meminfo(2) System Calls meminfo(2)NAMEmeminfo - 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 correspond‐
ing 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 vir‐
tual address
MEMINFO_PLGRP locality group of specified physical address
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 corre‐
sponding 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 │
├─────────────────────────────┼─────────────────────────────┤
│MT-Level │Async-Signal-Safe │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOmemcntl(2), mmap(2), gethomelgroup(3C), getpagesize(3C), madvise(3C),
sysconf(3C), attributes(5)SunOS 5.10 21 Feb 2003 meminfo(2)
