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Htop Explained Visually

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Re: Htop Explained Visually

#22

Post by zeptomu »

torrent-of-ions wrote: post #17

I love htop. But I can't figure out a way to disable the CPU monitors. I use a machine with 768 cores which makes it kind of useless.

I don't have 768 machines, but considering one writes a hypothetical bug report, what would be the instructions to trigger or reproduce the bug?

Re: Htop Explained Visually

#24

Post by foob »

torrent-of-ions wrote: post #17

I love htop. But I can't figure out a way to disable the CPU monitors. I use a machine with 768 cores which makes it kind of useless.

Open `~/.config/htop/htoprc` and modify the line:

    left_meters=AllCPUs Memory Swap
to be

    left_meters=CPU Memory Swap
That will replace the default CPU monitor with a single meter for the average across all cores. After that, you'll be able to customize things the standard way by pressing F2 within htop.

Re: Htop Explained Visually

#25

Post by dom0 »

pmontra wrote: post #5

As a consequence of trying htop after a long time, I got a reminder that VIRT is not related to RES. I noticed Libreoffice Calc with 29.7 GB of virtual memory and only 198 MB actually used. I wonder why LO made a malloc of nearly 30 GB, but memory is cheap especially because it's virtual. The next one on the list is Firefox with 8.5 GB VIRT and 994 MB RES. By the way, I've got 16 GB of RAM and no swap. Anyway all tha…

RES isn't physical memory, either. I can happily have, say, 30 GB RES on a system with only 1 GB RAM (and no swap).

smem's measures - USS, unqiue set size (unshared pages) and PSS, proportional set size (shared pages divided by their share count, ie. how many tasks share them), are far more accurate and easier to reason about than RSS and VSS.

Re: Htop Explained Visually

#27

Post by cthalupa »

dom0 wrote: post #25
pmontra wrote: post #5

As a consequence of trying htop after a long time, I got a reminder that VIRT is not related to RES. I noticed Libreoffice Calc with 29.7 GB of virtual memory and only 198 MB actually used. I wonder why LO made a malloc of nearly 30 GB, but memory is cheap especially because it's virtual. The next one on the list is Firefox with 8.5 GB VIRT and 994 MB RES. By the way, I've got 16 GB of RAM and no swap. Anyway all tha…

RES isn't physical memory, either. I can happily have, say, 30 GB RES on a system with only 1 GB RAM (and no swap). smem's measures - USS, unqiue set size (unshared pages) and PSS, proportional set size (shared pages divided by their share count, ie. how many tasks share them), are far more accurate and easier to reason about than RSS and VSS.

Well, RES is physical memory, it's just some places where it gets reported don't account for physical memory that is being shared between multiple processes.

If I have a process that says it's using 1GB of RES, then you can guarantee there is at least 1GB of physical memory in use. It just might also be in use by other things also reporting their own RES usage.

Re: Htop Explained Visually

#29

Post by zer0t3ch »

platz wrote: post #28

what are units of load average?

I can't think of a good way to put it without just giving examples, so here goes:

    1.0 = 100% usage of a 1-core system
    1.0 = 50% usage of a 2-core system
    4.0 = 50% usage of an 8-core system
    8.0 = 100% usage of an 8-core system
And IIRC, load average is represented usually as 3 numbers, which are over the last 5, 10, and 15 minutes.
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