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Bug
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Resolution: Done-Errata
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Undefined
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rhel-8.8.0
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iotop-0.6-18.el8
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Yes
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Moderate
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Regression
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None
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ssg_core_services
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18
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22
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2
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QE ack
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False
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False
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No
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Red Hat Enterprise Linux
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None
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Pass
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iotop-0.6-18.el8
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Automated
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None
What were you trying to do that didn't work?
Executing the following command, the fields SWAPIN and IO are always ?unavailable?:
# iotop -b -n 1 Total DISK READ : 0.00 B/s | Total DISK WRITE : 0.00 B/s Actual DISK READ: 0.00 B/s | Actual DISK WRITE: 0.00 B/s TID PRIO USER DISK READ DISK WRITE SWAPIN IO COMMAND b' 1 be/4 root 0.00 B/s 0.00 B/s ?unavailable? systemd --switched-root --system --deserialize 17' b' 2 be/4 root 0.00 B/s 0.00 B/s ?unavailable? [kthreadd]' [...]
The root cause for this is a bad test made to detect whether delayacct is enabled or not (/usr/lib/python3.6/site-packages/iotop/data.py):
457 def sysctl_task_delayacct(): 458 try: 459 with open('/proc/sys/kernel/task_delayacct') as f: 460 return bool(int(f.read().strip())) 461 except FileNotFoundError: 462 return None
Because /proc/sys/kernel/task_delayacct doesn't exist on RHEL8, it always returns None, which is equivalent to False in the end.
On RHEL8, delayacct_on kernel variable is enabled by default (excerpt of kernel/delayacct.c):
26 int delayacct_on __read_mostly = 1; /* Delay accounting turned on/off */ 27 EXPORT_SYMBOL_GPL(delayacct_on); 28 struct kmem_cache *delayacct_cache; 29 30 static int __init delayacct_setup_disable(char *str) 31 { 32 delayacct_on = 0; 33 return 1; 34 } 35 __setup("nodelayacct", delayacct_setup_disable);
Hence the proper condition should be the following Python snippet instead:
21 from procfs import cmdline [...] 458 def sysctl_task_delayacct(): 459 return 'nodelayacct' not in cmdline().keys()
Please provide the package NVR for which bug is seen:
iotop-0.6-17.el8.noarch (REGRESSION compared to iotop-0.6-16.el8.noarch)
How reproducible:
Always, just execute "iotop -b -n 1" on RHEL8
- links to
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RHBA-2024:126364
iotop update
- mentioned on
