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

learn more… | top users | synonyms

0
votes
0answers
25 views

Best small distro for ROM burning of the system for an embedded system

I am building a specific device and I would like to know what Linux based small distribution would be good when I would choose the put-Linux-on-the-ROM route, so, that the system is not possible to ...
1
vote
0answers
20 views

How to check if an application uses my video card memory?

We can check the core, cpu utiliztion, memory etc of a particular process. Can we check if it uses video card too and if it is how much memory it is using?
3
votes
2answers
2k views

What's the difference between ioremap and file operation mmap?

I'm currently working on a PCI device driver for Ubuntu. I have some example code about PCI driver, but I have difficult on understanding the ioremap and file_operation.mmap. The description of file ...
0
votes
0answers
47 views

how to enable 1MB dma-kmalloc

I'm running a ubuntu 15.10 VM and testing code that will allocate 1MB dma buffers. However, from the /proc/slabinfo, the max that can be allocated is 8K dma-kmalloc-8192 0 0 8192 4 ...
0
votes
1answer
27 views

What is taking up my memory in my Linux virtual machine

I'm trying to debug an application (mongodb) memory usage on a a virtual machine. mongod, is taking 11% of memory. I know this by using top but when I want to see how much of my 7.5GB is free, I ...
1
vote
0answers
23 views

Working my way through dmesg output on a custom 3.5.4 kernel

Having read this thread here: What does the Virtual kernel Memory Layout in dmesg imply? It sounds like 'lowmem' is exclusively meant for kernel-space. [ 0.000000] virtual kernel memory layout: ...
2
votes
2answers
31 views

What tools can I use to diagnose the exact reason for laptop slowness? And how do I use those tools?

I am running Linux Mint 17 on my laptop. When using applications (mainly Web Browsers) the machine freezes for little time periods. The CPU indicates 100% usage at such times, but this only seems to ...
3
votes
0answers
295 views

Boot rescue kernel at high memory address using kexec on arm

Summary: Crashkernel boots at 512MB address in RAM with kexec -e/-l but not with kexec -p - why? Embedded platform with Marvell Armada XP (MV78460) (ARMv7 with 4 cores) and 1GB of RAM. production ...
2
votes
0answers
320 views

Is unreclaimable memory allocated to slab considered used or available cache?

After evaluating /proc/meminfo, I see the following information: $cat /proc/meminfo MemTotal: 197852592 kB MemFree: 64755992 kB MemAvailable: 65655112 kB Buffers: 4388 kB ...
0
votes
0answers
79 views

Where is my memory being used?

Only 28G is being used by buff/cache. $free -h total used free shared buff/cache available Mem: 188G 87G 72G 17M 28G ...
3
votes
1answer
169 views

How do you prevent system from freezing when memory is used up?

I've been running a process (gdb) that can easily use up all my ram and swap space. Every time that happens the whole system becomes very non-responsive and Xorg will barely update, I can't swith to ...
0
votes
1answer
51 views

How do I check how much total memory my VM has? [closed]

I've tried /proc/meminfo but my permission has been denied.
3
votes
1answer
202 views

What is the usual Allocation unit for a process on Linux?

I'm currently studying memory management in Operating Systems. Allocation Unit is the smallest unit of memory the OS will give to any process. I've read in this page, in the 'Memory allocation ...
0
votes
1answer
3k views

find: cannot fork: Cannot allocate memory

I want to delete 1 file at a time from my directory which contains so many files,So i want to remove 1 file at a time. Just to avoid too many reads and failed at too many arguments. find ./Backup/...
2
votes
0answers
56 views

What does it mean when a private VM page is none of `rwx`?

UPDATE: It's a padding: every such non-rwx area is preceded with a readable and/or writable area and together they constitute a 64Mb segment (for 64bit architecture). A relevant question on SO: http:...
3
votes
1answer
87 views

Shared memory v/s physical memory

I have a C++ process which is using shared memory to store and transfer data between its child processes. I want to check the shared memory usage while the parent process is executing just like top ...
2
votes
1answer
293 views

How can two identical virtual addresses point to different physical addresses?

Following a fork() call in Linux, two processes (one being a child of the other) will share allocated heap memory. These allocated pages are marked COW (copy-on-write) and will remain shared until ...
0
votes
1answer
74 views

Finding memory corruption bugs in Linux and FreeBSD

In windows, we can enable page heap verification using gflags to catch memory corruption bugs more easily. Is there a similar service/program for Linux and FreeBSD operating systems?
0
votes
1answer
65 views

difference between inactive and free memory in output of FreeBSD top utility?

top -d1 displays following SDRAM usage statistics on one of my older machines: 125M Active, 42M Inact, 51M Wired, 17M Cache, 34M Buf, 2720K Free In total, there is 256MiB of memory installed. ...
0
votes
1answer
154 views

SOLVED Linux mint 17.1 keeps crashing

MODERATOR PLEASE CLOSE I have recently installed Linux Mint 17.1 Cinnamon on an Compaq presario c700 w/intel pentium dual core. It is dual booting with windows vista. The partition size is 19gb. I ...
3
votes
0answers
127 views

Process killed by OOM killer when plenty of memory apparently free

I'm working on an embedded ARM-based platform. 32-bit, 512MB of RAM, no swap. Linux 3.10.53 (some variety of Ubuntu, if that's relevant). Some code I'm working on is getting consistently oom-killed, ...
0
votes
1answer
51 views

Hardware specs for Linux machine for cluster administration [closed]

I have just started as cluster system administrator and was asked to choose some features to get bought a personal machine to work on, and most intensive calculations will be perform in the cluster. I ...
1
vote
0answers
35 views

Debian - Memory usage [closed]

I all, I'd like to understand what happens in this system. Running top I get: KiB Mem: 496948 total, 460012 used, 36936 free, 68604 buffers and in the process list the process that ...
1
vote
1answer
1k views

What happens after a page fault?

When a page fault occurs in a Linux system, the interrupt-handler has to figure out the reason why the page fault happened. But how ? Is there anywhere a special number for that !? If yes, where is ...
1
vote
1answer
114 views

How to read .vma files?

I am trying to read a .vma file but no luck finding an application to do it on Linux.. I tried to google it but it didn't work out.. The file was produced by Volatility on Ubuntu Linux 12.04 using ...
3
votes
0answers
95 views

Memory consumption over variable period of time

There are a number of questions on this StackExchange about memory consumption, notably: How to check which process is using most memory How to display top results sorted by memory usage in real ...
2
votes
0answers
263 views

Portable way to parse /proc/meminfo

I'm having trouble finding a generic code that work, here, for both CentOS 5/6 and CentOS 7 versions pc the /proc/meminfo file. I Want to compute the "Real Used memory" like free does. (amounts ...
0
votes
0answers
169 views

Dump XEN guest memory image

I am new into memory forensics thing and I am trying to dump a memory image from a XEN guest (Ubuntu 12.04 x64 - domU) in order to analyze it on dom0 (Ubuntu server 12.04 x64) with volatility . For ...
1
vote
0answers
2k views

Bash session errors on commands: “fork: Cannot allocate memory”

I have a bash session open to a remote server and something is wrong. I created a directory "test" and touched the files inside touch 1 2 3 4 5. I then tried to copy the directory cp test/ test2/ and ...
2
votes
1answer
52 views

Is there a brief way to view the top resource usage(CPU, memory or even bandwidth) of a program after its running?

I know I can use top to view the overall real-time CPU & Memory usage, and nload for overall real-time bandwidth usage. But I wish to view the maximum(or average) CPU, Memory, & bandwidth ...
1
vote
1answer
53 views

Cached Memory but swap is being used [duplicate]

I've got a VM with 16gb of memory and recently it's been using some of the swap space. At first I thought this was because it was using all the memory but then I read some articles about the Cached ...
4
votes
1answer
296 views

Shared library mappings in /proc/pid/maps

Why does /proc/pid/maps contain a few records for the same library ? Here is an example: 7fae7db9f000-7fae7dc8f000 r-xp 00000000 08:05 536861 /usr/lib/x86_64-linux-gnu/libstdc++....
1
vote
1answer
25 views

upstart jobs - privileged vs unprivileged

On one of my VMs, some upstart jobs were failing, and when I checked df, showed that I had run out of disk-space (Use% was 100 on /dev/sda1). What I did not get is: the jobs which were running with ...
2
votes
1answer
72 views

Why is IO so high when almost out of memory

On my work laptop with an SSD and no swap, I sometimes run out of memory when running RAM-expensive applications (virtual machine, etc). When that happens, the system becomes slow (expected) but what ...
1
vote
1answer
244 views

Memory usage of a given process (using Linux proc filesystem)

I want to know which files from /proc directory and which fields of these files I need to calculate the memory usage of a given pid. I've been using the "stat" file and the "vsize" parameter that is ...
5
votes
4answers
238 views

How do see the memory used by a program in ubuntu?

How can I see the raw memory data used by an application ? Like , suppose I have a file name something.sh . Now I run the command ./something.sh , and then I want see all the data its accessing in ram ...
0
votes
0answers
19 views

How to troubleshoot High VIRT and RES memory on a Standby Server

We currently run TIBCO EMS on our RHEL6 servers, it is Active-Passive setup, for some reason we are seeing a really high VIRT and RES usage by the standby instance (approx 198GB). The application (...
1
vote
1answer
31 views

tstime and memory usage

So I am interested in measuring the high-water memory usage of a process. I would love to be able to use tstime but am having troubles figuring it out. Does it work in Unix? When I go to https://...
3
votes
1answer
235 views

How to run free command by crontab

I want to run this command: free && sync && echo 3 > /proc/sys/vm/drop_caches && free -m by cron. That way I can free my RAM and cache in an Ubuntu system. I'm using ...
3
votes
2answers
417 views

Memory usage of an infinitely looping shell script

So, I have a shell script for updating a MySQL database that looks something like this: #!/bin/sh mysql -h "localhost" -u "root" "-p********" "database" < "update.sql" sleep 5 sh $0 It sleeps ...
3
votes
2answers
355 views

Physical Address Extension - how do virtual addresses work?

I'm running Debian Linux. uname -m says i686 which means 32-bit architecture machine with pae flag enabled. getconf LONG_BIT is 32. Installed RAM capacity is 6GB. My /proc/cpuinfo has an entry ...
0
votes
1answer
109 views

Storage allocator out of space error on unix shell script

While running the script called abc.sh, following errors are thrown. abc.sh: line 226: storage allocator out of space on 64946176 byte request ( region 64329285632 segments 1981 busy 202:65087584:...
1
vote
0answers
65 views

Why process is killed while a lot of memory is free?

I am running a python script in ipython. This script will take about 8GB RAM. The system has more than 80 GB free RAM but the swap is nearly 0. My script was killed after it runned for a while. I want ...
2
votes
1answer
44 views

Can I trust in memory information of dmicode?

I want to buy 16gb memory for my notebook. I ran dmicode and found this information: Handle 0x0005, DMI type 5, 20 bytes Memory Controller Information Error Detecting Method: None ...
0
votes
0answers
43 views

/proc filesystem - getting useful information

I'm trying to understand the values in /proc/PID/status. I want to calculate cpu% & mem% used by PID, similar to top bash command. For Memory percentage usage I can do the following (correct me ...
3
votes
1answer
157 views

Resource (CPU time and memory) limitation and termination of a process upon violation in Linux

The problem: Given a process, limit the resources it and its child-processes can use. I.e. set CPU time and virtual memory quotas. When the process group exceeds one of the limits, terminate it, ...
2
votes
1answer
140 views

What does Linux spend memory on other than userland, caches and slab?

I have a system with 1 GB of physical RAM. Right now, free shows the following memory usage: total used free shared buffers cached Mem: 1026360 863660 ...
2
votes
0answers
49 views

Which process wrote to which memory address? [closed]

Recently, I've been seeing a wide variety of memory-related crashes at work (C++ applications on Ubuntu 14.04). Our applications use a properietary third party library to interface with real time data ...
2
votes
1answer
179 views

How to find the page size of physical memories from userspace?

I want to understand the page size, sector size, block size (if applicable) of a usb flash drive. Is there a way for me to inspect those with Ubuntu? mount /dev/sda1 /mnt ? umount /dev/sda1 Edit ...
0
votes
0answers
100 views

Is High Virtual Memory usage a problem or may cause problems?

In our server, we have a python based code that listen ports. The amount of Virtual Memory it uses is increased greatly with time Like: USER PID %CPU %MEM VSZ RSS TTY STAT ...