2 Settings I change on every htop which makes a HUGE difference.
1. I disable user threads. Those mostly just clutter up the htop view while providing no useful information.
2. I enable the process tree view. Very frequently, where a process comes from is much more important than other information. It also lets you see and track things like a compiler process which is eating through a bunch of files.
IMO, both these things should be the default behavior of htop.
I appreciate the note on virtual memory not being reliable. This is what Windows task manager reports by default and it's terrible. Resident size is the most reliable metric. Anything else can be wrongfully inflated by things like harmless memory mapped files that won't actually hurt anything. eg. memory map 2GB of logfiles, it'll only be paged in if reading that portion of the logfile so isn't really using memory but users look at the processes and claim "OMG why does this app use so much memory". It doesn't. It uses very little. You're reading the memory usage wrong. Chrome actually had this problem for a while and they moved away from using memory mapped files. Not because memory mapped files are a bad thing but because users will read the memory usage and go crazy over what they see even though it's not really using that much actual physical memory.
There's actually guides out there on the web that tell people judge usage by virtual memory allocated too :(. At least this article gets it right :).
If you use memory-mapped files, cached pages count towards the resident set size of your process. If you use ordinary file I/O, they don't. That behavior has amusing consequences in HPC clusters that monitor the memory usage of each job and kill them if they use more memory than they requested.
When I read stuff like this, I come to the realization that even after daily driving Linux for 20+ years I still barely utilize its full potential. Great article.
For top if you use the > character it will sort by memory usage. I use that sometimes to figure out why my host is becoming laggy. Also you'll see swapd is taking up CPU.
For the ones that don't know "nmon", have a look at it as well! (press "h" to see the list of available monitors - press it again to make it go away, press "q" to quit)
Nowadays most of my processing happens on the GPU, so htop/top better evolve or become mostly irrelevant because a tool that will support both CPU __and__ GPU will replace it.
> Nowadays most of my processing happens on the GPU, so htop/top better evolve or become mostly irrelevant
If you’re a 3D rendering designer, an ML engineer or a crypto bro, then sure.
Here are the common workloads (for the average SWE on HN) that use CPU/RAM:
- compilation/builds
- language servers and IDEs
- test suites
- local containers
- local databases
- node tooling
- browsers
- data processing
- compression and encryption
- searching/indexing
As others mention it - it seems to shows the Watts used as well :) (and network, and GPU, and disks,....)
[0]: https://github.com/aristocratos/btop
1. I disable user threads. Those mostly just clutter up the htop view while providing no useful information.
2. I enable the process tree view. Very frequently, where a process comes from is much more important than other information. It also lets you see and track things like a compiler process which is eating through a bunch of files.
IMO, both these things should be the default behavior of htop.
There's actually guides out there on the web that tell people judge usage by virtual memory allocated too :(. At least this article gets it right :).
https://nmon.sourceforge.io/pmwiki.php
Especially disk throughput and I/O (keys "d" & "D") can be very useful.
I use htop often but pretty much only use it to find pid or cpu-culprits, and never really understood the rest.
You'll be glad you did.
https://github.com/fenrus75/powertop
What good does it do to stick your head in the sand?
CPUs are great for orchestrating work, GPUs are great for actually doing the work.
Right, and wouldn't it be really nice if we could check on our orchestrators to make sure their not bottlenecking ops?
"How come we can fully load the GPUs?" "Idk boss, amelius said htop et al were irrelevant so we can't really investigate"
Get the fuck out. I do write for GPU as well. One does not replace the other.
No one's doing database management on GPUs. No one's scraping data on GPUs. Can't run VMs on GPUs. Can't run web servers on GPU...
If you’re a 3D rendering designer, an ML engineer or a crypto bro, then sure.
Here are the common workloads (for the average SWE on HN) that use CPU/RAM:
Ok sure, top/htop is totally irrelevant now /s