1RPMEM_PERSIST(3) PMDK Programmer's Manual RPMEM_PERSIST(3)
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6 rpmem_persist(), rpmem_read(), -- functions to copy and read remote
7 pools
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10 #include <librpmem.h>
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12 int rpmem_persist(RPMEMpool *rpp, size_t offset,
13 size_t length, unsigned lane);
14 int rpmem_deep_persist(RPMEMpool *rpp, size_t offset,
15 size_t length, unsigned lane);
16 int rpmem_read(RPMEMpool *rpp, void *buff, size_t offset,
17 size_t length, unsigned lane);
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20 The rpmem_persist() function copies data of given length at given off‐
21 set from the associated local memory pool and makes sure the data is
22 persistent on the remote node before the function returns. The remote
23 node is identified by the rpp handle which must be returned from either
24 rpmem_open(3) or rpmem_create(3). The offset is relative to the
25 pool_addr specified in the rpmem_open(3) or rpmem_create(3) call. If
26 the remote pool was created using rpmem_create() with non-NULL cre‐
27 ate_attr argument, offset has to be greater or equal to 4096. In that
28 case the first 4096 bytes of the pool is used for storing the pool
29 matadata and cannot be overwritten. If the pool was created with NULL
30 create_attr argument, the pool metadata is not stored with the pool and
31 offset can be any nonnegative number. The offset and length combined
32 must not exceed the pool_size passed to rpmem_open(3) or rpmem_cre‐
33 ate(3). The rpmem_persist() operation is performed using the given
34 lane number. The lane must be less than the value returned by rp‐
35 mem_open(3) or rpmem_create(3) through the nlanes argument (so it can
36 take a value from 0 to nlanes - 1).
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38 The rpmem_deep_persist() function works in the same way as rpmem_per‐
39 sist(3) function, but additionaly it flushes the data to the lowest
40 possible persistency domain available from software. Please see
41 pmem_deep_persist(3) for details.
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43 The rpmem_read() function reads length bytes of data from a remote pool
44 at offset and copies it to the buffer buff. The operation is performed
45 on the specified lane. The lane must be less than the value returned
46 by rpmem_open(3) or rpmem_create(3) through the nlanes argument (so it
47 can take a value from 0 to nlanes - 1). The rpp must point to a remote
48 pool opened or created previously by rpmem_open(3) or rpmem_create(3).
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51 The rpmem_persist() function returns 0 if the entire memory area was
52 made persistent on the remote node. Otherwise it returns a non-zero
53 value and sets errno appropriately.
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55 The rpmem_read() function returns 0 if the data was read entirely.
56 Otherwise it returns a non-zero value and sets errno appropriately.
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59 rpmem_create(3), rpmem_open(3), rpmem_persist(3), sysconf(3), lim‐
60 its.conf(5), libpmemobj(7) and <http://pmem.io>
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64PMDK - rpmem API version 1.2 2018-03-13 RPMEM_PERSIST(3)