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comp.unix.aix Frequently Asked Questions (Part 2 of 5)
Section - 1.301: How much should I trust the ps memory reports?

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Top Document: comp.unix.aix Frequently Asked Questions (Part 2 of 5)
Previous Document: 1.300: Some info about the memory management system
Next Document: 1.302: Which simms do RS6000's use?
See reader questions & answers on this topic! - Help others by sharing your knowledge

Using "ps vg" gives a per process tally of memory usage for each running
process.  Several fields give memory usage in different units, but these
numbers do not tell the whole story on where all the memory goes.

First of all, the man page for ps does not give an accurate description
of the memory related fields.  Here is a better description:

RSS - This tells how much RAM resident memory is currently being used
for the text and data segments for a particular process in units of
kilobytes.  (this value will always be a multiple of 4 since memory is
allocated in 4 KB pages).

%MEM - This is the fraction of RSS divided by the total size of RAM for
a particular process.  Since RSS is some subset of the total resident
memory usage for a process, the %MEM value will also be lower than actual.

TRS - This tells how much RAM resident memory is currently being used
for the text segment for a particular process in units of kilobytes. 
This will always be less than or equal to RSS.

SIZE - This tells how much paging space is allocated for this process
for the text and data segments in units of kilobytes.  If the executable
file is on a local filesystem, the page space usage for text is zero. 
If the executable is on an NFS filesystem, the page space usage will be
nonzero.  This number may be greater than RSS, or it may not, depending
on how much of the process is paged in.  The reason RSS can be larger is
that RSS counts text whereas SIZE does not.

TSIZ - This field is absolutely bogus because it is not a multiple of 4
and does not correlate to any of the other fields.

These fields only report on a process text and data segments.  Segment
size which cannot be interrogated at this time are:

       Text portion of shared libraries (segment 13)

       Files that are in use. Open files are cached in memory as
       individual segments.  The traditional kernel cache buffer
       scheme is not used in AIX 3.

       Shared data segments created with shmat.

       Kernel segments such as kernel segment 0, kernel extension
       segments, and virtual memory management segments.

Speaking of kernel segments, the %MEM and RSS report for process zero
are totally bogus for AIX 3.1.  The reason why RSS is so big is that the
kernel segment zero is counted twice.  For AIX 3.2, this has been
changed, but the whole story is still not known.  The RSS value for
process 0 will report a very small number of the swapper private data
segment.  It does not report the size of the kernel segment 0, where the
swapper code lives.

In summary, ps is not a very good tool to measure system memory usage. 
It can give you some idea where some of the memory goes, but it leaves
too many questions unanswered about the total usage.

User Contributions:

But remnants' crop burning hits harvesting hard

This sunday, quite possibly 28, 2019 snapshot, Provided by the city service group, jointly for Jarniyah, contains been authenticated based on its contents and other AP reporting, Shows Syrians lifetime extinguish a fire in a field of crops, wearing Jaabar, Raqqa state, Syria. Thousands of acres of wheat and barley fields in both Syria and Iraq have been scorched by the fires within harvest season, that typically runs until mid June. "The life that we live here is already bitter, " stated Hussain Attiya, A farmer from Topzawa Kakayi in upper Iraq. "If the outcome continues like this, I would say that no one will continue to be here. I plant 500 to 600 acres on a yearly basis. still, I won't be able to do that because I can't stay here and guard the land day and night. "ISIS militants have a history of working with a "Scorched earth insurance coverage " In areas from that they can retreat or where they are defeated. Ahmed al Hashloum thoughts Inmaa, Arabic for benefits, A local civil group that supports farming. all it takes is a cigarette butt to set haystacks on fire, He brought up. Said the fires are threatening to disrupt normal food production cycles and potentially reduce food to protect months to come. The crop burning remains localized and can't be compared to pre war devastation, Beals considered that. "suffice to say, It is only the beginning of the summer and if the fires continue it could lead to a crisis, " Beals recounted,AlternativeHeadline,prepared crop burning blamed on ISIS remnants compounds misery in war torn Iraq and Syria"}

But good news is short lived in this part of the world, Where residents of the two countries struggle to face seemingly never ending violence and turmoil amid Syria's civil war and attacks by remnants of the Islamic State of Iraq and Syria (ISIS) social groups. of course, Even in locations where conflict has subsided, Fires currently raging in farmers' fields, depriving them of valuable crops.

The blazes have been blamed also consider on defeated ISIS militants seeking to avenge their losses, Or on Syrian regime forces battling to rout other armed groups. Thousands of acres of wheat and barley fields in both Syria and Iraq have been scorched by the fires within harvest season, what kind runs until mid June.

ISIS militants have a history of implementing a "Scorched earth guideline" In areas from which retreat or where they are defeated. this "A means of inflicting a collective punishment on those put aside, said Emma Beals, a completely independent Syria researcher.

ISIS militants claimed obligations for burning crops in their weekly newsletter, al Nabaa, Saying they targeted farms owned by senior officials in six Iraqi provinces and in Kurdish administered eastern Syria, sending the persistent threat from the group even after its territorial defeat.

ISIS said it burned the farms of "The apostates in Iraq together with the Levant" And required more.

"It seems that it'll be a hot summer that will burn the pockets of the apostates as well as their hearts as they burned the Muslims and their homes in the past years, this great article said.

countless acres of wheat fields around Kirkuk in northern Iraq were set on fire. Several wheat fields in the Daquq district in southern Kirkuk burned for three days straight yesterday.

In eastern Syria's Raqqa state, Farmers battled raging fires with items of cloth, bags and water trucks. Piles of hay burned and black smoke billowed above the job areas.

The Syrian Observatory for Human Rights said through 74,000 acres (30,000 hectares) linked farmland in Hassakeh, Raqqa and completely to Aleppo province to the west, Were scorched.

Activist Omar Abou Layla said local Kurdish led forces failed to react to the fires in the province of Deir el Zour, Where ISIS was uprooted from its last property in March, (...)

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Top Document: comp.unix.aix Frequently Asked Questions (Part 2 of 5)
Previous Document: 1.300: Some info about the memory management system
Next Document: 1.302: Which simms do RS6000's use?

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