bcc-slabratetop(8)

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

6       slabratetop  - Kernel SLAB/SLUB memory cache allocation rate top.  Uses
7       Linux BPF/bcc.
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SYNOPSIS

10       slabratetop [-h] [-C] [-r MAXROWS] [interval] [count]
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DESCRIPTION

13       This is top for the the rate of kernel  SLAB/SLUB  memory  allocations.
14       It works by tracing kmem_cache_alloc() calls, a commonly used interface
15       for kernel memory allocation (SLAB or SLUB). It summarizes the rate and
16       total  bytes  allocated of these calls per interval: the activity. Com‐
17       pare this to slabtop(1), which shows the current static volume  of  the
18       caches.
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20       This  tool  uses kernel dynamic tracing of the kmem_cache_alloc() func‐
21       tion.
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23       Since this uses BPF, only the root user can use this tool.
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REQUIREMENTS

26       CONFIG_BPF and bcc.
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OPTIONS

29       -C     Don't clear the screen.
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31       -r MAXROWS
32              Maximum number of rows to print. Default is 20.
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34       interval
35              Interval between updates, seconds.
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37       count  Number of interval summaries.
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EXAMPLES

40       Summarize active kernel SLAB/SLUB calls  (kmem_cache_alloc()),  showing
41       the top 20 caches every second:
42              # slabratetop
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44       Don't clear the screen, and top 8 rows only:
45              # slabratetop -Cr 8
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47       5 second summaries, 10 times only:
48              # slabratetop 5 10
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FIELDS

51       loadavg:
52              The contents of /proc/loadavg
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54       CACHE  Kernel cache name.
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56       ALLOCS Allocations (number of calls).
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58       BYTES  Total bytes allocated.
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OVERHEAD

61       If  kmem_cache_alloc()  is called at a high rate (eg, >100k/second) the
62       overhead of this tool might begin to be measurable.  The  rate  can  be
63       seen in the ALLOCS column of the output.
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SOURCE

66       This is from bcc.
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68              https://github.com/iovisor/bcc
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70       Also  look  in  the bcc distribution for a companion _examples.txt file
71       containing example usage, output, and commentary for this tool.
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OS

74       Linux
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STABILITY

77       Unstable - in development.
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AUTHOR

80       Brendan Gregg
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