In computing, memory refers to the state information of a computing system, as it is kept active in some physical structure.

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How do I find the resident memory size of a process on busybox?

I run top on busybox and it shows all processes and their virtual memory size. How do I determine how much RAM is being used by each process?
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2answers
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Discrepancy between reported used memory and sum of application memory usage

I'm running a desktop system that quite regularly suffers from lack of memory, this prompted me to investigate what causes the issue in the first place. Problem is, there's no single process that ...
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7answers
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Correctly determining memory usage in Linux

I'm a bit confused on some of the results I am seeing from "ps" and "free". On my server, this is the result of "free -m" [root@server ~]# free -m total used free shared ...
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1answer
413 views

Java/malloc memory corruption error when running SDK Android Manager

I want to install Android SDK, so I manually installed Java JDK 7u51, downloaded SDK ADT bundle for Linux x64, and tried to run it. When I run android, the SDK manager windows hangs halfway through ...
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3answers
949 views

On system memory… specifically the difference between `tmpfs,` `shm,` and `hugepages…`

I've been curious lately about the various Linux kernel memory based filesystems. Note: As far as I'm concerned, the questions below should be considered more or less optional when compared with a ...
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0answers
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when I use ptrace to attach another process , the process I want to attached Crashed, Why? [migrated]

On Andorid device, i have got root permission. Then I use ptrace to attach another process , some application can be attached, and I can read its' memory successful, but some application will crash ...
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0answers
7 views

EACCESS writing /proc/self/oom_score_adj [migrated]

I'm trying to compile "slock" to implement some tweaks. It fails to start, on this: #ifdef __linux__ #include <fcntl.h> static void dontkillme(void) { int fd; fd = ...
2
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1answer
58 views

What is being cached?

I have an embedded system with a low amount of memory. The system has allocation issues. Maybe due to fragmentation: Memory allocation issue on NOMMU? The platform is a NOMMU platform and so I suspect ...
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2answers
34 views

How to monitor use of Huge Pages per process

I'm trying to determine which process is using a large number of Huge Pages, but I can't find a simple Linux command (like top) to view the Huge Page usage. The best I could find was $ cat ...
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2answers
51 views

Less resource hungry alternative for piping `cat` into gzip for huge files

I have some files of which some are very large (like several GB), which I need to concatenate to one big file and then zip it, so something like this: cat file1 file2 file3 file4 | gzip > ...
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0answers
24 views

About mem and vmem

I am working with a cluster machine running under linux. I have a shell script that uses mpirun to submit my jobs to the cluster machine. In that same script, I can choose the number of nodes that ...
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1answer
50 views

List all files that are present in the cache

This question answers to the question on how to find the what is part of cache. However, in the fincore executable you have to pass the filename to check if it is part of cache. Is there a tools or a ...
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1answer
35 views

Linux server Cpu,memory,swap,run que value to display in percentage

how to write a script to get a linux server below details: CPU |Memory |Swap |Run Queue Peak(%) Relative Avg(%)|Peak(%) Relative Avg(%) ...
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1answer
510 views

Is it possible to find the physical address range of a DIMM?

I note that SMBios Type 20 would help here, but it's optional as of version 2.5 (2006-09-05) pp. 25, L796, and pp. 131, whereas types 16, 17 and 19 are mandatory, but don't quite help. Physical ...
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2answers
2k views

How to reduce ClamAV memory usage?

I'm running a Ubuntu based web server (Apache, MySQL) on a 512MB VPS. This is more than sufficient for the website it is running (small forum). As I wanted to add some protection against viruses I ...
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1answer
54 views

How to check which process is using most memory

When I check free in one of Prod server it showing 70% of memory is being used: total used free shared buffers cached Mem: 164923172 141171860 23751312 ...
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1answer
469 views

Swap space not used

I recently installed Debian 6.0.6. Here are the machine's states: CPU - AMD XP 3000+ RAM - 1 Gig HDD - IDE 80 Gig I primarily use this machine for developing toy personal projects. When I run ...
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1answer
19 views

attaching to Unix shared segment

Can a UNIX program running as root attach to a shared memory segment created by another user with permissions allowing access only to creator?
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1answer
492 views

How to compute Linux slab memory leak in GNU/Linux ( proc/slabinfo ) of running process

How to compute Linux slab memory leak in GNU/Linux ( proc/slabinfo ) of running process ? I'm want to free usage is not working properly . I want to way how to check Memory Usage & Memory Leak ...
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6answers
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How to find which processes are taking all the memory?

I'm looking for somthing like top is to CPU usage. Is there a command line argument for top that does this? Currently, my memory is so full that even 'man top' fails with out of memory :)
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3answers
904 views

Linux / JVM - OutOfMemoryError: unable to create new native thread

I have a memory problem with a Linux server (CentOS). It is a VM. Below is the context. It has 70Gb of RAM. There are 2 tomcat running on it. One tomcat is given a heap of 13Gb and the other one a ...
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2answers
46 views

Find average CPU, vMem, sMem usage on 1, 5, and 15min

I am trying to find at time T the average CPU usage on 1, 5, and 15min, just like what you get from /proc/loadavg Same thing for virtual memory, and swap memory. I would be fine with a python ...
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3answers
84 views

Actual memory usage of a process

The following are the memory usage of mysql and apache respectively on my server. As per the output of pmap say, mysql is using about 379M and apache is using 277M. [root@server ~]# pmap 10436 | ...
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5answers
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What are high memory and low memory on Linux?

I'm interested in the difference between Highmem and Lowmem: Why is there such a differentiation? What do we gain by doing so? What features does each have?
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1answer
395 views

Does sync command remove the dirty cache in the memory?

I am aware that sync command flushes the dirty cache into disk. I have run free command first, then sync, and then free again. The result of latter free command shows more free memory available than ...
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1answer
513 views

Can I use pmap to find out Memory utilization?

I want to measure memory utilization of my Apache Server. Can I use the pmap command and pass all the process IDs of httpd and take that as total utilization? pmap PID1 PID2 .... It seems that pmap ...
0
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1answer
51 views

Opening files of size larger than RAM, no swap used.

I found myself asking this question while doing small experiments and reading upon how memory is managed in Linux. I have a 64-bit Centos 6.5 machine with 512M RAM and 1G SWAP. I created a 1GB file ...
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1answer
321 views

How do you track memory usage in a ksh93 script

We have a number of ksh scripts that run forever (inside a while loop), or at least until a shutdown event is delivered to them. We had a project where these scripts where converted to ksh93 (and ...
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0answers
28 views

AIX Memory Limits

I cannot find these numbers anywhere on the IBM Web site or even random blogs that Google finds. Questions What is the maximum physical memory size a POWER7 CPU supports? What is the maximum ...
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3answers
219 views

How to force Linux kernel to “freeze” (or nearly freeze) for a few hundred milliseconds

We are running a real-time process on a non real-time kernel (CentOS 6), and this is probably not going to change. We have a streaming video application that requires about 500 MB/s of PCIe traffic ...
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2answers
9k views

How to Determine the Amount of RAM Slots In Use?

I forgot how many RAM modules are installed on my laptop. I do not want to unscrew it but want to look it up on the console. How do I gather this information?
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1answer
66 views

Why can't I see my file in RAM?

In nano, I created a simple text file named 'blue_pink_red_orange_green' with the following contents: red blue orange green pink I then opened the file again and did: sudo strings /dev/mem | ...
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0answers
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Zone Normal range in system with 4G RAM

I have a 4GB RAM in my system. Following is my BIOS provided RAM map. [ 0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009d7ff] usable [ 0.000000] BIOS-e820: [mem ...
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183 views

Is Inactive memory related to the Commited but unused?

From the Linux procfs documentation: Active: Memory that has been used more recently and usually not reclaimed unless absolutely necessary. Inactive: Memory which has been ...
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2answers
280 views

Using only 3.3GB but I have 8GB RAM even on Ubuntu 14.04 64bit

I have 2x 4GB(8GB) RAM installed on my motherboard and BIOS/UEFI can confirm it, but on Ubuntu 14.04 64bit only has 3424776kB or 3.266120911GB. uname -a returns: 3.13.0-36-generic #63-Ubuntu SMP Wed ...
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1answer
1k views

How to monitor RAM ECC errors on Ivy Bridge Xeon E3 processor in Linux?

How can I monitor if there are any errors in RAM that get corrected by ECC? The processor is an Intel Xeon (Ivy Bridge) processor, the operating system is Scientific Linux 6.3. On a previous system I ...
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2answers
62 views

How to get a procesess's actual memory usage (including data in swap)

I'm trying to check how much memory strain a process is actually putting on the system, but ps, top and friends are almost useless for that purpose as they only report 3 statistics: RES - the ...
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0answers
17 views

«nm» shows zero VMA: where is the symbol will be mapped?

I am look at the functions of my compiled application via «nm» — I need to find an address to set a breakpoint to the «send()» function. The problem is that this function accordingly to «nm»'s output ...
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2answers
178 views

Reserve fixed RAM memory region as a block device ( with a given start physical address)

There have been a lot of questions about RAM Disks and I am aware of ramfs and tmpfs which allow the use of ram as a block device. However my interest is in using a fixed memory address range as a ...
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1answer
36 views

benefits of huge pages on a laptop/desktop

I have read about huge pages and its the (potential) benefits. However, I am still confused whether this is mostly beneficial on a server with lots of RAM, or if it can be advantageous on a ...
4
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2answers
187 views

Centos 6.5 only using 24GB/48GB of memory

I recently installed an additional 32GB of memory in my Dell PowerEdge R900 home virtual machine server. Memory check passed and I booted into CentOS. When I opened the Virtual machine manager and ...
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3answers
515 views

Viewing virtual memory usage

I started 700+ threads from a single program And my /proc/[PID]/status file shows the following output. VmPeak: 7228104 kB VmSize: 7228104 kB VmLck: 0 kB VmHWM: 3456 kB VmRSS: ...
2
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1answer
102 views

How to get the Physical memory usage in Solaris using commandline

I need to show physical memory statistics in Solaris, like total memory, used and free memory. Don't want to create a script, so is it possible to get all these details using commandline only?
0
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1answer
51 views

Fedora 20 memory.limit_in_bytes not working

Fedora 29 (kernel 3.15.10-201.fc20.x86_64) This worked in F19. I'm trying to use cgroups to limit memory usage for some apps that are prone to misbehaviour, and I'm encountering problems. I'm ...
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0answers
28 views

How fast is a process reading/writting virtual memory?

So, we have top, htop, iotop, iostat, vmstat, etc, to measure many different things on Linux, but how can one measure how much MB/s a process is reading and writting to/from RAM, i.e., virtual memory? ...
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2answers
127 views

How can I force bash to deallocate a brace expanded variable without name?

For benchmarking, I ran the command: for i in {1..100000000}; do echo "$i" line >> file done Bash expanded the braces and stored the list 1 2 3 4 5 6 ... 100000000 in memory. I thought ...
2
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1answer
58 views

Find something that is occupying lots of memory and not visible in `ps` or similar

I have a VM that's having memory issues. One of the tasks I'd like to run in it is crashing with out-of-memory errors. However, when it crashes, the system still stays memory starved. I'm not sure if ...
2
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1answer
104 views

Dirty in /proc/meminfo for dd

I read from here that the below command gives me the amount of data that needs to be written to the disk. grep ^Dirty /proc/meminfo It particularly says Ever ask yourself "How much data would be ...
4
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1answer
213 views

How OOM killer decides which process to kill first?

This answer explains the actions taken by the kernel when an OOM situation is encountered based on the value of sysctl vm.overcommit_memory. When overcommit_memory is set to 0 or 1, overcommit is ...
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1answer
30 views

RHEL 5 Server running with 8 core. Load is always 0 or 1. but RAM (8GB) always occupied

I am seeing load is 0 or 1 since a few weeks on my RHEL5 server with 8 cores. But RAM always fully occupied. I am trying to debug the issue. How can we diagnose where memory is going?