Questions tagged [huge-pages]
The huge-pages tag has no usage guidance.
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Why it takes 7 seconds to reserve ~200GB of huge pages at boot?
I have a server with 300G of RAM and I'm preallocating ~192G of it as huge pages by passing hugepagesz=1G hugepages=192 args to kernel command line.
As a result, I see these lines in dmesg:
[ 1....
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Physical memory addressing and Hugepage allocation on Linux/GRUB with x86 asymmetrical memory channels
Let’s say you have a modern AMD/Intel x86 machine with 2 DRAM DIMMs, configured as asymmetrical dual channel. One of them is 16GB and the other 48GB.
In this case, I want to forbid general usage of ...
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How to allocate huge pages forcibly and synchronously?
On Linux, (non-transparent) huge pages may be allocated by writing into the vm.nr_hugepages sysctl, or, equivalently, into the /sys/kernel/mm/hugepages/hugepages-<SIZE>kB/nr_hugepages sysfs file:...
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Where hugetlb controller is auto enabled?
One kvm virtual machine (8 vcpus+8G memory) of Ubuntu 22.04 with cgroup2 system,
cat /sys/fs/cgroup/cgroup.subtree_control
hugetlb controller included;
But another kvm vm (4 vcpus+4G memory) of ...
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How to change the permission of /dev/hugepages?
I have an app that open() a file under /dev/hugepages to allocate a huge page.
For now, it requires root.
How can I change the permissions?
It's automatically mounted by F38 with:
#/usr/lib/systemd/...
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641
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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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2
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How to enable HugeTLB controller in cgroup v2 on Ubuntu
I am trying to enable HugeTLB Controller on cgroup v2 on my system but can't figure out how.
This is the list of controllers on my system:
cat /sys/fs/cgroup/cgroup.controllers
cpuset cpu io memory ...
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1
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Can a Linux Swap Partition Be Too Big?
Can a Linux swap partition be too big?
I'm pretty certain the answer is, "no" but I haven't found any resources on-point, so thought I'd ask.
In contrast, the main Windows swap file, ...
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Increasing hw.pagesize in FreeBSD
I have a server rocking FreeBSD 13.
From the documentation of sysctl I can read that hw.pagesize cannot be changes on the go. This makes sense to me as this type of parameter depends on the kernel.
I ...
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linux enable large page management
I am doing some experiments. Some huge pages (2MB) are used in the experiment, so that the 21-bit page offset can remain unchanged when performing virtual address translation.
I found some methods on ...
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Linux use huge pages only
I have a x64 Linux system. The page size reported by getconf is 4 k:
$ getconf PAGESIZE
4096
I want the kernel to use only large pages (2 M or 4 M) for all memory allocations. I've calculated that I ...
- 203
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623
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benefits of allocating huge pages at boot
[ moving the question from StackOverflow where it seems less appropriate ]
The kernel boots with default_hugepagesz=1G option, which defines size of the default page size. So when an application want ...
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Enabling Huge Pages on RHEL6 for Oracle 18C xe
I have been trying to switch from oracle AMM to ASMM huge pages. I have done the following changes on RHEL 6
Added following entry in /etc/sysctl.conf ( as suggested by hugepages_setting.sh )
...
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How do I view the number of 1GB hugetables (and what documentation should I follow)?
I am trying to figure out hugepages for use by KVM under Ubuntu 20.04.
If I change the number of 2048 KiB (the default size) pages, I see that is reflected in /proc/meminfo
:~$ echo 0 |sudo tee /sys/...
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Is it possible to disable Transparent Huge pages on the fly?
In order to disable the THP
We did the following on all 635 RHEL machines (we have rhel 7.5 version)
This lines are from bash script that we runs on all machines
Step 1
[[ -f /sys/kernel/mm/...
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Using libhugetlbfs to transparently back up glibc malloc calls in a multi-threaded application
I'm trying to back up the memory allocations of a multi-threaded application with 1GiB hugepages using libhugetlbfs. However, only the main thread allocations are being assigned hugepages. If I ...
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140
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Pmem and huge pages
In my Ubuntu 18.04 Intel system, there are 356gb of DDR. Out of this memory, 300gb, are pre-allocated using the pmem mechanism (since we have an external HW that sends us contiguous data chunks of ...
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1
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why it so important do disable THP ( transparent huge pages ) on database servers? [duplicate]
We have hadoop cluster
We notice that on many DB servers, that the THPs are disabled ( include HDFS servers )
Can you explain why it is so important to disable THP on DB servers?
what could be if ...
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638
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Allocate pools of hugepages separately on each NUMA doamin
On my dual-socket machine, I'm trying to allocated two pools of hugepages (one for each socket), so that the application A, which is pinned on the first socket, uses the first pool, and the ...
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Which distributions enable transparent huge pages "for all applications"?
I am puzzled by LWN again.
Huge pages, slow drives, and long delays -- LWN.net, 2011
It is a rare event, but it is no fun when it strikes. Plug in a slow storage device - a USB stick or a ...
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6
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Understanding main memory fragmentation and hugepages
I have a machine that is intended for general use and which I also used to run a QEMU virtual machine. Because the virtual machine should be as performant as possible, I want to back the VM memory ...
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Linux reproduce error about Transparent Huge Page
I've been doing stress test to check if some process stall error comes out once memory got high load (THP)Transparent Huge Page is enable.
I want to reproduce the error 'Random 'stalls' ocurring ...
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518
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Error configuring large page support on Centos 7 VPS
I am trying to mine Monero with my VPS, but I encountered an error when trying to enable large pages support. The miner I am trying to use is XMR STAK CPU, but I do not believe this to be the issue, ...
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906
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Discover huge page support on POSIX or Linux
I'm working on a program which needs to detect at runtime whether the system it's running on supports hugepages, and if so, what sizes are available. Ideally I'd like this to work for any POSIX ...
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Zend OPcache huge_code_pages: madvise(HUGEPAGE) failed
I've got this error while running a PHP command-line script on a freshly installed server:
PHP Warning: Zend OPcache huge_code_pages: madvise(HUGEPAGE) failed: Invalid argument
The server is ...
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