1
vote
0answers
6 views

Using shared memory through tmpfs and NUMA on x86_64/Linux

Here's what I'd like to do: put a file on tmpfs but ensure that all of it (all pages of it) ends up on the same NUMA node. First, I thought this would be trivial: I'd just mmap() a tmpfs file with ...
7
votes
2answers
66 views

How to make files inside TMPFS more likely to swap

I'm using tmpfs for my /tmp directory. How can I make the computer decide to swap out the files inside the /tmp before swapping out anything that is being used by applications? Basically the files ...
0
votes
1answer
99 views

should I reduce /dev/shm size?

I have a server wity 8 GB RAM Mem: Total 8031464 Used 5146344 Free 2885120 If I execute # df it always returns this tmpfs 4015732 0 4015732 0% /dev/shm What does it ...
4
votes
1answer
185 views

Does tmpfs automatically resize when the amount RAM changes, and does it compete when there's multiple tmpfs?

If I have a tmpfs set to 50%, and later on I add or remove RAM, does tmpfs automatically adjust its partition size? Also what if I have multiple tmpfs each set at 50%. Do multiple tmpfs compete ...
11
votes
3answers
737 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 ...
13
votes
1answer
456 views

Why is /dev full?

The /dev.. is full: SERVER:/dev # df -mP /dev Filesystem 1048576-blocks Used Available Capacity Mounted on udev 12042 12042 0 100% /dev There is no ...
3
votes
1answer
472 views

Does the (source) device in a tmpfs type mount mean anything?

I just went into /etc/fstab (Linux) and changed my line for /tmp (on which a specific ext4 partition was previously mounted) to tmpfs. This was clearly a bit silly, but I wasn't thinking. Anyway, I ...
3
votes
1answer
624 views

tmpfs and vm.swappiness

I have started tuning a bit Linux VM performance on my system (yes. I know that vm.swappiness=0 will kill kittens but I found 30-40 as much better for me as it improved my latency - probably at cost ...
13
votes
3answers
4k views

(How) can I create a tmpfs as a regular (non-root) user?

The distribution is an Ubuntu server running the 2.6.35-30 Linux kernel. I would like to have a directory that sits completely in memory. Is this possible without root privileges?