htop doesn't report shared memory usage on Linux

[jart]

In the screenshot below, you'll see that one of my processes is using 139GB of memory, but htop reports the system using 6GB of RAM.

It's because htop hides mmap(MAP_SHARED) memory. This has caused a great deal of confusion in the machine learning community over the past year. For example https://twitter.com/JustineTunney/status/1778420352504512774 one Twitter user got snagged by poor performance because his system was swapping, but according to htop everything was fine.

Could htop start reporting this information? Thanks!

[BenBE]

Okay, something seems off here …

Can you provide a copy of /proc/meminfo with what htop reports alongside? Shared memory should be handled already.

Also, which htop version/release?

[fish98]

Hi, I might experience the same issue with htop version 3.3.0-2 on ArchLinux where the swap memory usage statistics of htop differs from those shown by top and /proc/meminfo. Please find the following screenshot for more detailed information. I tested Line 213-215 in linux/LinuxMachine.c and found these variables match with the correct memory consumption listed in meminfo. I suppose these variables were incorrectly changed during the whole htop workflow although I have not investigated the root cause in depth.

PTAL, thank you :)

[cgzones]

@fish98 your observed behavior is probably due to the zswap handling, see https://github.com/htop-dev/htop/commit/71f5a80d9e312375eff28d2fbb7d8add81f6793c and https://github.com/htop-dev/htop/commit/71f2e66126286540ca88d8c36f81008ba5181f89

[fish98]

@fish98 your observed behavior is probably due to the zswap handling, see 71f5a80 and 71f2e66

Thanks for your reply :)