I am running a series of tests for an implementation of a remote pager that sends page faults to other computers in a network. Long story short, I was wondering if there is an easy way to force a process to use virtual memory as oppose to physical RAM so that I can better measure the performance of my implementation against how the system would perform while swapping to the hard drive.
View 4 RepliesIs there any program which gets the CPU and memory of a process ?
View 1 Replies View RelatedI understand that in linux virtual memory would be the same as swap and I also understand that linux only uses swap when your computer has used all your pc memory. I hope both assumption are right.Can I make a process like firefox use ONLY virtual memory/swap? No access to RAM.
View 6 Replies View RelatedI have a computer with 16GB of ram. At the moment, top shows all the RAM is taken, (NOT by cache), but the RAM used by the various processes is very far from 16GB.I have seen this problem several times, but I don't understand what is happening.My only remedy so far has been to reboot the machine.
View 1 Replies View RelatedI am using malloc and frees a lot in my program. It shows its allocated but when i remove it doesnt show as the memory is removed(I am using the top command to view VIRT memory usage). If this continously grows what would happen to my program (Will it go out of memory?)
View 4 Replies View Relatedwe found that if we use 'top' to show the memory usage of a server (SuSe Linux 10), we can get virtual memory usage as well as 'Resident memory' usage. For virtual mem or a particular process, it is around 1.1GB, which is large but for resident memory, it only consumes 300MB. Are there anyone who knows what the differences are? I would also like to know whether the difference (1.1GB - 300MB) = 800MB are actually available for use by other applications in the system.
View 1 Replies View RelatedI have had a fresh install of Ubuntu 9.10 and installed some software after that.Since third some, some process is eating half of my memory.I have checked processes running in system manager but everything is normal.Maximum is consumed by compiz which is about 26 mb, seems very normal.I did restarted my computer several times, and in the start for 5 mins, its fine after that again my cpu fans runs at very fast speed and my one cpu is used up 95 % (I have dual core).Please help me out, this invisible thing is driving me crazy.I am attaching my htop screen shot (sorted by cpu %), now the cpu is not used by completely but fan is still struggling hard and fast.
View 9 Replies View RelatedI need a command that can get the memory consumption of a process called "job_runner_o".
Running ubuntu 10.10
In linux, how can I display memory usage of each process if i do a 'ps -ef'?I would like to the 'virtual memory', 'res memory', 'shared memory' of each progress. I can get that via 'top', but I want the same info in 'ps -ef ' so that I can pipe the output to 'grep {my process name}'.
View 3 Replies View RelatedIm using SUSE, i have 31GB of memory Mem: 31908592k total, 31429632k used, 478960k free, 12176k buffers. How do I find out what process are eating up all my memory.
View 3 Replies View RelatedDoes anyone know of a linux utility which will prevent all memory in a forked process from being swapped out to disk? I've seen the 'mlockall' call, but hacking the app sounds like overkill.My reason for needing this is that I'm running Windows XP under VirtualBox on my linux netbook, and I'm concerned there are basically two levels of swapping going on, which on a single dinky netbook hard disk isn't
View 3 Replies View RelatedWhat originally seemed like an easy thing to calculate has given me a big headache. Perhaps someone can help me with my issue. I am trying to find, in particular, how much memory certain application processes are taking. The process always is the same name, main_server, but with an argument to tell it what to do when running as a daemon.
When running the following command against all "main_server" processes, it produces a result in megabytes based on the output of the rss field in 'ps'.
Code:
CALC=0
for ea in
`ps -e -orss=,args= |
sort -b -k1,1n |
pr -TW$COLUMNS |
grep main_server |
grep -v "grep main_server" |
[Code]...
Currently I am left scratching my head. For capacity planning purposes, it would be nice to know how many more 'main_server' processes could run on the system without causing it to swap. Knowing the buffer and cache usage will go down as running processes demand more memory, I prefer to look at the free memory excluding cache and buffers. However, since 'ps' is reporting the processes are using more memory than free reports is in use without those things, I have no way to know how many more processes the system can support. I played around with different fields in 'ps', such as vsize, size, etc, but with no luck in matching up any numbers.
Is there any link where i can get information about below?
Dirty memory
RSS
PSS
One more?
if a set of process are getting executed in a use case say 50 times. How do one know the memory leak for a particular process?
I've written a program for a class that my professor will be testing in various low memory environments to see how it behaves when the program runs out of memory. Is there a way I can simulate the execution in a low memory environment without creating a virtual machine?
View 1 Replies View RelatedI want to test that a process properly kills itself and restarts when it can't allocate needed memory. One idea I had was to start other memory-consuming processes and hope that OOM killer kills the process being tested, but 1) this isn't quite the same; 2) it may kill other processes instead; 3) since this is an embedded system, I don't have any programs available except for the system under test and BusyBox.Is there a more direct way to ensure that Linux won't allocate memory to a process?
View 1 Replies View RelatedA process is trying one access to memory, for example through an array (ex.: vect[0]=123. What happens?
Here below what I guess but I'm not sure and accept any comment (please, distinguish between "the system" and "the CPU" in case).
Let's suppose swapping to disk disbled.
We have two scenarios: without and with cache.
If no cache is present in the system:
1. The CPU must discover the phys addr of vect[0] virtual addr. To do that, has to read from 3 (or 2 depending on the system?) pages tables, stored in memory as well.
2. The CPU writes to the final address.
These mean 4 memory accesses.
If cache is present:
1. Like above but, if the pages tables are in cache, we have 3 accesses to that.
2. If the req. page is not in cache, it's reads from ram and transferred to it. Afterwards, cache is written.
In the best case we have 4 cache accesses.
We have designed a board with Cirrus Logic(arm) processor, A Flash memory and some other peripherals have been connected to that. While building kernel we have selected MMU support. We have written few custom drivers for keypad,LED,LCD. But I would like to know how virtual memory mechanism can be helpful here even though there is no any hard disk has been connected. Where will be the virtual memory reside.
View 2 Replies View RelatedI have a 32 bit Ubuntu installed and my Laptop has 4GB RAM, but only 3GB is considered by Linux. My question is: what is the reason for the upper limit on physical memory ?
Code:
dmesg | grep Memory [0.000000] Memory: 3052428k/3112960k available (4673k kernel code, 56364k reserved, 2121k data, 656k init, 2200904k highmem) I am familiar with the virtual memory concept where linux splits upper 1GB for kernel and lower 3GB for user processes. In total, linux 32bit can address 4GB virtual addresses. Does this meant that 1GB of physical memory is already mapped to 1GB of kernel space and Linux only shows the remaining 3GB physical memory left for the user in the above command.
I did some searching on the internet and found some articles related to this, but it only confused me further since some articles suggest 4GB is the upper limit with mentioning whether it's virtual or physical memory, some bring in the concept of PAE, etc. I'm relative new to Linux's memory management, so it'd be really helpful if someone could answer this.
I run a memory-hungry process (mkcromfs) which consumes more memory than I have physical memory on my latop, so it is paging and swappin and thrashing all the time and loadavg is about 2 (compcache is already in use with usual swap partition as well), but slowly moving forward (Although I afraid it will finally try to allocate >2GB and crash draining 2 days of thrashing).
When I want to use the laptop for something else, I stop the process, start X server, firefox and other programs. The problem is that when I start Firefox the loadavg jumps to 10 and the system becomes almost unresponsive at all (long time to turn on/off caps lock, slow mouse cursor position updates, slow switching from X server to Linux console, slow login).
The stopped mkcromfs still holds a lot of memory (464.8 MiB and slowly falling) and moves it to swap only when more memory is needed for some other program, which results in a great slowdown.
How to tell the Linux to swap out this process entirely (e.g. I'm not intending to resume it in short term), possibly waking from swap other data? Also it will be useful to be able to specify the exact swap device to swap the given process out (for example, mkcromfs's memory is useless in ramzswap).
Update: Now I just write a 400-600M of data from /dev/erandom to tmpfs and it makes mkcromfs to shrink. Is there more proper way?
I woukld like to know the kernel command or linux kernel file name where i can get the process actual physical RAM usage in linux version 2.6.21 or hiher version.
View 2 Replies View RelatedI am writing a script that tells me which process consumes the most memory in the system this is what I have but I keep getting an error:
#! /bin/bash
# Autor: Jose miguel Colella
# Descripcion: Que proceso consume mas memoria
ps -e -o %mem -o args | sort -k 1 | tail -n2 | head -n1 | cut -d -f 3
I keep getting this message: cut: delimiter mist be a single character
To get the kernel messages of new java process, i refer the details from /proc/<java pid>/stat and /proc/<java pid>/statm files. For some java processes, I didn't find any details in the /proc/<java pid>/statm file. It has only 7 number of 0s. But /proc/<java pid>/stat file has the details. And also this kind of process will have the life time of nearly 1 minute.
Kernel version using: Linux-2.6.18-8.1.8.el5 Is there any possibility of java process without the memory details in the /proc/<java pid>/statm file? If it is possible, how to know the memory related details of that processes?
I am facing an issue where the process starts hanging. When I closely look at the logs I come to know that some of the child processes that are forked by the parent process are not finished.
1) Is it possible that the child processes that are not finished occupy the socket memory of the parent process and ultimately a point is reached where no socket memory is available to fork new child processes.
2) What is the standard limit of socket memory in linux?
3) What is the fate of such child processes (as I have mentioned above)?
4) How to debug such cases so that the exact problematic area is identified?
clarify me with ulimit output and memory limit?
ulimit -a output:
core file size (blocks, -c) unlimited
data seg size (kbytes, -d) 1572864
[code]...
As i undertsand - out of 1GB of the virtual Address space for Kernel from 3GB to 4GB of the process address space, Kernel image (code, data, bss, stack, heap) resides staring @0x0 address. Vmalloc area starts either at the end of Physical ram size or at 896M. This 896M cap is mandated to ensure that minimum of 128MB is reserved as vmalloc_reserve for vmalloc,kmap etc.
Is the understanding correct? Now trying to map Physical Zones into this 1GB address space
Initial 16MB is mapped to ZONE_DMA
16MB - 896MB is mapped to ZONE_NORMAL
896MB - 1024MB is mapped to ZONE_HIGHMEM
Does this mean that Kernel image is residing in ZONE_DMA area? Any call to vmalloc() in kernel code will return address beyond 896M? insmod of any LKM will internally invoke vmalloc() to obtain contiguous area - where will this code physically located along with rest of kernel code in ZONE_DMA or in ZONE_HIGHMEM?
I'm programming a software system that consists of multiple processes. It is programmed in C++ under Linux. and they communicate among them using Linux shared memory.
Usually, in software development, is in the final stage when the performance optimization is made. Here I came to a big problem. The software has high performance requirements, but in machines with 4 or 8 CPU cores (usually with more than one CPU), it was only able to use 3 cores, thus wasting 25% of the CPU power in the first ones, and more than 60% in the second ones. After many, many research, and having discarded mutex and lock contention, I found out that the time was being wasted on shmdt/shmat calls (detach and attach to shared memory segments). After some more research, I found out that these CPUs, which usually are AMD Opteron and Intel Xeon, use a memory system called NUMA, which basically means that each processor has its fast, "local memory", and accessing memory from other CPUs is expensive.
After doing some tests, the problem seems to be that the software is designed so that, basically, any process can pass shared memory segments to any other process, and to any thread in them. This seems to kill performance, as process are constantly accessing memory from other processes.
Now, the question is, is there any way to force groups of process to execute in the same CPU?. I don't mean to force them to execute always in the same processor, as I don't care in which one they are executed, but that would do the job. Ideally, there would be a way to tell the kernel: If you schedule this process in one processor, you must also schedule this "brother" process (which is the process with which it communicates through shared memory) in that same processor, so that performance is not penalized.
I need to process billions of small files using bash shell commands with limited memory size (256MB). If any of those files contain certain "keywords", the file will be removed. I tried with command:
find . -type f -exec grep -i -l -H "keyword" '{}' + | xargs rm -rf
where all files are located within the current directory. But the command above failed in "out of memory".
This is my sample code in /etc/httpd/conf.d/applications.conf file currently we are creating subdomain mannually for every new subdomain. I want to automate this process througs bash script , how its possible.
Code:
<VirtualHost *:80>
ServerName google.com
ServerAlias google.com
[code]....
In this code which i marked BOLD that content only we'l change for every subdomain. while manually doing this most of the times errors are coming to avoid that i need to automate this process.
I have a query regarding top & virtual memory. When we run top it show VIRT (Virtual Mem), RES (Resident Mem) & SHR (Shared Memory). The total virtual memory of my machine is 4 GBs (2 GB RAM + 2 GB Swap), but still I am able to see a process showing 4000m virtual memory column. what it means, as its show VIRT Mem more than actual available VIRT memory
View 1 Replies View Relatedconcerning controlling the windows in virtual desktop.
a) Say to a application to be launched to virtual desktop 2 for example.
b) How can you ask from a virtual application to be only visible at one virtual desktop. For example I work on virtual desktop 6 and I want to start skype that should be on virtual desktop 2. Right now If I launch the app on virtual desktop 6 it will appear on the same one. Would it be possible to ask for an applicaiton to be launched on an other virtual desktop. If yew how?