|
MEMINFO(2) |
System Calls |
MEMINFO(2) |
NAME
meminfo - provide information about memory
SYNOPSIS
#include <sys/types.h>
#include <sys/mman.h>
int meminfo(
const uint64_t inaddr[],
int addr_count,
const uint_t info_req[],
int info_count,
uint64_t outdata[],
uint_t validity[]);
PARAMETERS
inaddr
array of input addresses; the maximum number of addresses that can be processed for each call is MAX_MEMINFO_CNT
addr_count
number of addresses
info_req
array of types of information requested
info_count
number of pieces of information requested for each address in inaddr
outdata
array into which results are placed; array size must be the product of info_count and addr_count
validity
array of size addr_count containing bitwise result codes; 0th bit evaluates validity of corresponding input address, 1st bit validity of response to first member of info_req, and so on
DESCRIPTION
The
meminfo() function provides information about virtual and physical memory particular to the calling process. The user or developer of performance utilities can use this information to analyze system memory allocations and develop a better understanding of the factors affecting application performance.
The caller of
meminfo() can obtain the following types of information about both virtual and physical memory.
MEMINFO_VPHYSICAL
physical address corresponding to virtual address
MEMINFO_VLGRP
locality group of physical page corresponding to virtual address
MEMINFO_VPAGESIZE
size of physical page corresponding to virtual address
MEMINFO_VREPLCNT
number of replicated physical pages corresponding to specified virtual address
MEMINFO_VREPL |
n
nth physical replica of specified virtual address
MEMINFO_VREPL_LGRP |
n
lgrp of nth physical replica of specified virtual address
MEMINFO_PLGRP
locality group of specified physical address
All but
MEMINFO_VLGRP and
MEMINFO_VPAGESIZE require the
PRIV_PROC_MEMINFO privilege.
RETURN VALUES
All but
MEMINFO_VLGRP and
MEMINFO_VPAGESIZE require the
PRIV_PROC_MEMINFO privilege.
RETURN VALUES
Upon successful completion meminfo() returns 0. Otherwise −1 is returned and errno is set to indicate the error.
ERRORS
The
meminfo() function will fail if:
EFAULT
The area pointed to by outdata or validity could not be written, or the data pointed to by info_req or inaddr could not be read.
EINVAL
The value of info_count is greater than 31 or less than 1, or the value of addr_count is less than 1.
EXAMPLES
Example 1 Print physical pages and page sizes corresponding to a set of virtual addresses.
The following example prints the physical pages and page sizes corresponding to a set of virtual addresses.
void
print_info(void **addrvec, int how_many)
{
static const uint_t info[] = {
MEMINFO_VPHYSICAL,
MEMINFO_VPAGESIZE
};
int info_num = sizeof (info) / sizeof (info[0]);
int i;
uint64_t *inaddr = alloca(sizeof (uint64_t) * how_many);
uint64_t *outdata = alloca(sizeof (uint64_t) * how_many * info_num);
uint_t *validity = alloca(sizeof (uint_t) * how_many);
for (i = 0; i < how_many; i++)
inaddr[i] = (uint64_t)addrvec[i];
if (meminfo(inaddr, how_many, info, info_num, outdata,
validity) < 0) {
perror("meminfo");
return;
}
for (i = 0; i < how_many; i++) {
if ((validity[i] & 1) == 0)
printf("address 0x%llx not part of address space\n",
inaddr[i]);
else if ((validity[i] & 2) == 0)
printf("address 0x%llx has no physical page "
"associated with it\n", inaddr[i]);
else {
char buff[80];
if ((validity[i] & 4) == 0)
strcpy(buff, "<Unknown>");
else
sprintf(buff, "%lld",
outdata[i * info_num + 1]);
printf("address 0x%llx is backed by physical "
"page 0x%llx of size %s\n",
inaddr[i], outdata[i * info_num], buff);
}
}
}
ATTRIBUTES
See
attributes(5) for descriptions of the following attributes:
|
ATTRIBUTE TYPE |
ATTRIBUTE VALUE |
|
|
|
Interface Stability |
Stable |
|
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|
MT-Level |
Async-Signal-Safe |
SEE ALSO
memcntl(2), mmap(2), gethomelgroup(3C), getpagesize(3C), madvise(3C), sysconf(3C), attributes(5), privileges(5)