
48              log information to the kernel buffer [false]
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50       -s|--log_syslog
51              print information to syslog [true]
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53       -f|--foreground
54              run in the foreground [false (true with -v)]
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56       -P|--pidfile
57              write dameon pid to specified file [none]
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59       -A|--aggressive_mode
60              dispatch one thread per cpu  run-queue,  even  if  thre  are  no
61              starving threads (uses more power).  [false]
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63       -O|--power_mode
64              run  as  a single threaded program, it consumes less CPU, at the
65              price of less precision/granularity.  [false]
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67       -g|--granularity
68              set the granularity (in seconds)  at  which  stalld  checks  for
69              starving  threads.  The lower the value the more precise will be
70              the detection, at the price of consuming more CPU time.  [5 sec‐
71              onds]
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73       -h|--help
74              print options
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FILES

77       /etc/systemd/stalld.conf
78                           parameter file for systemd startup
79       /usr/lib/systemd/system/stalld.service
80                           systemd unit file
81       /usr/bin/stalld     stalld executable

BUGS

83       none

AUTHOR

85       Daniel    Bristot   de   Oliveira   (bristot@redhat.com)   Juri   Lelli
86       (juri.lelli@redhat.com)
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