Questions tagged [memory]
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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Questions on analyzing memory leakage with pmap in Linux
I am working on an embedded Linux system (kernel-5.24.0). And I amm trying to identify a memory leakage of an application, so I chose to use pmap to check the anonymous memory of the application (...
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100% memory consumption when running Jetbrains IDE for 5 min
Fresh install of Arch Linux causes major memory leaks upon opening JAVA based applications, or Jet Brains applications to be exact.
Memory starts off fine but within 5 minutes its up over 90%, opening ...
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My Ubuntu kernel config file does not recognizes all memory available to the system,but only half
The project that I've been working on since 2 years is to enable KVM (with the support of libvirt and virt-manager) on a recent version of Linux and of its kernel on the old but still nice ARM ...
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4GB of memory being used by nothing?
I have 32gb of ram installed in my system, but after running for a day or two, the memory starts to add up out of nowhere. Using free, the system claims that 8.9gb of memory is being used, out of the ...
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Why does my system heavily use swap when there are 86 GB of RAM still usable?
This is not so much a performance problem as it is a desire to understand what is happening and how it works. I have a system with lots of resources, including 128 GB of RAM. What I have discovered (...
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When should I be worried on the output of free -m?
I never figured out how to read this. Some say something, some say something else.
I just want to know when I need to be worried?
total used free shared buff/cache ...
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htop shows lower memory consumption than free -h or top
I have a laptop with Artix Linux installed. When I check my RAM usage using htop, it shows significantly lower memory usage than free -h. Here's an example:
htop:
Mem[||||||||||||| 1.45G/7.60G]...
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What is the correct process to resize logical volumes on Arch Linux
I use an Arch Linux distribution on my lap top and a few days ago I ran an update with the command sudo pacman -Syu. The update was executed succesfully; however, I received the following error,
the ...
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Why `ru_maxrss` returns more usage than expected
I'm testing a program runner. When I'm using GNU time 1.9 to test the code below
// nul.c
#include <stdio.h>
#include <sys/resource.h>
int main()
{
struct rusage r_usage;
getrusage(...
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Limiting process memory usage with systemd-run not working as expected
I'm trying to limit the memory usage of Chrome with systemd-run by starting it with:
systemd-run --scope \
-p MemoryMax=16G \
-p MemoryHigh=15G \
-p CPUWeight=70 \
-p StartupCPUWeight=100 \
/...
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How could we get the USS of a process
As far as I know there are several memory concepts: VSS RSS PSS and USS, in which USS(unique set size) is the physical memory exclusively used by a process(correct me if needed).
I think this should ...
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Memory RAM limited to 50%
I configured 4GB of RAM memory and the OS is only using 2GB.
How to release 100% usage?
Whenever I increase the capacity of the OS, it is only limited to 50% of its capacity.
PS.:
root@ucs-1198:~# ...
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Tool to show memory that would be freed if I terminate a process and its sub processes?
I know that it's a bit tricky to show the memory that a process is using due to the fact that there is memory shared.
But when I look at memory diagnostics, it's normally because my memory is getting ...
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Why does ftruncate with a shared memory object not use memory?
I've observed that I can create a shared memory object and give it ostensibly any size with ftruncate, regardless of the resource limits on my system. The code below sets the size to 262 TB, and ...
- 115
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What does exactly "memory is accountable" mean?
I understand that "accounted memory" means memory that is ensured to be always commited, that means: every page of the VMA is either in RAM or swap, so every page must be allocated.
However, ...
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Getting only used memory from free command every few seconds
It was explained e.g. here:
Get separate used memory info from free -m command
how to cut the output of free command. But I want to do this every few seconds and log it to a file. So I tried:
free -g -...
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DELL R730XD 256GB memory but just showed 251GB on linux with command `free -h` and `htop` , why?
A DELL R730XD server with 32GiB * 8, totaling 256GB of memory, is correctly recognized as 256GB in the BIOS. When checking the memory information using "dmidecode -t memory" in Linux, the ...
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Difference between the `s` permission and the `sh` flag in `VmFlags`
I don't really understand the difference between both "marks" to know if a memory region is "meant to be private" or shared: the permission s and the sh VmFlag.
In which situations ...
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Confusion about memory management terminology (Linux)
I want to know a better way of "naming things" (regarding memory management in linux), to avoid a reader of a writting of mine to misunderstood something, but also avoid long-phrases each ...
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Linux HugeTLB: What is the advantage of the filesystem approach?
Moved Post Notice
I just moved this question (with slight modifications) from a StackOverflow question (which I have deleted, since cross-posting is strongly discouraged), which has not been answered ...
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Who decides the physical address for a particular virtual address, kernel or MMU?
I am trying to understand how the physical addresses are allocated when running an OS.
My question is when the kernel allocates some memory (lets say using kmalloc), who decides what physical memory ...
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How to limit the memory used for each process of a certain binary?
I have a process which is part of standalone, non-service executable.
The process in question spawns thousands of co-processes under a single binary. I'd like to limit the memory usage of processes ...
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Linux uses 6.6Gi RAM for nothing
I'm trying to figure out why my Linux machine is so slow and I found this:
$ free --human
total used free shared buff/cache available
Mem: 7,3Gi 6,...
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heavy timing jitter in a loop that just sums up data, why? only imx8 suffered?
I created in C a small application that does
allocate 2 char buffers of 5 MByte
do a loop 1000 times
in the loop either sum up all elements of array1 or array2 (alternating), so in an internal loop ...
- 115
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1
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How much memory should be left free?
Ever since the lockdowns forced me to use Chromium which used so much memory that it impacted the stability of my system, I always have the gnome system monitor open and obsessively check it for RAM ...
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Periodically print analysis for a long-running C++ program to detect memory leaks?
I have a C++ compiled program (an ELF binary) intended to run forever, similar to an HTTP server. I would like to use Valgrind to analyze the program for any memory leaks. However, Valgrind typically ...
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How to limit Video RAM usage on linux?
some processes on my computer are using way too much video card memory for the tasks they're doing. I'd like to impose a limit on these tasks to have the OS limit the on-card RAM usage of these tasks. ...
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Why isn't access to /proc/pid/mem a security vulnerability?
I've played around a bit with /proc/pid/mem and /proc/pid/maps. I wrote a simple c program that just periodically reads from a variable (whose address is written to stdout), and I was able to change ...
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pmap shows mappings of "other objects" - how do I find out what these are?
I am investigating some sort of a memory leak in my rust application. The memory keeps growing at a steady pace (starts at around 30M and grows 50M per day). The application is written in rust and it ...
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Mismatch on checking memory usage in Linux
I am working on an embedded Linux system (kernel-5.10-24) where there is 64MB RAM in system.
Now I am checking the memory usage in the system, and I found the mismatch of the data.
First, the memory ...
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Will the implementation of mremap free physical pages?
Recently, I am reading the memory management part of linux kernel code (the version I am reading is 4.10). I find that the implementation of mremap is strange.
In short, sys_mremap() will call ...
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Is the system limiting my memory?
I am running some code on a shared remote machine. When running several instances in parallel, they relatively quickly die with std::bad_alloc, while a single instance runs much longer (in any case, 1 ...
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Is there a way to set a hard cap/limit on how much RAM Chrome can use?
I'm using Linux on my Steam Deck (SteamOS/Arch Linux).
Is there a method to set a hard cap/limit on the maximum total RAM Chrome can use with command line arguments? (to 8 GB out of the device's max ...
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How to Add some System Memory to be shared with the GPU in Linux?
I have switched from Windows 10 to linux mint 21.1
I tried playing GTA 5 on lutris (wine emulation) however the game is almost unplayable on linux as big parts of the map will not load because of my ...
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how does linux know how much physical memory is available?
I am trying to understand which Linux kernel function reads the amount of available physical memory.
After that, where this information is stored?
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How to get resource usage from docker build command
I need to track the memory and CPU usage of BUILDING (NOT RUNNING) a docker container.
I have tried using psrecord (along with the include children option) on the PID for the terminal I run docker ...
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TOP vs df -h command memory shows different
I am using solaris 10.
Can someone please help me why both command shows different total memory?
df -h command shows memory total memory SIZE is 900G
~=>df -h /test
Filesystem Size Used ...
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Does QEMU on Linux Ubuntu 20.04.1 x86_64 have a memory leak?
We have a testbed for an OSv project that runs (5.15.0-72-generic - 20.04.1-Ubuntu - x86_64) the same instances a lot of time. The script for the execution of a single run is very simple and follows:
...
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Linux kernel difference between protected and reserved memory? (memmap parameter)
The Linux kernel takes a memmap parameter *) to manually designate memory regions for different use-cases.
Q: What is the difference between reserved memory (memmap=nn[KMG]$ss[KMG]) and protected ...
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Linux "atop" : MEM total - (used + free + cache + hp) doesn't add up
Im trying to find out how "free" memory is calculated. I'm using atop in order to see how much each process consumes, and see how much hp / free / cache memory exists. My problem is that I ...
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Is it safe to set extfrag_threshold to 1000
I am wondering if setting /proc/sys/vm/extfrag_threshold to 1000 is safe? What are the ramifications of changing this setting. By default, it is 500.
Does setting it to 1000 essentially disable ...
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PTRACE_PEEKTEXT ptrace: Input/ouput error
I try to read the values from memory with using PTRACE_PEEKDATA.
To find the memory address of specific line I am using with objdump -
objdump --dwarf=decodedline ./exe_filename
and got the output:
...
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rPi invoking OOMKiller when there is so much memory free
Whenever I'm doing intensive file operations, or just now and then, I have my OOMKiller invoked and something killed. However, I seem to have a lot of free memory when this happens:
[nitz@saturn ~]$ ...
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Ubuntu RAM memory dump
I want to take memory dump of ubuntu machine using pyhton script without using LIME, AVML etc tools. I want to use linux inbuilt command like gcore.
After creating memory dump of all RAM processes I ...
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How is MTD partition layout detected/parsed in Linux?
I am working on an embedded Linux system, which uses kernel-5.10.24.
There is a NAND FLASH used as storage in system, and it has 4 partitons. When the kernel boots up, there shows 4 partitions as ...
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How to check the memory usage in kernel in Linux-5.10.24?
I am working on an embedded Linux system with kernel 5.10.24. And there is 96MB DRAM in system.
When system boots up, I checked the memory usage and got followings.
# dmesg | grep "kernel code&...
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Comuter freezing on full RAM/possible cache problem
After installing Arch Linux on my Notebook I experience a weird problem: Opening firefox or any other browser (or any application with high RAM usage) RAM (12 GB) is filling up pretty quickly, even ...
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Question about Context Switching on x86 in xv6 OS
I'm reading OSTEP for my Operating Systems course, and I have a question from Chp.6.3:
Note that there are two types of register saves/restores that happen
during this protocol. The first is when the ...
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Find out physical memory mapping
I want to debug a memory problem systematically.
My system setup is as follows: I have a (physical) server with 2 CPUs (each with multiple cores). Each CPU has 1 TiB of RAM (16 memory modules with 64 ...
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Oracle Linux 8.x - Performance Test (Stress / Load / IO / Network Usage / Memory Usage)
I want to do performance test on Oracle Linux 8 KVM guest server (It will be used as Application server (WLS 14c) and/or Oracle DB server).
What are the best tools I can provide this with? I saw an ...
