1MEMTIER(1)                          MEMTIER                         MEMTIER(1)
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NAME

6       memtier - redirect malloc calls to memkind memory tiering
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SYNOPSIS

10       memtier [ -r ratio ] [ -t thresholds ] program args...
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DESCRIPTION

14       memtier  runs the given program, redirecting memory allocations to dif‐
15       ferent memory tiers based on a given policy.   This  allows  unmodified
16       programs  to run following a non-greedy allocation scheme that avoids a
17       performance cliff when DRAM is exhausted.
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OPTIONS

21       -r ratio
22              Specifies the ratio as a pair of integers separated by a  colon,
23              where  the first number gives the relative share of near DRAM to
24              be used while the second number gives "far" memory,  be  it  CXL
25              memory  or  PMEM.  Eg.  "1:4" means that 20% of allocations will
26              use DRAM, 80% PMEM.
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28              If the ratio is not given, it defaults to the relative share  of
29              physically installed memory.
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31              This  version  of  memtier  recognizes  only two tiers (DRAM and
32              KMEM_DAX).
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35       -t thresholds
36              Turns on DYNAMIC_THRESHOLD  mode  where  small  allocations  are
37              served  from DRAM and large ones from far memory.  The syntax is
38              described   in   depth    in    man    libmemtier,    eg.     -t
39              INIT_VAL=1024,MIN_VAL=512,MAX_VAL=65536  starts with a threshold
40              of 1024, then varies it between 512..65536 attempting  to  match
41              the requested ratio.
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44       -v     Displays settings that are passed to libmemtier.
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47       -h     Shows a help message then exits.
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CAVEATS

51       This  tool  doesn't  expose  all features of libmemtier.  Only DRAM and
52       KMEM_DAX memory is supported, to use FS_DAX you need to  configure  the
53       library directly, please refer to its man page.
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55       Or  alternatively,  you  can  switch that memory to KMEM_DAX mode.  For
56       that purpose, please refer  to  "man  ndctl-reconfigure-namespace"  and
57       "man daxctl-reconfigure-device".
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SEE ALSO

61       libmemtier(7), memkind(3), malloc(3)
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65Intel Corporation                 2022-02-21                        MEMTIER(1)
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