For example if i have the piece of code as follows:
CountryName = (char *)malloc((strlen(CountryName)+1)*sizeof(char));
memset(CountryName, 0, strlen(CountryName)+1);
CountryName = SOME VALUE
Now how do i free the memory after use of this code???? :confused: (3 Replies)
Linux Kernels 2.6.16 and up provide a way to instruct the kernel to drop the page cache, inode and dentry caches on command. This tip can help free Linux memory without a reboot.
Note: This is a non-destructive operation. Dirty objects are not freeable, hence; you must run sync beforehand.
... (0 Replies)
Hi,
I am facing one problem, On our Linux server Free memory decreases gradually but my java process memory does not increase.
Please any one tell, why free memory decreases gradually (1MB in approx 15 minutes).
kernel details:-
Linux linux4 2.6.9-42.ELsmp #1 SMP Wed Jul 12 23:27:17 EDT... (13 Replies)
Hi,
How do I determine the free space below?
# vxdg -g msb_db_dg free
DISK DEVICE TAG OFFSET LENGTH FLAGS
msb_db_dg01 sdb sdb 312475648 316571392 n
Please help, I need to increase the file system of mysql folder on red hat ent 4 with vxfs.... (0 Replies)
Hi,
Im working on Solaris 9 on SPARC-32 bit running on an Ultra-80, and I have to find out the following:-
1. Total Physical Memory in the system(total RAM).
2. Available Physical Memory(i.e. RAM Usage)
3. Total (Logical) Memory in the system
4. Available (Logical) Memory.
I know... (4 Replies)
Hi all,
Could please let me know how to get the more memory free space (not added the RAM) in local zone.
-bash-3.00# vmstat 2 5
kthr memory page disk faults cpu
r b w swap free re mf pi po fr de sr s0 s1 s1 s1 in sy cs us sy... (3 Replies)
I was running a program and it stopped and showed "Out of Memory!". at that time, the RAM used by this process is around 4G and the free memory size of the machine is around 30G. Does anybody know what maybe the reason? this program is written with Perl. the OS of the machine is Solaris U8. And I... (1 Reply)
hi- im running glassfish 3.1 on debian server and there are times where I need to start the domain when we cannot access the web application. I checked the memory and it's confusing me. Am i still ok? can you explain the below?
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME... (1 Reply)
Hi guys.
I've a question, if we are using a syscall that receives a string allocated dynamicaly to a determined size, or NUL and it will allocate the apropriate size. We should free the memory or the OS will do it for us?
If a function returns a pointer we should free that poiter when we are done... (7 Replies)
Discussion started by: pharaoh
7 Replies
LEARN ABOUT CENTOS
meminfo
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
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
",
inaddr[i]);
else if ((validity[i] & 2) == 0)
printf("address 0x%llx has no physical page "
"associated with it
", 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
",
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 ALSO memcntl(2), mmap(2), gethomelgroup(3C), getpagesize(3C), madvise(3C), sysconf(3C), attributes(5)SunOS 5.10 21 Feb 2003 meminfo(2)