12-23-2011
Quote:
Originally Posted by
Corona688
swap is used as a holding area for RAM. When memory gets low, RAM which hasn't been used recently gets copied into swap space then recycled, given to something else. When something tries to use memory which has been copied into swap, it's forced to wait for it to be read back out of storage.
If the above were true, why does my swap memory increase in size which means something less used from the RAM was transfered to the swap memory even when the process I am starting is -xms=512M and -xmx=512M and the Total current free RAM is 4 GB.
It should ideally allocate 512M from the free 4GB of RAM rather than freeing up space on the RAM inorder to accomodate 512M process.
Can you please explain?
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LEARN ABOUT DEBIAN
sys::statistics::linux::memstats
Sys::Statistics::Linux::MemStats(3pm) User Contributed Perl Documentation Sys::Statistics::Linux::MemStats(3pm)
NAME
Sys::Statistics::Linux::MemStats - Collect linux memory information.
SYNOPSIS
use Sys::Statistics::Linux::MemStats;
my $lxs = Sys::Statistics::Linux::MemStats->new;
my $stat = $lxs->get;
DESCRIPTION
Sys::Statistics::Linux::MemStats gathers memory statistics from the virtual /proc filesystem (procfs).
For more information read the documentation of the front-end module Sys::Statistics::Linux.
MEMORY INFORMATIONS
Generated by /proc/meminfo.
memused - Total size of used memory in kilobytes.
memfree - Total size of free memory in kilobytes.
memusedper - Total size of used memory in percent.
memtotal - Total size of memory in kilobytes.
buffers - Total size of buffers used from memory in kilobytes.
cached - Total size of cached memory in kilobytes.
realfree - Total size of memory is real free (memfree + buffers + cached).
realfreeper - Total size of memory is real free in percent of total memory.
swapused - Total size of swap space is used is kilobytes.
swapfree - Total size of swap space is free in kilobytes.
swapusedper - Total size of swap space is used in percent.
swaptotal - Total size of swap space in kilobytes.
swapcached - Memory that once was swapped out, is swapped back in but still also is in the swapfile.
active - Memory that has been used more recently and usually not reclaimed unless absolutely necessary.
inactive - Memory which has been less recently used and is more eligible to be reclaimed for other purposes.
On earlier kernels (2.4) Inact_dirty + Inact_laundry + Inact_clean.
The following statistics are only available by kernels from 2.6.
slab - Total size of memory in kilobytes that used by kernel for data structure allocations.
dirty - Total size of memory pages in kilobytes that waits to be written back to disk.
mapped - Total size of memory in kilbytes that is mapped by devices or libraries with mmap.
writeback - Total size of memory that was written back to disk.
committed_as - The amount of memory presently allocated on the system.
The following statistic is only available by kernels from 2.6.9.
commitlimit - Total amount of memory currently available to be allocated on the system.
METHODS
new()
Call "new()" to create a new object.
my $lxs = Sys::Statistics::Linux::MemStats->new;
It's possible to set the path to the proc filesystem.
Sys::Statistics::Linux::MemStats->new(
files => {
# This is the default
path => '/proc',
meminfo => 'meminfo',
}
);
get()
Call "get()" to get the statistics. "get()" returns the statistics as a hash reference.
my $stat = $lxs->get;
EXPORTS
No exports.
SEE ALSO
proc(5)
REPORTING BUGS
Please report all bugs to <jschulz.cpan(at)bloonix.de>.
AUTHOR
Jonny Schulz <jschulz.cpan(at)bloonix.de>.
COPYRIGHT
Copyright (c) 2006, 2007 by Jonny Schulz. All rights reserved.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
perl v5.14.2 2012-03-09 Sys::Statistics::Linux::MemStats(3pm)